Date: Wed, 06 Jan 1999 05:34:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Four rotor based on two 13B's.
MAR34807@aol.com wrote:
Info that could be useful!
Subject: Re: 3 or 4 rotors
From: "grant robbins" <grannys@sos.net>
I built a 4 rotor out of a couple of 13Bs a few years ago. Had to build-up
the eccentric shafts and machine in a coupling I designed. I stripped
everything off of the front of the rear engine's front housing and the two
engines mated with only a 3/8" aluminum plate between them. The oiling
system was near stock on the front engine except for a special sprocket and
chain I made to drive the big pump at twice speed and a bigger / longer
pickup tube. An oil pan was fab'd to fit across both engines to provide a
common sump. An external manifold supplied oil to the rear engine. The
water pump was modified to pump into an external manifold and then y'd to
feed both engines from the top of the center housings. A large pilot dowel
was made to align the engines that centered the rear main seal bore of the
front engine with the front main bearing bore of the rear engine. The
eccentric shaft coupling passed thru the middle of it.
The engines were
timed in sync with each other to cancel the effects of eliminating the
center balance weights. Only the front thrust bearing was used. The two ecc.
shafts had a drawbolt thru the front shaft that kept the coupling together.
The hard part was designing a coupling that could take the punishment and
still pass thru the ecc. shaft bearings (not easy).
Several other minor mods
were made to oil / water passages to make it work. I used the stock
distributor on the front engine, modified it with a solid point plate and a
pair of accel points, and used it to fire only one plug per rotor. I spent 2
years making it all work and building a new car to put it in ( an 1800 lb
dirt late model ).
I raced it off and on for a season and a half before I
got burned out. It was competitive against the Alky burning injected 700 hp
Chevys and Fords that are typical in the class. Had to use the lowest change
gears in the quickchange I could find. The biggest drawback for me was that
everything had to be hand made and I was working by myself and funding the
project. My business began taking off, and I had less and less time to put
into it.
The final straw was when I knocked off an oil fitting. Faced with
tearing the whole engine completely apart just to check the
damage and then building new shafts, I just built a Chevy like the rest of
'em cause I could just go buy the parts for that. I've got some pictures of
the engine in the car that I'll post on my website when I get them scanned.
When I do, I'll post to the group to let you know.
Grant
GRANNY'S SPEED SHOP
for more info on our Mazda RX-7 V-8 kits......
http://members.tripod.com/~grannys/index.html
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______________________________________________________
Date: Wed, 06 Jan 1999 05:36:54 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: 13B on Dyke Delta
MAR34807@aol.com wrote:
Anyone seen Tracy Crook's latest newsletter? In it there is a picture of Kelly
Troyer's 13B on his Dyke Delta. Looks like he used a plate between the
bellhousing and motor to mount the motor mount frame to. Looks real nice. More
of what I had in mind for a motor mount arrangement. Is he on the list?
On the subject of the constant speed PSRU, I called and was told the unit fits
Chev V8s and can be adapted to Ford V8s, and costs about $9000. Steep. When
Fred died it went to an outfit in Oregon who is now selling them. Looks like
we would need an adapter to make it work, or another bellhousing
cast..........more weight....
It uses a hivo chain.
Paul, it is not the same outfit that made belt drives!
I stand corrected.
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 05:29:54 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Single rotors.
LENSIMPSON@aol.com wrote:
is there a single rotor available for a hopped up par 103?
thanx len
See the NL web site for the Wankel web page and Paul Yaw's web page.
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 05:47:24 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: EGT sensors for EFI
rws@altavista.net wrote:
I have also mentioned adding an EGT sensor to Tracy
on his computer.
Paul
I have considered this and may do it if I can find a way
around the problems that come up. One is reliability. EGT sensors
are not very long lived at rotary EGTs.
I got about 200 hrs out of the low cost ones and hope to get 500 out
of the expensive type but even that is not good enough in an airplane.
Have you tried moving them down the pipe to a cooler spot?
The other problem is response time. Not a problem in a car when
running relatively rich mixtures (compared to cruise in an airplane)
but the delay would cause the engine to cough & die in some
situations.
If the response time of the EGT sensor is slow the changes in mixture
have to be small. It would take some time to optimize. Not a problem
in cruise. The throttle position would probably have to
be taken into consideration by the software as well to determine
a rapid change in throttle position. [P]
In actual practice, I find that the manual mixture control on the EC1
and the "human closed loop" reading the EGT is not that big a deal.
What it boils down to is two adjustments per flight. I set it to
mid-range for takeoff and landing and lean it once at altitude. The
work load is well worth the reliability gained with simplicity.
Tracy
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______________________________________________________
Date: Wed, 06 Jan 1999 05:50:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Mini 500 rotary
KHood wrote:
Hello Paul
Spoke to Phil Williamson and he informs me that you have a
newsletter that you put out concerning the Wankle in aircraft
applications.Would it be possible to be put on your list? I have a
mini-500 and am interested in any alternatives to the rotax. Should
you know of anyone who has already done this conversion or has any
info on it would you be so kind as to pass it on.
Thanks
KIRT HOOD
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______________________________________________________
Date: Wed, 06 Jan 1999 05:59:47 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Oil Temp Problem Solved?
Anderson Ed wrote:
Hi Paul,
Hope you had a Merry Christmas. Thought I would report on the latest
(and hopefully the last) mod to cure the oil temp overheat problem I
have reported on several times.
I now have 3.5 hours flying time with the latest mod and am happy to say
I can now fly without keeping an eye on the oil temp all the time.
The 5" dia duct appears to bear out the calculations results and I make
take off for the first time without my oil temp going over 220F. I
normally have to throttle back after hitting 120 IAS to permit the oil
temp to decrease below red line (210F).
This time I was able to maintain WOT (T.O at 5200 rpm) until I hit 180
IAS at 1500 ft (6000 rpm). The oil temp did not increase beyond 200F
Yes!. In fact, the oil temp on these two flights has ranged from 160F
to 210F (in a long climb at WOT). Before, it would range from 190-240F,
with the higher temps at WOT. Now, the OAT was only 15F so this was not
the 90F+ acid test, but with the previous 3" dia duct, it would not cool
even on 15F days.
So, it appears the calculations were worth the effort. A 5" dia air
duct feeding a oil cooler plenum with duct entrance to the plenum 8"
from the surface of the oil cooler is optimum based on my calculations
from my size oil cooler (8x11x2).
Now that I can run WOT without melting down my 13B I have a question.
I notice at WOT at 5000 MSL I get around 6000-6100 rpms, but my manifold
pressure is 23 inches. I would have expected to have it nearer 25-26
inches at WOT. I have a foam filter, 3 feet of 3"dia duct and an airbox
over my throttle body. The airbox covers two flared intake nozzels, one
for each throat of the throttle body and the top of the box is about
1.75 inches from the opening of the flared nozzels - could this be too
close. I think I will try a flight with the top of the airbox open to
see if that makes any difference. Any thoughts on the topic??
Have a Happy New Year
Ed Anderson
anderson_ed@bah.com
RV-6A 13B powered 15 hours flight time
What should it be at 5000 feet? I don't have the formula or a chart
in front of me at the moment. If it is much less it is indicative
of losses in the intake plumbing of course. You said that :-)
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 05:49:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: OIL COOLERS
Bulent Aliev wrote:
Oil Coolers for Experimentals....just got this out of a new magazine
Private Pilots "CustomPlanes" They make Oil/coolers of 4" to 6" header
to header...go to http://www.oil-coolers.com
Bulent
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______________________________________________________
Date: Wed, 06 Jan 1999 06:02:20 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Another Mustang II with 13B
Rosine, Steve wrote:
I'd like to be added to the mailing list. My project is a Mustang II
(80% complete) with non-turbo R13B. I have been following Tracy Crook's
conversion guide, and have ordered his engine controller.
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Date: Wed, 06 Jan 1999 05:53:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: PC based glass cockpit
marc wrote:
For those who are interested, my brother has now posted on his webpage the
parts list and prices for the components that make up his company brewed
flatpanel cockpit PC for $1500.......of course this is not a "certified,
approved, and tested flight instrument" approved by those great FAA guys in
the avionics section! It is going in my Seawind (a kit), tho.......
Marc Wiese, C177RG, N34807
I'm very interested in having such a PC in my panel!
More info please? How large a spot in the panel does it consume?
Paul, Berkeley
Hi,
I'll send the info off by the 2nd week in Jan.
kahuna@cftnet.com ( BearAir )
http://www.cftnet.com/members/kuhuna/bearair1.htm
****************************************
"When facts are few, experts are many."
Donald R. Gannon
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______________________________________________________
Date: Wed, 06 Jan 1999 06:05:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: RV6 motor mounts/thrust line.
QmaxLLC@aol.com wrote:
Tracy's book suggests a thrust line position. However, I asked Van of Van's
aircraft about the position and he shrugged stating that I should just center
it up and not worry about it.
Bob Fritz
RV6
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Date: Wed, 06 Jan 1999 06:15:54 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
CC: canard-aviators@canard.com
Subject: [Fwd: [canard-aviators]
Bulent Aliev wrote:
Hi Paul, the following email was posted on the canard aviators mailing
list. I think you are qualified to give the answer.
Hope your trip to FL was enjoyable.
Bulent in Ft Lauderdale FL
---------------------------------------------------------------
Subject: [canard-aviators] Re: Questions???
Date: Wed, 30 Dec 1998 19:01:31 -0500
From: "Dorothy Dickey" <mreracer@primenet.com>
To: <canard-aviators@canard.com>
[The Canard Aviators's Mailing list]
I do not recommend rotory engines of any kind for experimental
aircraft. They have numerous deficiencies as compared to other more
conventional engines...
After 12 years of experimenting with auto engines I have come to the
conclusion that you can not do a successful auto conversion for less
money than an aircraft engine, and the only way to improve performance
over an aircraft engine is to spend tons of money... So why do it?
I define a successful auto conversion as one that is cheaper and
delivers greater performance and reliability than the A/C engine it
replaced. There are a lot of auto engines flying out there, but not one
of them meets this criterion...
Shirl
http://www.canard.com/ca-ending.html
Now here is a man with a lot of experience with auto piston engines
in airplanes but not much with rotary engines. I agree with him about
automotive piston engines but I disagree about the rotary engine.
Shirl Dickey meet Tracy Crook :-)
Paul Lamar
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______________________________________________________
Date: Wed, 06 Jan 1999 06:06:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Good reading about 13BT vs 13B-REW
Craig Pugsley wrote:
Hi guys,
http://www.engr.ucdavis.edu/~pko/13BTvs13BREW.html
Has a good article about the older 13B turbos and the newer 13B-REW (3rd
generation RX7 engines). Goes into detail about why the 13B-REW is
better for 400+ hp applications.
Cheers,
Craig.
clag@geocities.com
http://members.xoom.com/craigpage/INDEX.HTM
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Date: Wed, 06 Jan 1999 06:20:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Oil/water heat exchanger/pan fabrication.
Marvin Kaye wrote:
Hi Paul,
Just to let you know, my engine mount is coming along nicely, I've only got
about 6 more tubes to go, then it'll be time to run the whole shootin match
over to the welding shop to let them TIG over all my gas-applied tacks.
SPeaking of welding, I took a shot at welding those .035 wall AL tubes into
a sample of the .125 AL sheet stock. They went together nicely!! I
drilled the holes for the tubes their exact size, and when I inserted the
tubes into the flat stock I left about 3/16" of them protruding above the
sheet stock. I heated the sheet stock only, and let the residual heat work
on the tubes. My plan was that the 3/16" lip would soak up a little of the
heat, and then melt down into the puddles... as it turned out, I found that
I wound up using very little filler rod, as the protruding tubes wound up
filling themselves. Tomorrow I"m going to practice on a mockup of pan
sides, just to see what will happend when I've got to deal with the spacing
between the tubes at only about 1/2". If the real thing goes as nicely as
the experiment did, I"ll be very happy.
<Marv>
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Date: Wed, 06 Jan 1999 06:27:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: My position
ckgurr wrote:
Paul
Last I heard you were blasting all auto conversions, What caused the change
of heart and caused you come on board with the Mazda crowd?
Regards,
Carlos
--
Carlos K. Gurr
micron Technology Inc.
Lehi, Utah
(801) 767-4832
mailto:ckgurr@micron.com
The perception was wrong. I have always thought the rotary would
make a good aircraft engine.
Tracy Crook proved it.
I can send you some real old messages of mine touting the rotary
from Genie if you wish :-).
Paul
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Date: Wed, 06 Jan 1999 06:31:21 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Old issues of the newsletter.
Gordon Haggard wrote:
Dear Sirs:
In regards to a letter posted on the Matronics RV server, your
address was given as a source for a rotary engine newsletter update.
Having read Tracy Crooke's book and being a RV6 builder, I would like
to have my name added to your newsgroup. Is it possible to download
previous postings or have them sent?
Thanks,
Gordon Haggard
gordon@sssnet.com
Not at the moment Gordon. We are working on several books however.
Paul
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Date: Thu, 07 Jan 1999 06:01:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: SWAG/Aero Steve Parkmans fatal crash.
We lost a brilliant engine system computer programmer in a crash
of an auto engine powered Vari-EZ.
Unfortunately Steve was taken in by all the hype around
automotive piston installations in expeirmental aircraft.
He had roughly a 90 cubic inch Geo Metro engine in a Vari-EZ
designed for a 200 cubic inch Continental O-200 AC engine.
Steve unrealistically believed you could get 87 real HP out of the
Geo engine and thought the weight would be roughly the same
as a 100 real HP Cont. O-200. Steve himself was no light weight.
His prop may also have been less than optimum for climb.
Here is the NTSB prelim report.
Paul
NTSB Identification: LAX99FA052
Accident occurred DEC-18-98 at TUCSON, AZ
Aircraft: Parkman VARI-EZE, registration: N81EZ
Injuries: 1 Fatal.
This is preliminary information, subject to change, and may contain
errors. Any errors in this report will be corrected when the
final report has been completed.
On December 18, 1998, at 0815 hours mountain standard time, a
experimental Parkman Vari-Eze, N81EZ, collided with a
mesquite tree during a forced landing attempt in the desert just east of
Ryan Field, Tucson, Arizona. The aircraft, which was
constructed and owned by the pilot, was destroyed during the impact
sequence and subsequent postcrash fire. The pilot sustained
fatal injuries. Visual meteorological conditions prevailed for the local
flight. The pilot had just departed Ryan Field for the
maiden flight in the aircraft when he contacted the control tower and
told them that he had a problem and that he "had to put it
down here." Air traffic controllers who were interviewed after the crash
stated that the aircraft did not appear to gain much
altitude, only achieving about 100 feet of altitude above the terrain.
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Date: Wed, 06 Jan 1999 06:22:39 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: EFIS
marc wrote:
Happy New Year! And take a look at this! Great EFIS stuff!
http://www.sierraflightsystems.com/index.html#anchor85334
Do the sim at http://www.sierraflightsystems.com/Demo.html
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______________________________________________________
Date: Wed, 06 Jan 1999 06:43:13 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Inverted aerobatic 13B conversion
G. A. Loeffler wrote:
Dear Paul,
I'm listening to your rotary list for a
while. My engine alternatives for
kitplane to be started soon (Italian
Storm 300 kitplane) would be either a:
MidWest 110R or b: doing my own 13B
conversion.
My questions: 1. how much
money could be saved by own conversion?
Not much and it would be heavier.
2. what (special) tools are required for
conversion/cost of tools?
If you rebuild a Mazda some special tools are required
I would invest in a shop manual for a list of those
that are needed.
3. Where can I
get a book/detailed instructions for
conversion.
Tracy Crook at rws@altavista.net
4. The rotary's lubrication
and fuel injection looks quite good for
inverted flight. What other mods should
be done for aerobatics use?
You will need a dry sump oil system with scavenge pumps
at the top and bottom of the engine.
kind Regards
G. A. Loeffler
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Date: Wed, 06 Jan 1999 06:46:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Australia Rotor Craft with 13B's
Colin Smith wrote:
Goodmorning Paul,
I am a technical advisor for Aust. Sports Rororcraft Assoc., and am
designing/building (with help) a two place side by side gyro powered
with a 12A turbo rotary. Please put me on your rotary engine newsletter
mailing list.
I subscribe to Tracy Crook's R A N and meet him 1997 at Osh. This year
1999 I will be at Bensen Days and Sun'n'Fun. May meet you there.
Thanks, Colin
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Date: Wed, 06 Jan 1999 06:52:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Mazda 12A oil/water heat exchanger
Richard Sohn wrote:
Hi Paul!
I am back from my trip and have another 12A 1985 in my inventory. This
model has an oil/water cooler. What is the reason that nobody ever
mentions this in the related discussion?
Look forward to receiving the mail again.
Richard.
Consider it mentioned :-)
Its fine for a one rotor but not up to the job
for a two rotor. The rotary engine used in an aircraft
generates a lot more continuous power than
it does in a car so more oil cooling is required.
Won't hurt for a plugs up 13 B
however as it sticks up too far on an upright
13B. You will need additional oil cooling.
Paul
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Date: Wed, 06 Jan 1999 07:03:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Peak cyclinder pressure in diesel engines.
Jeff Spitzer wrote:
At 12:38 AM 12/21/98 -0800, you wrote:
I don't think the combustion pressure is quite that high Gerry.
Let's see four inch bore... 12 square inches... 315 tons. I think you
Have one extra zero there. 1000 psi should be more like it.
I checked my copy of Taylor "The Internal Combustionm Engine in
Theory and Practice" and the Cummins twin turbo 475 855ci listed
has a bmep of 210 psi. Thats sort of like average pressure.
Peak pressures for diesels are in the 800 to 1100 psi range.
Volume 2 page 100.
Paul
Those numbers are kinda low Paul. Our engine is designed for 2000 psi peak
pressures which is more on the high side of average. Most commercial
engines run 1800 or so. Much higher and piston rings become a real
problem. A turbo gas engine will exceed 1100 psi.
Jeff Spitzer
Jeff Spitzer is our resident engine design engineer.
He is project engineer on the General Atomics opposed piston
turbo charged aircraft diesel engine. He was also the project
engineer on the Moller Skycar rotary engine.
Thanks Jeff.
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 07:06:23 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Oil pan heat exchanger transfer rates
Jeff Spitzer wrote:
At 03:24 PM 12/21/98 -0800, you wrote:
Jeff brought this up some time ago.
Notice that the heat transfer can be increased by a
factor of ten if nucleate boiling is allowed to occur
in the coolant tubes.
In other words;
If the oil gets too hot & causes the coolant to boil
in the coolant tubes the heat transfer
jumps up and self regulates much more strongly.
This is from Marks tenth & latest edition MSH for ME's.
Page 4-87
Paul
" Boiling Liquids.
The nature of the heat transfer from a submerged
heater to a pool of boiling water is shown in Fig. 4.4.5. Other liquids
exhibit the same qualitative features. In the range AB, heat transfer to
the liquid occurs solely by natural convection, and evaporation occurs
at the free surface of the pool.
In the range BC, NUCLEAT BOILING occurs.
Bubbles form at active nuclei on the
heating surface, detach, and rise to the pool surface.
At point C, the heat flux passes through a maximum at a temperature
difference called the critical delta-t In the range CD, transitional
boiling occurs.
At point D, the transition is complete and the heating
surface is completely blanketed by a vapor film. This is the point of
minimum heat flux, or the Leidenfrost point.
In the range DE, the heating surface continues to be
blanketed by a vapor film.
The range AB is adequately correlated by the usual natural-convec-
tion equations.
No truly adequate correlation is available for the
range BC because the complex processes of nucleation and interfacial
interaction are only partially understood. However, the relation due to
Robsenow (Trans. ASME, 74, 1952, pp.969-976) is one of the best and can
be reliably used for modest extrapolations of existing data."
The chart you attached is for a stagnant situation where the vapor film is
not "washed away". In the flowing case of a hybrid cooling system the heat
transfer was found to continue to rise exponentially for any reasonable
heat transfer rate.
Jeff Spitzer
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______________________________________________________
Date: Wed, 06 Jan 1999 07:11:17 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Wanted three rotor.
Mark Goodley wrote:
ok,
So where can I get a clean turbo 3-rotor.
--
Thank You,
Mark Goodley
Visit our web site at:
<www.agtechinternational.com>
Good question? Anybody have a three rotor for sale?
Paul
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Date: Wed, 06 Jan 1999 07:20:36 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Brice Dauney's phone/ e-mail address
Tom P. wrote:
Paul Lamar -
Peter Garrison referred me to you. I'm trying to contact Brice Dauney
regarding his Mazda 20B installation in his Velocity, but have had
little luck.
I'm finishing the airframe of my Lancair ES, and am very interested in
a similar engine installation. I'd prefer not to reinvent the wheel,
if you or he can provide any assistance.
Thanks,
Tom Parkes
Brice is on here perhaps he will respond.
Brice Daunay <Briceair@worldnet.att.net
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 11:11:38 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Manifold pressure drops in intake systems.
Anderson Ed wrote:
It drops approx 1" for each 1000 ft so I should read around 25" at 5000
ft, but can only get a max of 22-23.
Ed
I would think that is not too far off typical Ed.
Intake systems have losses. The Mooney has a flap
that bypassses the air cleaner for about a one inch gain
at altitude where you don't need the air cleaner.
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 11:13:12 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: RV6 motor mounts/thrust line.
Anderson Ed wrote:
Bob, on my 13B powered 13B, I offset the thrust 5/8" to the left
(looking from pilot's seat) from the center line shown in the plans for
the RV (look at the motor mount drawing). I still need left rudder on
take off and lower speeds to keep ball centered so probably should have
offset a bit more. But, at cruise 170 IAS plus the ball is centered
without any rudder input. So 5/8" worked fine for me.
Ed Anderson
anderson_ed@bah.com
RV-6A N494BW 15 hours
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______________________________________________________
Date: Wed, 06 Jan 1999 11:14:27 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Wanted three rotor.
Gerry Hess wrote:
Ichiban Rotary in Austrailia has had 3 rotors listed at $3900. Their site
does not show one at present, but contact them and they will probably have
it. Aussie dollars are about 40 cents US!
They are at http://www.ozemail.com.au/~japeng/
Gerry Hess
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______________________________________________________
Date: Wed, 06 Jan 1999 11:18:17 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Oil Temp Problem Solved?
Jeff Spitzer wrote:
At 05:59 AM 1/6/99 -0800, you wrote:
Anderson Ed wrote:
Now that I can run WOT without melting down my 13B I have a question.
I notice at WOT at 5000 MSL I get around 6000-6100 rpms, but my manifold
pressure is 23 inches. I would have expected to have it nearer 25-26
inches at WOT. I have a foam filter,
Start here. The foam filters are the worst for pressure drop vs. cleaning
efficiency. Best is K&N by a large margin followed by conventional paper
with foam a very distant third. It is possible that if you don't have a
HUGE foam filter that it is you total problem. Go to K&N.
Jeff Spitzer
What and where do we get "K&N" Jeff?
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 13:54:39 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Pressure drop in intake system.
Jeff Spitzer wrote:
What and where do we get "K&N" Jeff?
Paul
K&N Engineering
Riverside, CA
(909) 684-9762
www.knfilters.com
Or many aftermarket replacement filters for auto apps available at speed
shops.
Jeff Spitzer
--
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______________________________________________________
Date: Wed, 06 Jan 1999 13:52:07 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Pressure drop in intake system.
Anderson Ed wrote:
Thanks Jeff,
My filter is 3" dia with two 1" layers of fairly corase foam in the air
flow (I believe it is K&N, but not certain). This is followed by three
feet of 3" duct before dumping into the airbox. Easy enough to check by
removing the lid from my airbox and allowing the air to flow directly
into the two air horns of my dual throat (50mm each) throttle body.
Paul, I got my K&N (if it is K&N -been a long time since I purchased it)
from Summit racing
Ed
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______________________________________________________
Date: Wed, 06 Jan 1999 13:53:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: zz <rotaryeng@earthlink.net>
Subject: Pressure drop in intake system.
Carl Stevens wrote:
On Wed, 6 Jan 1999, Paul wrote:
HUGE foam filter that it is you total problem. Go to K&N.
Jeff Spitzer
What and where do we get "K&N" Jeff?
Paul:
K&N are a group that make filters for allsorts of racing
applications. You can find them at most any speed shop and
they may even have a web page, I'll do a search later. They
are good filters, washable, and have a good life expectancy.
I used to run them on my Baja bug, a tough enviroment by
most anyone's standard.
Carl
--
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______________________________________________________
Date: Wed, 06 Jan 1999 21:30:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: zzasmaa <rotaryeng@earthlink.net>
Subject: My own design...
Ramon Collado. wrote:
Hello Paul, I am building a four place, low wing, all wood airplane, that
I named myself SAREN. I plan to install a 13b, which is already on the
overhaul bench, and one of my biggest design problem was the engine mount.
Thru your newsletters I have seeing differents mounts arrangements, and I
wish someone would show the tubings diameters and thickness being used on
these mounts.......They would really help me ....Thanks
Ramon
We have not been able to determine a tubing size for any of these mounts
so far. I am still negotiating for the use of an FEA program for this purpose.
If you don't mind a little extra weight 7/8 dia. by .065 wall 4130 should
be overkill for almost any configuration. The top tubes in tension could
be 3/4 by .049 wall. Wrap all joints with .049 sheet 4130.
Send me the dimensions of the mounting points on the firewall and I will
draw something up for you. I will also need the distance from the firewall
to the prop flange and the position of the thrust line.
BTW to test a motor mount you can use the whole airplane as a lever
to raise the front end of an average mid size car, wheels and all, clear
of the ground. You do this by pushing down on the horzontal stablizer spar
near the root or loading 50 pound bags of cement on to the horz. stab
untill the wheels of the car are clear of the ground.
The main landing gear will act as the fulcrum point.
For a canard the situation is reversed. You push down on the canard
spar.
If your motor mount design can do this it should be strong
enough for a six G pull up.
I came up with this apparently crazy idea after I tried to figure
out where the average builder was going to get 1800 pound of dead weight
to static test his motor mount.
I will do a drawing of this soon and upload it to my web site.
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 21:33:27 -0800
From: Paul <rotaryeng@earthlink.net>
To: zzasmaa <rotaryeng@earthlink.net>
Subject: Pressure drop in intake system.
Jeff Spitzer wrote:
Anderson Ed wrote:
My filter is 3" dia with two 1" layers of fairly corase foam in the air
flow (I believe it is K&N, but not certain). This is followed by three
feet of 3" duct before dumping into the airbox. Easy enough to check by
removing the lid from my airbox and allowing the air to flow directly
into the two air horns of my dual throat (50mm each) throttle body.
Ed
K&N may sell some foam units but when I say K&N I'm referring to the oiled
gauze (sp?) units. If I understand your filter as air flowing through 2"
of foam with a 3" diameter then my reaction is OUCH! That is definately
the 2" of pressure drop your looking for. A foam filter for a 13B should
have 150++ sq in of cross section to flow through not 7 sq in. Take the
filter out, find your missing pressure, then go find a proper K&N gauze
type filter. BTW, the clearance you cited for airbox to trumpet height
doesn't sound restrictive.
Jeff Spitzer
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______________________________________________________
Date: Wed, 06 Jan 1999 21:39:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: zzasmaa <rotaryeng@earthlink.net>
Subject: Mazda 12A oil/water heat exchanger
MAR34807@aol.com wrote:
Even on the rx7 car that oil/water cooler was considered a bad design item.
Most have been replaced with the air oil cooler. I think even Tracy C even
tried it and found it was no good.
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______________________________________________________
Date: Wed, 06 Jan 1999 21:42:37 -0800
From: Paul <rotaryeng@earthlink.net>
To: zzasmaa <rotaryeng@earthlink.net>
Subject: RV6 motor mounts/thrust line.
Finn Lassen wrote:
Sure, if you can live with a bigger "bulb" on top of the cowling for the alternator
( go with a smaller alternator).
An alternative I thought of is two small alternators: one in the standard position
and one mounted on the water pump housing (I think the air pump or some such
normally is mounted there on the RX-7).
Finn
Paul wrote:
QmaxLLC@aol.com wrote:
Tracy's book suggests a thrust line position. However, I asked Van of Van's
aircraft about the position and he shrugged stating that I should just center
it up and not worry about it.
Bob Fritz
RV6
Or make a new bracket and mount the alternator on the side of the engine.
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 21:51:38 -0800
From: Paul <rotaryeng@earthlink.net>
To: zzasmaa <rotaryeng@earthlink.net>
Subject: Turbocharging
V. E. Welch wrote:
I have been considering a 13B for an RV-8 project. I would like a
turbocharged unit for altitude work. Have any of you looked into this? Is
Mazda's stock turbo workable or would I need to do some modification?
Should I look at a different type of turbo (non-automotive)? Would a
supercharger be preferable to turbocharging? Just trying to determine how
deep these waters are going to get before I jump *smile*
Vince
I would not use the stock turbo charger. I don't think it is durable
enough. Check with Turbonetics for a turbocharger with an Inconel
turbine and fabricate an Inconel exhaust manifold.
There is a link on the NL web site for Turbonetics. Don't tell
them it is for an aircraft.
Make sure you use an intercooler. Detonation can break the apex
seals and scratch the rotor housing. The engine won't stop but
it will gradully lose power over time. Use a late turbo engine
with the knock sensors mounted on the rotor housing just above
the spark plugs.
A supercharger will work but the heat load on the engine will be higher
than a turbo for the same boost.
Paul
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______________________________________________________
Date: Wed, 06 Jan 1999 21:57:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: zzasmaa <rotaryeng@earthlink.net>
Subject: Finn's 13B update
Finn Lassen wrote:
Welcome home Paul! And thanks for changing to my new e-mail address.
I purchased two new main bearings, two rotor bearings and a new oil
pump, all from mazdatrix. I managed to press the old main bearings out
and the new in simply using my vice. I took the two rotors to a auto
shop and used their press for the rotor bearings.
As for polishing the e-shaft, I could easily have done myself after
seeing how it done: the machine shop guy simply mounted it in a bench
that slowly rotated it. He then used a handheld 1" 350 grit (long) belt
sander on the journals.
I finished assemblying the engine and mounting it back on the RV-3
January 2nd, and ran it for the first (successful) time for about 15
secs at low RPM. Great sound from my homemade muffler and 2" exhaust
pipe!
The reason I didn't run it longer was that I still didn't get oil
pressure. I then spent most of the weekend debugging the pressure
problem (and replacing a leaking center carb float). I'm still not 100%
sure of the cause, but I changed my bigger oil filter to the standard
small filter. I also turned the engine with the starter (no spark plugs)
for a longer time (30 - 45 secs) and suddenly the pressure came up! I
had been afraid of damaging the starter and had only run it for 15 - 20
secs at a time in my previous attempts to prime the oil system.
Currently it's too cold (in the evening) for my taste, so I'll probably
not have any more news until the coming weekend.
Finn
What are you now using for an oil pressure gage?
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 22:19:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
CC: Dave Martin <dave@kitplanes.com>
Subject: My position on car piston engines verses the rotary
Perry Mick wrote:
I went to an EAA chapter meeting in January 1996, where Everett Hatch
gave a presentation. He spent his whole life working on piston and
rotary engines for race cars and airplanes. He gave the presentation on
the work they (Powersport) were doing on the rotary. He said he would
never put an automotive piston engine in an airplane, they just weren't
designed for it. But he said the rotary was a different story. I'd
like to know what shortcomings Shirl Dickey thinks the rotary has.
Me too since, to my knowledge, he never tried one.
BTW I was thinking we ought to petition the EAA to give Everett Hatch
and Tracy Crook awards for furthering the cause of general aviation.
The way it looks now the rotary may be better and cheaper than a real
aircraft engine.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 22:34:42 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Priming the oil pump.
Finn Lassen wrote:
Well, now I know why you guys mount your filters "upside-down". And I
thought I was being smart in making a fitting to mount it the same way it's
"standardly" mounted on the engine.
Finn
Paul wrote:
Anderson Ed wrote:
Glad to see Finn has got his engine back together after the incident.
Whenever I change my oil (like once so far), I fill the new oil filter
and the oil cooler with fresh oil before cranking the engine. I also
disable the ignition and just use the starter to build up oil pressure
first. It generally takes about 5 seconds of cranking when the oil
filter and cooler are prefilled.
Ed Anderson
RV-6A 13B powered
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______________________________________________________
Date: Fri, 08 Jan 1999 09:52:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: EAA awards for Tracy Crook and Everett Hatch
I think we need to include Allan Tolle as a candidate
for those awards as he did most of the test flying
for Everett.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 22:28:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: WAS SWAG/Aero fatal crash.---- static thrust test]
Bob and Marnie Falkiner wrote:
Story #1:
It should be mandatory to verify static thrust prior to first takeoff. This
saved "my" bacon once when I incorrectly set the pitch of a ground
adjustable prop. I was going by static RPM. The test runs seemed to lack
oomph, and my test pilot didn't like the prop sound/noise. We compared the
static thrust with a $2.99 black rubber "bungee cord" compared to the old
prop (test took about an hour) and decided something was wrong. A quick
phone call to the manufacturer confirmed that I had dialed in way too much
pitch to get the static RPM down to "book" value, and the prop was probably
"stalling" at low/zero airspeed.
Moral: when you got something new, it really really helps to have something
old that you know works to compare it to.
Story #2
My building partner was having engine problems akin to a stomach flu -- lots
of symptoms but nothing that stopped the head scratching. Was it vapour
lock (like I had in spades), fuel mixture, fuel plumbing, bad cowling
cooling, ingnition, ignition timing.... really hard to diagnose these
"engine doesn't seem like its putting out" type problems. The only way he
knew that something was wrong was a degradation from previous performance.
If it was first flight, it would have been "normal". The answer, by the way,
was missing copper gaskets on replacement lower plugs when the plans
adjustment came out for the "standoff" piece in the revmaster. If this prior
experience was not there, how would he have known?
There has to be a way that homebuilders can verify adequate thrust prior to
takeoff cheaply and easily. I know that a bungee cord works. any other
ideas?
Check out my low cost dyno and static thrust stand design on the NL web site.
I use a calibrated garage door spring as a static thrust sensor.
Everett Hatch built a similar dyno for his engine overhaul business.
The trick is to sneak up on the proper pitch while recording the static
thrust as small changes in pitch are made.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 04:51:28 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Engine pressure/temp sensors.
Finn Lassen wrote:
Paul wrote:
Finn Lassen wrote:
...
The reason I didn't run it longer was that I still didn't get oil
pressure. I then spent most of the weekend debugging the pressure
problem (and replacing a leaking center carb float). I'm still not 100%
sure of the cause, but I changed my bigger oil filter to the standard
small filter. I also turned the engine with the starter (no spark plugs)
for a longer time (30 - 45 secs) and suddenly the pressure came up! I
had been afraid of damaging the starter and had only run it for 15 - 20
secs at a time in my previous attempts to prime the oil system.
Finn
What are you now using for an oil pressure gage?
Paul
Some old mechanical gauge. I'm planning on building an engine monitor, and
have been looking at sources for pressure senders. I'd really like to avoid
routing oil and water into the cockpit. Seems the most sturdy and reliable
(for the price) would be the SenSym 19mm 1/8"-27 NPT solid state steel sensor
@ $72 (page 530 DigiKey). An alternative is the $22.20 100psi Mitchell,
AircraftSpruce page 332 P/N 10-25045, but I don't know if that's a unreliable
mechanical sender. Anybody know? Or know of a cheap reliable alternative? Is
100 psi enough? (I have the standard 13B oil control and regulator valves.)
I'm also looking for a 30 or so psi water sender and 3 - 5 psi fuel sender.
Finn
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Date: Thu, 07 Jan 1999 04:49:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Priming the oil pump.
Paul Yaw wrote:
Finn Lassen wrote:
The reason I didn't run it longer was that I still didn't get oil
pressure. I then spent most of the weekend debugging the pressure
problem (and replacing a leaking center carb float). I'm still not 100%
sure of the cause, but I changed my bigger oil filter to the standard
small filter. I also turned the engine with the starter (no spark plugs)
for a longer time (30 - 45 secs) and suddenly the pressure came up! I
had been afraid of damaging the starter and had only run it for 15 - 20
secs at a time in my previous attempts to prime the oil system.
Finn
Hey Finn,
The oil pumps are normally very hard to prime unless you fill the pump
with oil, or use a heavy lube during assembly. If you installed it dry,
that may explain your problem.
Paul Yaw
Wow! That explains the whole situation. For those who came lately
Finn's orginal problem came from starting the engine up with
throttles stuck wide open, no oil pressure and no prop load. The
engine ran up to 10,000 + RPM estimated before Finn could shut it off.
The main bearings were moderately damaged and the e-shaft had
bearing residue soldered to it. The rotor bearings were almost
still useable.
Thanks for the great tip Paul. We need to get that into a how-to file
on overhauling the rotary.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 04:55:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Wanted three rotor. & the Aussie dollar.
Mr Greg Poole wrote:
Gerry Hess wrote:
Ichiban Rotary in Austrailia has had 3 rotors listed at $3900. Their site
does not show one at present, but contact them and they will probably have
it. Aussie dollars are about 40 cents US!
They are at http://www.ozemail.com.au/~japeng/
Gerry Hess
We are not quite the banana republic - yet! Try 61 cents US to the Aussie $
Regards,
Greg
Greg Poole (Building a Std RG Elite Velocity - "down under")
Wow that's amazing. Just about par with the Canadian dollar. Do you
suppose there is any connection?
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 06:03:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Steve Parkman
Ernesto Sanchez wrote:
I'm not sure. It was reported on the Canard Aviators E-Mail list that he
took off on the maiden flight and after a few minutes he reported trouble.
Next, someone saw a smoking crash site. Several folks are sending checks to
Mrs.. Steve Parkman to assist her in her time of need. His hangar mate
volunteered to handle the checks:
Jeff Gilbert
7788 S. Iron Bark CT.
Tucson, AZ, 85747
(520)574.7959
If I get more info I'll pass it on.
Thanks,
Ernesto Sanchez
es12043@utech.net
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______________________________________________________
Date: Thu, 07 Jan 1999 06:44:13 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Pressure drop in intake system.
Anderson Ed wrote:
Thanks Jeff,
Clearly, I under estimated the restrictive nature of my air filter. I
will remove the foam and take the aircraft for a flight. Gaining 2" of
manifold pressure and the resulting power increase will then give me the
power level I believe I should be getting out of the engine. Right now
I estimate based on aircraft performance that I am getting around 150
hp, gaining 2" should put it closer to 160HP or a tad more.
Ed
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______________________________________________________
Date: Thu, 07 Jan 1999 06:47:58 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Priming the oil pump.
Anderson Ed wrote:
Glad to see Finn has got his engine back together after the incident.
Whenever I change my oil (like once so far), I fill the new oil filter
and the oil cooler with fresh oil before cranking the engine. I also
disable the ignition and just use the starter to build up oil pressure
first. It generally takes about 5 seconds of cranking when the oil
filter and cooler are prefilled.
Ed Anderson
RV-6A 13B powered
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______________________________________________________
Date: Thu, 07 Jan 1999 06:42:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Wanted three rotor.
David Morris wrote:
G'day to Mark.
DMRH down under here.
REDLINE rotary here in Sydney had 8 20B engines ordered a few months ago
but only 5 arrived. The Japanese contacts decided to sell 3 of them
after getting last minute BIG offers. REDLINE since sold all 5 for well
over U.S $5000 each (& they were all used).
I was down there the other day & they were excited. There Japanese
conact found another 5. (Do you realize how rare that is these days) So
they are now on there way. I'm sure REDLINE will be asking well over the
U.S $5,000 mark as the others went instantly at that price.
Check them out at the below URL if you wish & ask about supplying some
to the U.S.
http://www.3rotor.com/redline
REgards
David Morris
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______________________________________________________
Date: Thu, 07 Jan 1999 07:00:54 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Engine pressure/temp sensors.
Anderson Ed wrote:
Finn,
I use a 0-135 psi oil gauge and sensor. My nominal oil pressure range
is 70-85 psi and this scale puts the needle in the green about the
middle of the gauge. I use a 0-30psi UMA fuel pressure sensor and gauge
for the coolant pressure. The UMA folks made me a new placard inside
the gauge that reads "Water Pressure" instead of the normal "Fuel
Pressure". I have a 24 psi radiator cap and my coolant pressure
generally runs between 15 and 20 psi. Coolant pressure drops down
considerably when the coolant temp drops below 150F (I don't have a
thermostat). In fact, all my engine instruments from tach,
oil-fuel-coolant parameters of pressure and temp use UMA. I found their
appearance and scale width what I wanted and the cost fell between auto
type gauges and aircraft gauges. However, they do have a permanet
magnet and therefore forced me to put my whiskey compass over on the
other side of the panel. Clearly any of the digital readouts avoid this
problem.
Ed Anderson
anderson_ed@bah.com
RV-6A N494BW Mazda Powered
Vienna, VA
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______________________________________________________
Date: Thu, 07 Jan 1999 09:00:05 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: SWAG/Aero Steve Parkmans fatal crash.
Anderson Ed wrote:
I think we all feel a keener sense of our own mortality when a fellow
experimenter/flyer meets with misfortune. Keenly sorry to hear about
Steve, I though some of his insights to EFI were helpful to many.
Unfortunately Paul, I must agree with you that - too many (not all,
certainly) espouse too much in terms of realistic performance of auto
conversions - some of whom have a $$ interest in presenting
unsubtantiated and/or unrealistic power claims to sell their "products".
As much as I would like to claim my 13B is producing 180-200 hp, the
peformance figures to-date clearly show that I am only getting about 150
hp at WOT. While this is adequate for the RV-6 design, it is on the
bottom end of the desired engine HP for this platform and less than I
will settle for. However, I recognize that this is a limitation of my
design and subsystems and not a limitation of the 13B. I realistic
expect to get 165 to maybe 170HP when I get all the bugs worked out.
And in fact, suggestions from many on this list have greatly contributed
to the resolution of my auto conversion teething problems and my
personal safety. From the fluctating oil pressure, foaming oil problem,
and now Jeff's insight into my overly restrictive air intake fitter set
up (which probably accounts for my missing 10-15 hp) have all benefitted
from the experience and knowledge of folks on the list.
Your list and the knowledge base available on it is the type of thing
that I believe any group interested in auto engine conversion needs to
have (regardless of the engine involved).
But ultimately, all of us who are experimenting with auto conversions
for aircraft use, have to acknowledge that it is not the same as
experimenting with a engine in a car (which itself can be dangerous)
which you can pull off the side of the road if it malfunctions.
There is no question that experimental engines in experimental aircraft
do increase the risk factor to some degree - mostly dependent, I
believe, on how seriously and well the experimenter assesses and plans
for the risks involved. But, even given that done well - the risk will
always exist. My design philophy is to assume failure modes WILL happen
and then attemp to come up with feasible backup/redundancy that
minimizes risks during the most critical phases of engine operation.
I could probably be rightly accused of being somewhat annal retentive
when it comes to my own butt {:>}. At least, I think my ground crew mayhave thought that when I handed out hatchets to them for breaking the
canopy should the need have arose, phone numbers of the closest fire and
resuce units, and the ER of the cloest hospital along with my blood
type,etc. Fortunately all unneeded on my first flight.
Thanks again Paul, for this forum. Lets hope it contributes to
lessening the possiblity of such unfortunate events that caught Steve.
I think it will.
Ed
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______________________________________________________
Date: Thu, 07 Jan 1999 09:09:54 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Static test for motor mounts.
Here is my drawing for static testing your motor mount design
using your car as the 1800 pound test load.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 09:29:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: New page..
Craig Pugsley wrote:
Hi,
Apparently I've got hours on end to spend surfing the web (well, it is
3:20am and I'm at home on holidays).
Got a pointer to a new page today..
http://www.hurley-engineering.ltd.uk/
This guy was making multi (3+) rotor engines years before 20Bs were
available. He has a picture of a 6 rotor engine, Can't quite tell if it's
real or just a mock-up.
Cheers,
Craig.
http://members.xoom.com/craigpage
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______________________________________________________
Date: Thu, 07 Jan 1999 11:21:41 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Air filters & air consumption
Chuck Dunlap wrote:
I would like to use a K&N P/N R-1380 cone shaped air filter. 4" tall,4
1/2" minor dia., 5 1/2" major dia., 2 7/16"ID flange.It flows 377 CFM is
this enough for a N/A 13B?
Lets see... air density in pounds per cubic foot is 1.325 times pressure
in inches of Mercury divided by temperature in degrees Kelvin.
Air density in pounds per cubic foot = 1.325 X (in HG)/degrees Kelvin
Temp in Kelvin equals temp in C plus 273 or about 295 for 72 degrees F
or about 22 degrees C.
At thirty inches of mercury dry air density would then be about 0.1 pound
per cubic foot. At a BSFC of 0.5 pounds of fuel per HP hour and 200 HP
or 100 pounds of fuel per hour or 1.7 pounds of fuel per minute.
With a twelve to one air fuel ratio you would need roughly
twenty pounds of air per minute or about 200 CFM.
Yes. Sounds about right. Did I make any arithmetic or other errors?
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 11:28:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 24 psi Radiator cap
Chuck Dunlap wrote:
Ed, where did you get a 24 PSI cap? the highest I could find was 16 PSI.
I start getting water bubbling from the bypass after about 8 minutes of
just idling, after water temp reaches 160 degrees. I hope a 24 PSI cap
would help, or maybe I have other problems.
Ed?
As I recall Tracy made his own by shimming the spring in the cap.
Sounds like a rotor housing water O ring leak. Perhaps an overheated
and consequently shrunk rotor housing. But then again I always look on
the dark side first as my wife Robin tells me.
Paul
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______________________________________________________
Date: Sat, 09 Jan 1999 10:37:29 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Parkman engine
Frankly with this crude and untunned intake manifold I doubt
the Parkman engine even had 78 HP.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 14:50:12 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 24 psi Radiator cap
Marvin Kaye wrote:
Chuck Dunlap wrote:
Ed, where did you get a 24 PSI cap? the highest I could find was 16 PSI.
I start getting water bubbling from the bypass after about 8 minutes of
24psi caps (and to-die-for radiators) are available from Griffin (among
others)... check them out at http://griffinrad.com/
<Marv>
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______________________________________________________
Date: Thu, 07 Jan 1999 14:52:58 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Air filters & air consumption
Brent Regan wrote:
Show off. I get 230 CFM by taking the displacement X RPM X volumetric
efficiency (1.0). Filter flow ratings are specified at a 1" H2O static
pressure drop (or 0.073" Hg). At sea level this translates to 0.25% horsepower
loss and at 10,000 feet it is 0.35 % of the available horsepower.
It gets more interesting in a turbo installation because the volumetric flow
through the filter goes up with altitude. At FL290 your volumetric flow is 3.2
times the sea level flow. In the Lancair I have two 800 CFM filters for an
engine that requires 492 CFM @ 350 Hp.
Brent
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Date: Thu, 07 Jan 1999 14:55:10 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Air filters & air consumption
Anderson Ed wrote:
Paul, my calculations using the spreadsheet gives following:
5500 RPM 225 CFM
6000 RPM 250 CFM
6500 RPM 270 CFM
7000 RPM 290 CFM
that is for a 13.5:1 Air/fuel mixture
with intake manifold efficiency of 90% and WOT on 70F day
on a cold day 15F, I get
5500 RPM 250 CFM
6000 RPM 270 CFM
6500 RPM 290 CFM
7000 RPM 315 CFM
and the resulting increasing in HP that we all notice on cold days due
to increased density of the air.
Ed
One thing we got on here is.... technical expertize in DEPTH!
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 14:57:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 24 psi Radiator cap
Anderson Ed wrote:
Chuck,
CR Racing at http://www.crracing.com/ has Stant racing radiator caps:
22-24 psi $16.00
29-31 psi $19.00
Or as Paul has suggested, Tracy has increased the capacity of a regular
radiator cap by shimming the spring.
Ed
Ask any question....... ANY QUESTION :-)
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 15:00:58 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Air filters & air consumption
Tracy Crook wrote:
I'd figure it like this:
80 CI X 6000 rpm = 480,000 CI per minute.
480,000 CI / 1728 (ci in a cubic ft) = 277.77 CFM
The rotary is capable of better than 100% volumetric efficiency (with tuned
intake) so I'd go with at least 320 cfm.
Still sounds like it would work.
Tracy Crook
Looks like your caught up moving Tracy.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 15:02:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 24 psi Radiator cap
Tracy Crook wrote:
Remember that coolant expands a lot. If the system is topped off when cold,
it is going to expel some coolant (& air if any in there ) no matter what
the pressure rating on the cap. My engine pumps about 20 ounces into the
overflow bottle from cold to hot but of course it recovers it when it cools
off.
If the engine constantly vents steam at 160 degrees then yes, start thinking
about looking for ruptured coolant jacket O-rings.
Tracy
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______________________________________________________
Date: Thu, 07 Jan 1999 14:58:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Engine pressure/temp sensors. source
Anderson Ed wrote:
Sorry, JB
I forgot that little detail. UMA is a company in Dayton,Va (yes
Virgina) that produces interestingly enough medical instrumentation and
aircraft instrumentation. I don't have their address handy, but there
toll free phone number is: 800-842-5578. I never tried to get the glass
off, but I am certain they are not "crimped" in, better quality than
bottom of the line, but cheaper than top of the line aircraft
instruments. I found the firm to provide me with good service. I would
suggest that you request their catalog of Aircraft Instruments. They
have flight instruments, engine instruments, sensors and external light
brezels all at about 1/2 price of aircraft instruments. You can get
less expensive instruments from the auto gauge places, but I believe you
would agree these are a level up from most of those.
Give them a try JB
Ed
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______________________________________________________
Date: Thu, 07 Jan 1999 16:35:29 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Air filters. Particle size.
Karl Szczypta wrote:
But isn't the K&N gauze/oil filter the worst for particle size filtering vs. foam or paper?
karl Szczypta
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______________________________________________________
Date: Thu, 07 Jan 1999 22:10:13 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Priming the oil pump.
George Moore wrote:
Ed,
I thought your post about priming the oil pump after an oil / filter
change was a really good precaution to take. I was just curious if you
removed a spark plug from each rotor in addition to disabling the
ignition, thereby eliminating any cylinder pressure on dry seals and
allowing the oil pump to spin up faster ?
Paul,
Have you given much thought to, or done any experimenting with the
various prelube systems on the market. There are versions with spring
loaded pressurized chambers and some that use small electric oil pumps
to build oil pressure before the ignition is energized. Of course they
also violate the K.I.S.S. principle !
George
I have heard of them but have no personal experience.
I would think they might be useful with an aircraft
engine that sometimes sits around for weeks without
running.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 22:31:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Air filters & air consumption
Paul Yaw wrote:
Paul wrote:
Tracy Crook wrote:
I'd figure it like this:
80 CI X 6000 rpm = 480,000 CI per minute.
480,000 CI / 1728 (ci in a cubic ft) = 277.77 CFM
The rotary is capable of better than 100% volumetric efficiency (with tuned
intake) so I'd go with at least 320 cfm.
Still sounds like it would work.
Tracy Crook
I'd figure it like that too. Plain and simple. Don't expect better
than about 90% VE unless you have a turbo, or some overlap. To make
things really simple, just figure about 1.5 cfm per horsepower. This is
not a guess, this is based on dyno testing as is the VE quote. If for
instance your engine is making 160 hp, it is using about 240cfm of air
to do so. As for the flow of the filter, it will be fine. If you wish
to mathematically determine the effect of the filter, you must know at
what pressure drop its airflow was measured. Manufacturers will say just
about anything to sell a product, and so keep in mind that airflow
numbers mean nothing without the test pressure. The fact is that with a
large enough pressure differential that filter will flow 1000cfm or
more. An earlier e-mail said that filters were measured at a pressure
drop of 1.0" H2o. For the sake of comparison, each rotor on a stock
6-port induction system (From the intake port to the throttle body)
flows 128 cfm at 25" H2o. At 1" it only flows 25.6 cfm. Yuuk! Happy
calculating.
Paul Yaw
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______________________________________________________
Date: Thu, 07 Jan 1999 22:58:26 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Static thrust & acceleration monitor
Speaking of static thrust there is a real cheap device all you
computer/electronic types out there could build.
It is an accelleration sensor made with a car ABS wheel slotted ring
and mag pickup. The trick is to interrupt the PIC microcomputer
every millisecond and disable, read, reset and re-enable an external
or internal pulse counter. This should take less than 20 microseconds.
The value in the counter is velocity. If you subtract the last velocity
from the current velocity you have a measure of the acceleration.
If you accumulate the velocity you have the distance. No need
for a distance sign along the side of the runway. You then enter
the runway length into the PIC somehow and it can warn you if
you will not be able to takeoff while you still have time to
stop. Good for short/high/hot fields.
BTW the beauty of this trick is there are no slow multiply or divide
operations required of the PIC firmware.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 23:07:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Static thrust & acceleration monitor
Also BTW I used a system like this with a 6502 for years measuring the
road performance of cars. Here is an IEEE paper I co-authored
on the system.
Microprocessor-Based System for Roll-Down and Acceleration Tests
by D.K. Lynn, C.R. Derouin, and Paul Lamar
Los Alamos Scientific Laboratory
Published in IEEE Proceedings 29th Vehicular Technology Conference
(The technical details of the Lamar Instrument road test system.)
Arlington, Illinois, March 28-30, 1979
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 23:13:47 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Wanted three rotor.
MAR34807@aol.com wrote:
Try Hayes Rotary in Redmond, Wa. That is where I bought mine.
See our NL web site for their phone number.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 23:12:17 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Pressure drop in intake system.
MAR34807@aol.com wrote:
Whatever filter you use (I use the foam Bracket filters) make sure you install
a heavy ss wire screen (not window type) behind it to keep the engine from
injesting that filter. A new Seawind I know of was lost on its maiden flight
just for this reason!
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______________________________________________________
Date: Sat, 09 Jan 1999 12:30:05 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: GS motor mount
StJames515@aol.com wrote:
Paul,
I am considering other PSRU's in addition to the Ross unit. Steve Parkman had
a 30# chain drive with a 4.5" offset to the output shaft. Others vary to a a
7-8" offset. In your view, how would the 13b fair in different mount
configurations? Also, which type: gear, belt, or chain seems best?
Tommy James
Belt and Chain get the thrust line up but none of them
have demonstrated the durabilty of the Ross/Ford C6 planetary drive.
Not that it is perfect but at least Tracy got 600 hours out
of one before overhaul.
While I was in Florida I saw Tracy's prototype version of the Ford C6
planetary unit and it looked good. He has addressed the oil
supply to the sun gear by using a plain journal bearing
and pressure from the engine oil system. That should extend
the life of the planetary gears.
Its hard to beat a planetary gear box on a weight basis.
Picture of the prototype PSRU.
Paul
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______________________________________________________
Date: Sat, 09 Jan 1999 17:15:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 13B REW twin turbo
Gordon Woodard wrote:
It looks like this would be the preferd block? Have there been any
problem areas with the twin turbo? And would twin turbos work? Im
getting ready to buy my motor and came across and deal on an 94 . I have
picked up alot of good imformation here but it seem to also bring up
more ? .
Gordon
I would not use the stock twin turbos. They were designed for throttle
Response and not durability at high continuous power levels.
The block yes the twin turbos no.
I would get an Inconel turbine from Turbonetics. Don't tell them it is
for an aircraft.
Throttle response is not as important in an airplane as it is in
a car.
They are also heavy because of extensive use of cast iron in the
exhaust manifold. Fabricate an exhaust manifold out of 0.040 or
0.050 Inconel sheet or tubing.
Paul
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______________________________________________________
Date: Sat, 09 Jan 1999 17:35:12 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Parkman
RJohn15183@aol.com wrote:
In a message dated 1/9/99 10:55:34 AM Central Standard Time,
rotaryeng@earthlink.net writes:
Yes Bill what you say is very very true. But this MUST be balanced
by some degree of reason. If Burt Rutan designed the airplane for
100 HP minimum then the FAA inspector should have a reasonable
assurance that the engine being used will indeed generate at least 100
HP and that the design gross weight of the airplane and CG location is
not exceeded by just the pilot, a little fuel and the heavier engine.
~snip~
This is giving every benifit of the doubt to the Geo engine
that it did indeed generate 78 HP.
OOPS! The varieze was *designed* to use a VW conversion NOT an O-200. *If* he
was getting 78 horses then lack of power was not the problem.
Rob
Yes. Orginally it was but Burt found out the VW did not have enough
power so he recommended at least an O-200 with 100 HP.
Klaus has his O-200 souped up and he is not a real large guy.
Never-the-less he rufuses to take anyone aloft who weighs
over about 150 pounds for safety reasons.
Tucson can be in the category of hot and high even at 8:30 AM in
the morning.
Paul
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______________________________________________________
Date: Thu, 07 Jan 1999 23:10:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Australia Rotor Craft with 13B's
Gary C. Buster LPT wrote:
Hello Colin... Glad to hear you are going to catch up with us at Bensen
Days...
SHOW ME THE PICS!!! otherwise known as... "you show me yours and I'll show
you mine!!!"
Gary Buster gbuster@ballistic.com
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Date: Thu, 07 Jan 1999 23:40:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
If you place two bathroom scales side by side underneath
each main tire with a plank between the scales you can determine the
torque the engine is generating at any RPM. You can change engine RPM at
WOT with a ground adjustable pitch prop. If you know the distance
between the wheels you know torque. Knowing torque and prop RPM you have
HP.
There will be some lift on the wing roots due to slip stream
effect so it is not a very good absolute measurement.
One wing root will be running at a higher angle of attack
than the other. Less so for a pusher than a tractor.
Tie the airplane's tail to a tree and also tie it laterally so
it does not walk off the scales.
You need four scales because bathroom scales only go up to about
300 pounds each.
Paul
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______________________________________________________
Date: Fri, 08 Jan 1999 07:12:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Priming the oil pump.
Anderson Ed wrote:
Yes, George, forgot to mention that I do remove one plug from each rotor
chamber. But, guess I was doing it for slighty different reason than
the excellent one you suggested. It is common practice on two plug
aircraft engines to remove one plug when working on them. This
minimizes the risk of any movement of the prop causing a magneto to fire
a cylinder or at least for that cylinder to have sufficient combustion
energy to spin the prop. Second reason, is to reduce the load on the
starter. In my case, with fuel injection and my oil mixed in with my
fuel (I don't use the stock oil injectors), no lubrication is provided
by the fuel since the injectors are not injecting when my ignition is
off.
Ed
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______________________________________________________
Date: Fri, 08 Jan 1999 07:17:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
CC: eaa editorial <editorial@eaa.org>
Subject: EAA awards for Tracy Crook and Everett Hatch
Paul wrote:
BTW I was thinking we ought to petition the EAA to give Everett Hatch
and Tracy Crook awards for furthering the cause of general aviation.
The way it looks now the rotary may be better and cheaper than a real
aircraft engine.
Paul
Anderson Ed wrote:
I second that motion
Ed
If any of you feel the same way send email to:
eaa editorial <editorial@eaa.org>
directly.
Paul
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______________________________________________________
Date: Fri, 08 Jan 1999 07:34:17 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Screen behind filter.
Anderson Ed wrote:
Excellent suggestion. I have SS mesh sandwiching my filter material
and then a piece of SS mesh over the throttle body throats as suspenders
(actually more to keep any bolts or nuts (or other stuff) from dropping
down the manifold when the butterflys are open. Had it happen once - a
real pain.
Ed
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______________________________________________________
Date: Fri, 08 Jan 1999 07:32:20 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Static thrust & acceleration monitor
Anderson Ed wrote:
Hey, I like the idea of a little toy car chip triggering a voice alerter
ditty during take off roll -"Hey Buddy, Your engine ain't too hot, the
accel too d___ low, better get ready to stop, 'cause I'm not about to
go". Couldn't help myself
Ed
Somehow I get the impression you are kidding Ed :-)
Just a plain yes or no would be less ambiguous :-)
All airliners have something similar these days I think.
Paul
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______________________________________________________
Date: Fri, 08 Jan 1999 08:07:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Miles per gallon
Tracy and I were sitting around talking about his new LCD
display for the EFI and the subject of miles per gallon
came up. He had intended to display GPH but with a GPS
input one could calculate what you really want to know
and that is miles per gallon.
So I promised Tracy I would send him this program.
It is written in QB 4.5 so don't laugh. QB 4.5 running
under DOS has a direct hardware access and real time
capability no other language or popular operating system
currently enjoys. This should work with any GPS on the
market that uses the NEMA 0183 protocol as most do.
SIDE BAR
Here is a short real time program that takes GPS data in from a
NEMA 0183 compatible GPS or Loran receiver and stores it on
a hard disk.
This program will not work with Windows, OS/2 or any form of UNIX.
These operating systems do not allow direct hardware access or
real time interrupts. With Linux/UNIX you can probably treat the
interface as just another ASCII terminal and redirect it to a file.
This has been tested with a Rockwell GPS receiver as used in an Arnav
panel instrument and Lowrance boat units and a Long Ranger aircraft
Loran unit. It has also been tested with a Garmin handheld aircraft
GPS.
This requires at least QuickBasic which came with DOS 5.0 or DOS 6.22
If you want it compiled you need QB 4.5 or Power Basic.
CLS 'Clear the screen
'Recieve buffer size in bytes------+
' + |
'Open buffer & wait for-+ | |
'# of stop bits-----+ | | |
'# of bits -------+ | | | |
'Parity --------+ | | | | |
'Baud ------+ | | | | | |
'Port #+ | | | | | | |
' | | | | | | | |
OPEN "COM1:4800,N,8,2,OP15000,RS,RB32000,CD0,DS0,CS0" FOR RANDOM AS #1
OPEN "NEMA.DAT" FOR APPEND AS #2
TIMER ON
ON TIMER(2) GOSUB DoIt2
' |
'Time ---+
'Two seconds is the optimum. Anything less and you lose characters.
'Anything more and you get redundant sentences.
BackGround: 'Loop! Monitor the esc key press.
IF INKEY$ = CHR$(27) THEN GOTO EndItAll 'esc key
'Check to see if the program is running.
x = x + .00001
LOCATE 22, 19: PRINT x
GOTO BackGround
DoIt2: 'Do this every 2 seconds.
TIMER STOP
CLS : LOCATE 22, 51 : PRINT "Press ESC to quit."
LOCATE 1, 1
DO WHILE NOT EOF(1) 'Do while there are characters in the buffer.
TempLine$ = INPUT$(LOC(1), #1)
PRINT TempLine$; 'Print it on the screen
PRINT #2, TIME$ 'Time stamp the file on hard disk
PRINT #2, TempLine$ 'Put the data in the file.
LOOP : TIMER ON : RETURN
EndItAll: CLS : CLOSE : SYSTEM
Here is a sample of the output data from a Long Ranger NEMA 0183 Loran;
00:06:00
$LCGLL,3031.91,N,08252.80,W
$LCBWC,,3500.00,N,12000.00,W,288,T,290,M,882.7,N,099
$LCAPA,A,A,9.85,L,N,V,A,349,M,099
$LCVTX,258,M,177,N
00:06:02
$LCGLL,3031.88,N,08252.91,W
$LCBWC,,3500.00,N,12000.00,W,288,T,290,M,882.6,N,099
$LCAPA,A,A,9.78,L,N,V,A,349,M,099
$LCVTX,258,M,177,N
00:06:04
$LCGLL,3031.82,N,08253.19,W
$LCBWC,,3500.00,N
00:06:04
,120
00:06:06
00.00,W,288,T,290,M,882.4,N,099
$LCAPA,A,A,9.58,L,N,V,A,349,M,099
$LCVTX,258,M,178,N
Here is a sample of the output data from an NEMA 0183 GPS.
This data was gathered once a second.
$GPRMC,143724.266702,V,2606.386,N,08009.915,W,0000.0,000,200493,,,*3B
18:37:11
$GPRMB,V,,,,,,,,,,,,*30
18:37:12
$GPGGA,143725.266701,2606.386,N,08009.915,W,0,0,001,,M,00043,M,,,
18:37:13
$GPGLL,2606.38,N,08009.91,W,143725.266701
18:37:14
+-time +-Valid Data
| | +-Lat +-Long +-Knots
| | | | | +-True Heading
| | | | | | +-Date
$GPRMC,143726.266701,V,2606.386,N,08009.915,W,0000.0,000,200493,,,*3A
18:37:15
$GPRMB,V,,,,,,,,,,,,*30
18:37:16
$GPGGA,143727.266700,2606.386,N,08009.915,W,0,0,001,,M,00043,M,,,
18:37:17
$GPGLL,2606.38,N,08009.91,W,143727.266700
18:37:18
$GPRMC,143728.266700,V,2606.386,N,08009.915,W,0000.0,000,200493,,,*35
18:37:19
In the $GPRMC sentence the first number is the GMT time from the
atomic clock in the sat accurate to the nearest microsecond!!!.
-The NMEA interface transmits data organized
-into sentences defined as follows:
-Sentence length is 20 bytes.
-Update rate = 1 Hz.
-Format parameters:
-Bytes are encoded as 7 bit ASCII characters in an
- 8 bit byte with the most significant bit set to zero.
-No Parity bit.
-One start bit and one stop bit.
-4800 baud.
-The total number of bits per transmitted data byte is 10.
The sentence is:
$HCHDM,
abc.d,M,*<checksumMS><checksumLS><cr><lf>
Where;
a is the BCDhundreds digit of the heading.
b is the tens digit.
c is the ones digit.
<checksumMS> is an ASCII character in the range 0-9 or A-F that
represents the most significant nibble of the checksum.
<checksumLS> represents the least significant nibble.
The checksum is calculated by XOR'ing together all the
characters in the sentence up to... but not including the
"*" character. i.e. XOR together "S", "H", "C", "H",
"D", "M", ",(comma)", "hundreds digit", "tens digit",
"ones digit", ".(decimal point)", "tenths digit", ",(comma)",
"M", ",(comma)"]
The 'header information' -- the letters before
the actual data -- tells which of the ten or so
possible types of data that NMEA0183 can transmit.
National Marine Electronics Association (NMEA)
PO Box 50040, Mobile, AL 36605
Phone: (205) 473-1793
Fax: (205) 473-1669
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______________________________________________________
Date: Fri, 08 Jan 1999 08:19:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
Rogers, Bob J. wrote:
All of us dummies would appreciate the formula to calculate torque and
horsepower using the bathroom scale method you have described. It
sounds like an elegant and inexpensive way to check the power output
of the engine and prop combination. Thanks.
There is a real simple one that escapes me at the moment. I think
it is something like 5252/torqueis HP.
Anybody remember this?
The torque is the difference in scale readings divide by the distance
between the wheels in feet.
BTW if you makes some spoiler cuffs that slip over the wing
roots the accuracy of the data would probably be improved.
Paul
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______________________________________________________
Date: Fri, 08 Jan 1999 08:52:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
Rogers, Bob J. wrote:
All of us dummies would appreciate the formula to calculate torque and
horsepower using the bathroom scale method you have described. It
sounds like an elegant and inexpensive way to check the power output
of the engine and prop combination. Thanks.
OK here it is: I forgot RPM.
Torque times RPM divided by 5252 equals HP.
(T X RPM)/5252 = HP
Paul
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______________________________________________________
Date: Fri, 08 Jan 1999 16:05:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Parkman
Ernesto Sanchez wrote:
>From a Tucson newspaper:
Flight was Stephen Parkman's first in homebuilt plane
A pilot was killed when his homebuilt aircraft crashed in the desert
shortly after takeoff from Ryan Airfield west of Tucson yesterday
morning.
It apparently war the first time Stephen Parkman, 51, had flown the
twoseater Vari-Eze. an experimental aircraft, authorities said.
The crash occurred shortly after 8:17 a.m., when the aircraft took off
from runway 6 for a local flight, said Mitch Barker, a Federal Aviation
Administration spokesman in Seattle.
Parkman soon alerted the control tower at Ryan Airfield that he was
experiencing problems. He was cleared to return to land, Pima County
Sheriffs Lt. Oscar Miranda said.
Investigators have not determined what caused the crash.
"The pilot radioed he was 100 feet off the ground and then they lost
radio contact." Miranda said.
The aircraft caught fire on impact in the desert less than a
quarter-mile north of the 7600 block of West Valencia Road. The
wreckage was strewn about 100 yards among mesquite trees and chollas.
A pilot who was about two miles north of the airport when Parkman
radioed his distress call circled the area and found the wreckage about
three miles east of the airport following a thick black column of
smoke. That pilot, an off7duty Department of Public Safety officer,
directed rescue crews to the wreckage.
Parkman's family could not he reached for comment yesterday. According
to friends, his son had recently Left for boot camp with plans to
eventually become Navy pilot.
The National Transportation Safety Board and the Pima County Sheriffs
Department were investigating the crash. Investigators, who spent most
of the day at the site, were researching the specification of the
aircraft
An FAA incident report noted that it was the aircraft's initial flight.
Parkman's exact destination was unknown because only commercial aircraft
are required to file flight plans
The door to Parkman's hanger remained open a few hours the Crash, wrth
his Rambler station wagon, bearing a 'Fly Navy" bumper sticker, parked
out front Another one of Parkman's homebuilt aircraft, a World I
replica - could be seen in his hangar.
Word of the crash spread quickly at Ryan Airfield, where Parkman and his
aircraft were familiar sights. Some pilots had heard Parkman's radio
exchange with the control tower.
Many pilots expressed sadness but most did not want their names
published.
"Usually we lose our pilots to old age or sickness - It's a rarity to
have someone get killed," said pilot Henry LaCoree.
The general public may have been unfamiliar with experimental aircraft
until singer John Denver crashed in a privately built Long-EZE, a larger
version of the plane Parkman was flying. The October 1997 wreck remains
under investigation.
Authorities called the aircraft safe.
"Its like any other airplane, if it is properly built, properly
maintained and properly flown, it's just as safe as any other plane,"
Barker said.
He may not have known it had a Geo engine. If I were the FAA inspector I
would not have signed off on it.
Paul
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______________________________________________________
Date: Fri, 08 Jan 1999 16:08:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
Brent Regan wrote:
Guys! Geezz. When you bolt a prop on backwards you will still go forward. It is
an air screw, remember. Also the two place Lancairs have stub wings with the
gear that don't come off.
Brent
But not as well :-) So there is less slip stream and more corkscrew
for the same HP consumption :-)
Paul
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______________________________________________________
Date: Fri, 08 Jan 1999 17:33:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: John Larsen <jopatco@cyberhighway.net>
CC: Dave Martin <dave@kitplanes.com>
Subject: Feb. Kitplanes Engine Beat column.
I am sorry to inform you John that the two rotor Wankel
engine has only two power pulses per revolution rather
than three as stated in your Feb Engine Beat column.
If you are talking about a one rotor it obviously
only has one power pulse per revolution.
I wish it were so but unfortionately it is not.
BTW Tracy Crook recently discovered that the Mazda rotary
could and will run 100 degrees lean of peak somewhat reducing
the BSFC well below 0.50
Paul Lamar
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______________________________________________________
Date: Fri, 08 Jan 1999 19:01:22 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: new rx7-4th gen?
MAR34807@aol.com wrote:
On page 33 of Car & Driver's Feb. 1999 edition:
"RX-7 will return: Mazda executives now say it's a matter of when, not
if, a sporty car called the RX-7 will return to the U.S. market. Our
first look will likely be at the Tokyo show later this year, with
production to begin in 2000. The best bet is that it will have a rotary
engine (although the Miller cycle motor, similar to the one in the
Millenia, is a long shot) and will be built on a stretched version of
the Miata platform. It won't be as exotic or fast as the late, lamented
third-generation RX-7 that slipped from these shores a few years ago,
but it will be less expensive."
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______________________________________________________
Date: Fri, 08 Jan 1999 21:03:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ross PSRU-bellhousing?
MAR34807@aol.com wrote:
A question; If one uses the Ross PSRU, does one also have to get a auto tranny
bellhousing to bolt it to, or is something else used? Will the manual tranny
bellhousing work? I know the counterweight/ring gear needs to be the auto
spec......
The Ross comes with a bell housing now.
It is not necessary to obtain a Mazda bell housing.
Paul
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______________________________________________________
Date: Fri, 8 Jan 1999 23:32:24 -0500
From: jpr@ix.netcom.com
Subject: Re: REFLECTOR: Re: [c-a] Lightning strike
To: reflector@awpi.com, Dave Black <asterisk@EROLS.COM>
CC: "Andrew L. Judge" <AJudge1@Compuserve.com>,
"Aviators .Canard" <canard-aviators@canard.com>
[The Canard Aviators's Mailing list]
Oddly enough, I saw the results of a lightning strike in almost the
exact same circumstance - but as strange as it may seem, it struck the
Velocity at the middle rudder hinge while it was parked on the ramp
between several metal airplanes, which apparently were not hit (at
least, not damaged).
The lightning reportedly arced over from the hinge to one of the
antennas, exploding the rudder off the winglet and boiling the foam
enough to completely distort the entire winglet (I do have pictures).
After traveling down the antenna lead, it went to the rudder cable and
traveled down that until it hit the aileron counterweight and voided a
bit of foam there. The rudder was thrown off the airplane, and the
rudder return spring was stretched out straight.
The radios were completely zapped, and magnetized all the steel in the
engine, including the engine mount.
I agree, if it had occurred in flight, not much would be known about
it... however, I'm not sure if being struck in the air is as likely
(or more likely, or less likely) than being struck on the ground. I
know that plastic airplanes can accumulate more charge than a metal
airplane, but where would the lightning go from there? On the ground,
of course, it arcs over to ground. In the air would it 'arc over' to
another cloud or something?
As for why it did not strike the other, metal airplanes, who knows?
Perhaps the plastic plane had built up a charge that was more attractive
than the actual ground (would that be positive or negative - I forget..)
Anyway, lightning in the air is not good for any plane, and I recall
hearing of someone that this happened to who luckily survived - and I
think it was in a plastic plane.. I can't remember where I read it..
So, I guess the best thing to do is to stay away from areas of
lightning, as much as it can be predicted!
I wonder if the Glasair or Lancair or whomever is installing the
aluminum fiber mat, has really tested what a "typical" lightning bolt
can do to it.. Seeing the results of this, I really wonder if it would
possibly be worse (blow the skin off??)
-john rourke
Dave Black wrote:
Andy,
I had a bolt of lightning hit my plane while it was on the ramp.
1) Glass planes are NO MORE attractive to lightning than metal ones.
2) Lightning strikes on glass planes causes MUCH MORE damage than to a metal
one.
Dave Black
Velocity RG
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For details on sponsors of this list, copyrights, and how to remove
yourself from this list, please visit:
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______________________________________________________
Date: Fri, 08 Jan 1999 21:19:41 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Feb. Kitplanes Engine Beat column.
Carl wrote:
Now hold on. I thought the 2 rotor had 6 power pulses per revolution and
the single had 3 per revolution. What am I missing here?
Three sides per rotor, three sparks per revolution. ??
Yes for the rotor rotation but no for the output shaft.
The rotor runs at 1/3 the revs of the output shaft.
Carl
To invent an airplane is nothing.
To build one is something.
To fly, is everything.
-- Otto Leinthal 1848-1896
One spark (2 for dual plugs) per output shaft rev per rotor.
To further confuse the issue the rotor rotates at 1/3 the output
shaft speed. Amazing is it not?
Check the last web site link on the NL web site. There is a nice
animation on there.
Paul
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______________________________________________________
Date: Fri, 08 Jan 1999 21:44:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: % power indicator, look at this company
marc wrote:
This company seeks new engine/instrument display ideas, and it seems this
group could give them some. My only problem with the instrument is that it
does not take EGT/TIT or actual fuel flow into account for LOP operation. I
guess % power is approximated from a programmed table using RPM and MP as
well as temp.
Anyhow take a look, and contact them on your ideas!
http://www.technologykitchen.com/index.htm
--
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______________________________________________________
Date: Fri, 08 Jan 1999 21:48:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Rotary engine rebuild tape
marc wrote:
BTW: Does anyone know who was selling the rotary engine rebuild tape? Has
anyone bought a copy yet or received it?
Since I spoke with the list, I have had a discussion with Bruce. He is a
voc ed teacher, works part time rebuilding rotories for a firm (Jemco, I
think he said?). Tape focuses on problem areas, and mostly the late madel
13B engine. He seems very on the up and up. Told me that the set has an
integral powerpoint presentation in the tape set! As he does all his own
tape duplicating, he is a little behind (his dup unit broke down), has
orders for 30 right now. Told me to expect my tape next week! can't wait to
see it as I have an 89 13B torn down in the garage right now awaiting
assembly!
If anyone has seen it by now, please let's hear your comments!
Here you go:
"4 hour, two tape set, (Bruce refused to accept the video quality loss
when using extended play recording) covers all the details of disassembly,
cleaning, wear evaluation and overhauling the 13B core. Highly
Recommended.
Send your orders along with a check for $29.95 to :
Bruce Turrentine
5337 Trestlewood Lane
Raleighg, NC 27610"
Note: this tape is the one I asked about interest on the list much
earlier..........
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______________________________________________________
Date: Sat, 09 Jan 1999 08:53:58 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
TERF Email wrote:
Hi Paul
Nobody has mentioned this technique so I thought I would pitch in. As
you will recall we had that jet engine dyno test stand at Oshkosh last year.
I built a "load cell" unit for that out of a small (approx. 1" ID) hydraulic
cylinder and a oil pressure gauge. Measure the inside surface area and
convert from psi linear force to psi hydraulic pressure and you are home
free.
You might even use an electronic sending unit so that you can read the
gauge in the cockpit w/o a long hose on your gauge. A little creativity in
the voltage conversion and the gauge will even read right. For the
mechanical gauge I screwed the face off (ok it was a pretty nice gauge) and
laid out a new face on CAD and placed it behind the needle to get that "OEM"
look. (Bigger gauges are nicer.) A lookup table is good if you don't mind
the trouble / delay in the conversion process.
This is a nice solution because there is nothing moving or stretching.
It is fairly easy to get an inexpensive cylinder that is small enough to
keep the "stick friction" from being a problem (especially since the piston
doesn't really move much) and strong enough to keep your airplane from .....
shall we say ..... going on its merry way. Remember to size the cylinder
and gauge for the correct resolution. Many engine and brake test
dynamometers actually use this method because it is hard to break under
pounding and tugging vibrations. Strain gauges and quartz sensors are
expensive and fragile.
The one we have built has several hours at about 200# thrust in test and
development of the jet engine. It came out within about 2% or so in
accuracy from the calculated gauge face. We merely slid the laminated paper
around slightly in the gauge to get the offset calibration correct. Double
face scotch tape works great to hold it in place.
P.s. A bleeder valve is nice too... gotta get the air out obviously.
Don't forget to subtract the area of the shaft if you use that side of the
cylinder. Calibration can be done by hanging a weight from it like a fish.
Best Regards & Hope that this helps Matthew Tait
Good ideas Matt. If you have a drawing of the cyl incorporated into
a rubber engine mount similar to the Qestair design please send it to
my FAX number (310) 475 5517 before 8 AM your time if you can. My FAX
and modem line are one and the same.
Paul
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______________________________________________________
Date: Sat, 09 Jan 1999 09:00:40 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: New rx7-4th gen?
David Morris wrote:
For those interested in seeing pic's of the last version of the 3rd
generation (known as the series VIII), check out the DMRH site at the
below URL.
http://www.3rotor.com/dmrh
REgards
Dave Morris
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______________________________________________________
Date: Sat, 09 Jan 1999 08:59:07 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 3-rotor parts]
David Morris wrote:
G'day guys.
On the subject of 20B parts.
They are available "new" from Mazda but the bad news is there's no
eccentric shafts left. (thats the common problem with their
unreliability).
Thats interesting. What sort of problems are they having with the
shafts?
A contact at Mazdaspeed (Japan) said that demand is
getting stronger for them & they feel Mazda will do a new production run
of shafts in the near future.
However they will still have the inherent (flexing) problem. I have
heard of a NZ engineering firm making 3 rotor shaft for the 20B that are
of a higher quality steel. I'd suggest that if someone wanted to build
up a 3rotor from parts, they use the NZ built shafts instead of the
Mazda ones.
I'll endevour to find the contact details for the NZ company in the next
few days.
REgards
Dave Morris..................DMRH special vehicles
http://www.3rotor.com/dmrh
That's encouraging. I was hoping someone would start to make Mazda
engine parts.
Paul
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______________________________________________________
Date: Sat, 09 Jan 1999 09:48:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Parkman
Bill Freeman wrote:
Paul, Paul, Paul,
We normally agree on most things, but I must object strenuously
to your comment about the Vari-Eze that (apparently) had a Geo
engine and crashed. Please think a moment about the implications
of what you just said! If any FAA inspector could decide what
was and what wasn't a "suitable" engine for a homebuilt, do you
think most would sign off on ANY auto engine, ESPECIALLY some
wierd engine that has no pistons and runs on some strange principle
the he doesn't really understand is NOT LIKE any other engine -
i.e. a rotary. Remember, freedom means the freedom to succeed and
MUST implicitly include the freedom to fail, which sometime can
be fatal. If failure is precluded by the gov't, all freedom is gone.
We need to hang together and keep an open mind about new ideas.
I probably agree that a Geo motor may be a poor choice for an
aircraft engine, and God knows if there is ANY airframe more
unsuited for an "iffy" engine than the Vari Eze, I can't think of it
right now. New engine testing should take place in Kitfoxes or
J3s or similar low landing speed AC.
Take care, and sorry to hear about your giant travel
debacle. Been there, done that. :-0
Bill
Yes Bill what you say is very very true. But this MUST be balanced
by some degree of reason. If Burt Rutan designed the airplane for
100 HP minimum then the FAA inspector should have a reasonable
assurance that the engine being used will indeed generate at least 100
HP and that the design gross weight of the airplane and CG location is
not exceeded by just the pilot, a little fuel and the heavier engine.
A poor choice of engine resulting in a fatal crash hurts the
experimental movement as much as excess oversite would.
This is giving every benifit of the doubt to the Geo engine
that it did indeed generate 78 HP. Steve never claimed it had
more HP than that.
Perhaps what we need is better qualified FAA inspectors. Maybe
one or two non AC engine experienced inspectors that can
fly around the country and inspect non AC engined experimental
aircraft.
The picture is of Steve's airplane.
Paul
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______________________________________________________
Date: Sat, 09 Jan 1999 23:03:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Parkman
Rodger Hilyard wrote:
Paul what a can of worms your are suggesting......
When we build an aircraft,and the FAA inspects it,do you want them
to require a certified report from some approved testing lab that your
as intsalled engine provides a certain horse power with a specific
propeller?? What happens when your 0-200 only puts out 98 HP?
what if it puts out 110 HP,after all it doesn't comply with the designers
suggested 100HP.....What if you produce an engine that DOES make
100HP but at 19zillion rpm,is that OK?
At this point we dont know,and may never know what caused are fellow
experimenter Steve Parkman's tragedy.It may well prove out that running
an automobile engine at power levels twice there original supplied HP
IS an unreliable way to do things.
For your consideration...Rodger Hilyard
We do know the airplane refused to climb normally.
I will garantee that running an auto piston engine at twice its
orginal power levels continuously is an unreliable way to do
things. We have one hundread years and billions of auto piston engines
to prove it. The actual RPM it generates its power has only somewhat to
do with it.
The Wankel rotary is showing a lot of evidense, from auto racing and now
from use in aircraft, that it can take a least its rated power
for long periods of time.
Of course its an inexact science. Only gross violations should be
refused.
IMHO this one was a gross violation of accepted engineering principles.
Paul
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______________________________________________________
Date: Sat, 09 Jan 1999 23:27:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 13B/20B turbos?
MAR34807@aol.com wrote:
In a message dated 99-01-09 19:23:15 EST, you write:
<< I would get an Inconel turbine from Turbonetics. Don't tell them it is
for an aircraft.
Paul, which one would you pick for a 20B? In a normalized mode, which one
would give best performance at altitude? Alternatively, how about one for a
13B?
I'm not sure exactly how to pick one given all the variations available!
We kind of have a secret code with Turbonetics. If you tell the engineer
you are building a two or three rotor Pikes Peak racing car and you want x
amount of power at 14,000 feet he will make recommendations.
Also contact Chuck Harbert who has been there and done that.
chuck_harbert@arkwright.com
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______________________________________________________
Date: Sat, 09 Jan 1999 23:35:59 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 13B REW twin turbo-reliability?
MAR34807@aol.com wrote:
Gordon Woodard wrote:
It looks like this would be the preferd block? Have there been any
problem areas with the twin turbo? And would twin turbos work? Im
getting ready to buy my motor and came across and deal on an 94 . I have
picked up alot of good imformation here but it seem to also bring up
more ? .
Many (not all) of these engines suffer some sort of distress prior to 100,000
miles-could be the very low oil electonic injection rate, the intense heat of
the turbo engine, turbo manifold cracking, worn turbos, overboost leading to
apex seal failure and housing damage, or the very susceptible coolant system
(prone to failure, which overheats many engines, I''ve got experience with
this). I''ve got two 13Brew engines sitting in my garage right now, both
running (in 94 rx7s)! They are essentially the 13B 91 turbo engine with a few
mods and different turbos/computer. And the intercooler is way too
small.........
Check the compression on the engine and rotate it for sure before you buy it!
Hopefully you will not use any of these stock accessories in an aircraft.
Apex seal lube oil (2 cycle oil) is best mixed with the gas. Low oil quantity apex seal
injection rate was done primarily for smog reasons.
However a lot of these issues have been addressed in the very latest RX7
introduced in Japan just a few weeks ago.
Paul
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______________________________________________________
Date: Sat, 09 Jan 1999 23:49:59 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: hp of 13B unverified in stock cars?
MAR34807@aol.com wrote:
86-88 na 145hp
86-88 T2 185hp
89-91 na 165hp
89-91 T2 200hp
Thanks for the list.
Many of the NA HP differences are due to minor porting differences
and intake and exhaust tuning.
There is very little internal differences in the engines themselves.
See the desertation on the NL web site for some of those
differences.
I do recommend paying detailed attention to intake and exhaust
tuning for NA engines.
Make sure the engine will rev to at
least 6000 RPM in the climb mode by carefully chooseing the right
prop. With proper intake/exhaust tuning the HP curve around
6000 RPM is a stright line so small differences in increased
RPM make large differences in increased HP.
Get Tracy's book for a start on the prop pitch/size and other details.
rws@altavista.net
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 01:13:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 13B REW twin turbo
David Morris wrote:
G'day from DMRH.
The problem with the factory Hitachi HT-12 twin turbo's are their shaft
length. For the size of the turbo it's shaft is quite long & this
effects their reliability as the shafts start to go through their seals.
For automotive applications the maximum boost for the HT-12's should be
15 psi. Even at this level, their reliability is compromised.
For aircraft use you won't find too many people recomending you stick with
the Hitachi's.
REgards
David Morris
http://www.3rotor.com/dmrh
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______________________________________________________
Date: Sun, 10 Jan 1999 12:10:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 13B REW twin turbo OK?
MAR34807@aol.com wrote:
Also--------
First thing to do is to do a compression check.
Or remove one sparkplug and listen to escaping gas sound, should have 3
whooshing sounds per rotation of rotor. Do this separately for each rotor.
It may have a damaged apex seal.
Check out http://www.gate.net/~mrmazda/cfaqtext.html and look at "How do I
know if my engine's apex seals are OK?"
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______________________________________________________
Date: Sun, 10 Jan 1999 12:20:30 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Miles per gallon
Tracy Crook wrote:
Paul wrote:
Tracy and I were sitting around talking about his new LCD
display for the EFI and the subject of miles per gallon
came up. He had intended to display GPH but with a GPS
input one could calculate what you really want to know
and that is miles per gallon.
Thanks for the tip on the available data in the GPS stream Paul. I'll have
to write an assembly language version of the basic program but that helps
get me get going down the right path. I always wanted an MPG display so
will definitely add it to the instrument.
Tracy Crook
While I have you on the line here do any of the new PIC models
have 16 bit pulse counters? My PIC books are temporarily up
at the hangar.
I am thinking of building a takeoff acceleration monitor
using a slotted ring and mag pickup from a junk yard
auto ABS system. You would not consider adding that to your
display system would you? :-) Your PIC need not start monitoring
the engine untill the airplane was off the ground :-)
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 12:49:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Take off acceleration monitor.
Opps here it is in the Digi-Key catalog.
17C756/CL-ND EPROM $20.60 qyt. one. Page 145.
68 pin CLCC.
I believe in overkill with microcomputers.
You never can tell when you are going to need
a new feature. It has 50 I/O pins
16K by 16 EPROM 902 bytes RAM DC-33MHZ
Timer 3 is a 16 bit timer/counter. Can that be incremented
externally?
This would drive LED's directly.
Which one are you planning on using?
HP has some real nice 4 digit
dot matrix very readable avionics type displays. Rather expensive
however at about $50 each as I recall.
I would use one of these for incrementing the runway length
in feet with an up/down toggle switch.
What are you going to use for your display?
For the acceleration monitor output a loud horn/klaxon/bright
light or as Ed suggested, a voice chip.
You could of course kill the engine and apply the brakes
automatically. Maybe not :-)
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 13:12:26 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Climb
I got to thinking about climb and came up with what
I thought was a simple way of looking at it.
The orginal definition of HP was how fast a horse could
lift X amount of weight X amount of distance in X amount of
time.
The number was 550 pounds... one foot... in one second.
If you have an airplane with a gross weight of 1500
pounds and you have 25 HP left over after you subtract
the HP required to keep it flying at a fixed altitude
you should be able to calculate the potential rate of climb.
Let's see... 550 pound divided by 1500 pounds gross
is 0.37 feet per second up.... per HP.
Times 25 HP is 9 feet per second or
540 feet per minute. About right.
Feet per minute is what is displayed on most
aircraft rate of climb steam gages.
If it took 75 HP to fly the airplane
and you had 100 in the engine you would climb at
about 540 feet per minute.
If the engine was only developing 75 HP you would not
be able to climb.
This is a crude aproximation. I think the drag of the airplane
goes up due to the additional lift required to climb and hence
so does the "CL^2 / pi X Aspect Ratio" induced drag factor so this
calculation is probably optimistic.
In other words its worse than this.
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 08:40:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: New RX7 details.
MAR34807@aol.com wrote:
In a message dated 99-01-10 01:42:46 EST, you write:
However a lot of these issues have been addressed in the very latest RX7
introduced in Japan just a few weeks ago.
Paul, where did you find the info on the latest 3rd gen 99 model on the
engine? I have not heard about this and would like to find out what has
actually been done to the engine! I do know it is NOT the MSPRE engine (yet)
in those Japanese spec 99s. Some airflow characteristics were changed (new
front end) and some accessories, but nothing major.............
>From this web site.
http://www.e.mazda.co.jp/Publicity/Public/9812/981215be.html
Here is part of the press release.
December 15, 1998
The New Mazda RX-7 Powered by 280 PS Rotary Engine
- a pure sports car improved its "Fun to Drive" -
Mazda Motor Corporation today announced the long-awaited arrival of
the new RX-7. Mazda's modern version of a pure sports car will be
available beginning January 21 next year through Mazda Anfini dealers
throughout Japan.
The RX-7 has a legendary tradition for offering driving enthusiasts
the greatest "fun to drive" character. Building on that reputation, the
new RX-7 turns heads with its powerful, unique exterior, and Mazda's
compact, lightweight, and high-powered rotary engine.
The main features of the new RX-7 are:
1) Enhanced turbocharger efficiency and cooling performance that afford
increased maximum engine power of 280PS (JIS net) for both the Type RS
and Type R. models
-Higher engine power and the new RX-7's light weight achieve a
power-to-weight ratio of 4.57 kg/PS for the Type RS model.
Despite the enhanced driving performance and new equipment, the price
for the 280 PS top-of the line models barely increases. The 5-speed
manual transmission, type RB, with a maximum 265PS engine output costs
2,898,000 yen (one price nationwide), making the new RX-7 more
affordable than ever.
The monthly sales target is 500 units.
Highlights
1. IMPROVED DRIVING PERFORMANCE
Enhanced turbocharger efficiency and cooling performance due to
increased air-intake allows the new RX-7 to achieve a maximum output of
280 PS/6,500 rpm (Type RS, Type R) increased engine power combined with
the light weight of the type R model realizes a power-to-weight ratio of 4.5 kg/PS.
Along with greater output at high engine speeds and an extended top
end, the torque at medium engine speeds has been increased for better
acceleration. Specific changes that have improved engine performance
include:
* The use of abradable seals and increased air flow provided by an
ultra-high-flow turbine achieves a turbocharger pressure approximately
1.2 times previous models.
* Modifications to the internal structure of the main silencer have
reduced exhaust pressure, contributing to lower resistance.
* In addition to increasing the aperture surface area of the
air-intake, including the radiator and intercooler.
* The air cleaner uses a separate air duct that allows air to pass
over the vehicle for more efficient cooling.
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______________________________________________________
Date: Mon, 11 Jan 1999 08:51:59 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Parkman
Anderson Ed wrote:
Paul,
I must agree with the comments of Bill Freeman. First, the FAA
inspection - as I was told many times during my building process - only
makes you legal, it does not make you safe (although a good
knowledgeable, dedicate inspector is certainly a benefit). I eventually
had to retain the services of a DAR (Designated Airworthiness
Represenative) do my inspection because the local FAA inspector (nice
Gent) did not feel comfortable inspecting an aircraft with a Mazda
engine. In fact, he orginally sent my package to the FAA maintenance
division - because "they have engineers there". It took 3 months to
finally get my package back with no one willing to take action on it.
I believe that responsibility for a safe aircraft/engine must and
should reside with the builder. Bureaucrats and institutions are
inherently conservative (no value judgment here) and for the most part
resistant to change - why else did certification of an aircraft/engine
cost so much in the past.
I don't think any system is going to change human nature. We all from
time to time tend to ignore facts when they contrast with our beliefs or
even wishes. The principal things is DO YOU TRULY UNDERSTAND THE RISK
and are you willing to deal with the facts rather than perhaps
optimistic hoping things will work. Each person perceives and deals
with risk differently, you can - with diligence, good advice from others
and willingness to listen and consider the cautions of others, minimize
the risk - but, can never eliminate it totally.
As you know, Paul, some folks assume that everything will work out all
right and other folks assume that anything that can - will fail.
I think the only prudent approach is to assume that anything that can
fail will fail and design fail safe/ redundancy/ recover actions for
critical items - where feasible. And THEN ask yourself, what are the
chances it will still fail and what are the final risk if it does.
There was no mention in the report of Steve having a ground crew
standing by and certainly not implying it would have made any difference
in this case. But, I strongly urge anybody for their maiden flight to
have 2-3 folks with fire extinguishers, crash axes, and radios in four
wheel drive vehicles off each end of the runway. Hope for the best, but
plan for the worst.
Ed Anderson
Some folks will convince themselves
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______________________________________________________
Date: Mon, 11 Jan 1999 10:05:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Climb
Anderson Ed wrote:
Paul, thought I would throw in some "real" world data. I have made one
time to climb data collection with the following results:
15F day with RV-6 Weighing 1600 lbs
at 3000 MSL 1450 fpm
at 5000 MSL 1230 fpm
at 7000 MSL 1000 fpm
I estimate based on the comparison of this data with designers data that
engine is producing approx 150hp. I have a 68x72 prop and can reach a
static rpm of 5000-5200 depending on ambient air temp. Aircraft does
climb well at 120 IAS at 5800 rpm, but will hopefully do better now that
I have removed the 2" of foam I had in my air intake. Several folks
have suggested that 2" of foam in the 3" dia duct was unduely
restricting airflow resulting in the 2" lower than expected manifold
pressure. A gain of 10-15 more hp will give me what I have targetted
for performance. I currently can only get 6000 rpm when level flight,
but believe that will improve with tweaks to timing and fuel injection.
Ed Anderson
Obviously you have a lot more than 25 HP left over :-)
I think your prop is still a couple of inches too long and/or you need
better intake and exhaust tuning.
The HP should still be strongly increasing in the 6000 to 7000 RPM
range.
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 15:57:54 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Climb
Brent Regan wrote:
So then if you shut off the engine, stopped the prop and and descended to
maintain cruse speed (in cruse configuration) you can calculate cruse
horsepower from the aircraft weight and rate of descent. Right?
Brent
The HP numbers mentioned are net out of the prop. Not the HP of the engine
let alone through the prop and PSRU.
In theory yes.. I would guess but I might want to think about that
for awhile :-)
The proplem with stopping the prop or even letting it windmill is... it adds
drag to make the airplane decend faster than it would if the prop merely
fell or flew off. (Assuming that did not put the CG too far aft).
The CAFE came up with an idea to make the prop net zero drag by
measuring or detecting crankshaft end play.
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 20:09:48 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Getting your airplane signed off by the FAA
Perry Mick wrote:
Anderson Ed wrote:
Paul,
I must agree with the comments of Bill Freeman. First, the FAA
inspection - as I was told many times during my building process - only
makes you legal, it does not make you safe (although a good
knowledgeable, dedicate inspector is certainly a benefit). I eventually
had to retain the services of a DAR (Designated Airworthiness
Represenative) do my inspection because the local FAA inspector (nice
Gent) did not feel comfortable inspecting an aircraft with a Mazda
engine. In fact, he orginally sent my package to the FAA maintenance
division - because "they have engineers there". It took 3 months to
finally get my package back with no one willing to take action on it.
It looks like they're playing the same game with me. I sent my
paperwork to the local Portland OR FSDO in early December. After a few
days the airworthiness inspector sent me email saying he sent my file to
the MIDO office in Seattle. I left a message on his phonemail, he
didn't call back. Sent email to the guy at the MIDO office, he hasn't
responded. So now I just decided to sit back and see how long it takes
these bureaucrats to come back with some type of response.
Guess I'd better find out who the local DAR's are.
Perry J. Mick
Mazda 13B-powered LongEz N7XR
Makes you wonder what we are paying these guys for.
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 21:29:24 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: How about a "certified engine" test??????]
MAR34807@aol.com wrote:
Information to chew on seen on another list..........
It was said ..."I was told by their engineers that any
production aircraft engine has to go to TBO and 100%
power in order to meet certification requirements."
This is common folklore but has no basis in reality or
truth. One must be very careful when talking to
engineers. There is only one "bible" used in the engine
test cell, read on...
The document that governs any certification of any
aircraft engine (be it reciprocating piston engines or
turbine) is Advisory Circular AC33-2B, "AIRCRAFT ENGINE
TYPE CERTIFICATION HANDBOOK".
To cut to the chase; only 150 hours are required to
certify ANY aircraft engine! And so as not to bore y'all
I'll give you the pertinent sections (brutally and
severely edited). Every combination you can think of is
covered in the manual. Single-speed supercharged,
double-speed supercharged, turbocharged, gear driven,
helicopter engines, etc. are all covered in the manual.
Prop, accessories and other good stuff are all addressed
in testing.
Section 33.49 Endurance Test
a.) General...during the runs at rated takeoff power and
for at least 35 hours at rated maximum continuos power,
one cylinder, must be...not less than limiting temp, the
other cylinders must be operated at not less than 50 deg
below the limiting temp...
b.) Unsupercharged engines. . . (1) 30 hr run...alternate
periods of 5 minutes rated take off power...5 min best
economy (2) 20 hr...alternate periods 1.5 hr @max...1/2
hr @ 75%&91% (3) 20 hr...alternate periods 1.5 hr
@max...1/2 hr @ 70%&89% (4) 20 hr...alternate periods 1.5
hr @max...1/2 hr @ 65%&87% (5) 20 hr...alternate periods
1.5 hr @max...1/2 hr @ 60%&84.5% (6) 20 hr...alternate
periods 1.5 hr @max...1/2 hr @ 50%&79.5% (7) 20
hr...alternate periods 2.5 hr @max...2 1/2 hrs max best
economy...
c.) Gear driven engines...etc. (you get the idea...)
AC33-2B is more than 115 (double sided) pages. Make no
mistake, the FAA required testing in the manual is
severe. And of course, if any one of the tests failed it
would have to be repeated. Yes, an engine could have
thousands of hours on it during development, or in
preparation for the certification test. But, bottom line,
a certified engine only has to pass 150 hours of testing.
What I have listed above is a gross simplification of
what is required. For those that are interested in such
things you should get a copy...it makes for fascinating
reading!
BTW, TBO is a manufacturer's term. It has nothing to do
with Certification or AC33-2b.<<
--
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______________________________________________________
Date: Tue, 12 Jan 1999 07:01:59 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Getting your airplane signed off by the FAA
Anderson Ed wrote:
Perry, hope you don't have to "hound" them to return your package as I
did. They were not unfriendly, just appeared to be busy with "higher"
priority things. However, if you just wait for your package to be returned
- I suggest you don't hold your breath for that period of time.{:>}.
Ed
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______________________________________________________
Date: Tue, 12 Jan 1999 18:23:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Parkman-comments on the homebuilder movement
RJohn15183@aol.com wrote:
In a message dated 1/12/99 5:50:39 PM Central Standard Time,
rotaryeng@earthlink.net writes:
That being said, I know individual(s) who were either crazy or stupid
enough to go ahead blindly even after being given constructive advice from
genuinely knowledgeable EAA members, including some who looked at the
assembly of parts and said 'You will certainly kill yourself unless you do
such and such',
This is a bit of a sore point for me. Which "knowledgeable" person? Which
"expert"?
History books are absolutely chock full of highly educated experts who simply
could not "think outside the box." Every single new product ever made has had
some "expert" who said it would not work. For every Jeff Spitzer, there are a
hundred degree'd engineers that will tell you the rotary won't work in a
plane.
Ask Tracy Crook how many "experts" STILL tell him he is crazy even after the
hundreds and hundreds of hours he has on his machine.
Here's a good example. Two years ago, well before this newsletter got started,
Paul told Jim Mederer about my plans for the 20B. Jim told Paul that a 20B
would never stand up to aircraft use. Now he is building one.
Can you document that Rob? :-) I will see Jim shortly. As I recall
it was the rotary engine in general and not the 20B specifically and
you, as I recall, were not involved. This was well after Jim built up
an aircraft engine and had it displayed at Oskosh. So he is nothing
if not consistent.
That's nothing! I told him his first 3rd gen RX 7 land speed record car
would crash at Bonnevile and it did :-) Don Sherman and Csaba Csere were there
and heard me tell him. He told me after the 238 MPH crash... that "I did not know
it all!" :-) We are still friends. Sometimes even the best of us are blind.
Which time do you believe this expert?
Should I have just shrugged my shoulders and gave up
on the project because that expert on rotaries (and he is! No doubt about it!)
said I could not do it?
Hmmm, on that note, in light of Parkman's extensive experience with auto
conversions. HE WAS an expert. Was he right? Did he screw up? Do we even know
what caused this crash yet?
Parkman was an expert in assembly langauge programming of engine computers.
I asked him at his talk at the Copperstate fly in what the BSFC of his engine was
and he told me (as I recall) 0.28. Wrong! We had a little go around about
it. He was not strong in other related areas.
Aren't all you Parkman bashers gonna feel real stupid if something like a
broken AN fitting (aircraft quality) caused this crash?
Yes. But probaly not. If the AN fitting broke it was probably not
properly supported. One of Steves engines had twisted safety wire holding
the fuel injectors in the intake manifold. The picture is below
and was taken at the last Copperstate fly in.
In the space program, we had the best of the best at work in all phases of the
project. How many rockets blew up before they got it right? And every time a
rocket blew, there was some "expert" talking about how crazy NASA was to even
try.
I'll tell you Rob I don't buy it. You will always find at least one nay-sayer
on any subject. That does not mean you are allowed to ignore Newtonian
physical principles. They are not just a good idea.... they are the LAW.
If one allows oneself to start thinking like this one is in danger
of ignoring a century of hard won aviation experience.
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 15:45:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
TERF Email wrote:
I didn't really draw up any pictures of the design. It is just a
hydraulic cylinder w/ a gauge attached. It can be anchored to a tie down
(a really good one) and the craft to test the aircraft's net static thrust.
Or, as you mentioned, a cleverly designed engine mount with a fulcrum would
give you real time data all while you are flying, taxiing whatever. A
safety catch would be necessary so a leak in the cylinder wouldn't result in
a significant movement of the engine. Probably just using a very short
cylinder would work fine. Now you have a way to confirm your net thrust /
power output. Makes one less likely to "write a check that the engine can't
cash!"
Take Care Matthew
I'll give it some thought and draw something up.
One problem is the thrust load could put a side force on a torque cylinder
that might jam it. I have a few low friction ideas I will look into.
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 22:32:42 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
TERF Email wrote:
Use "Hyme" joints? Cables maybe? Any of these should eliminate side
loading with some creativity. Depends obviously on the engine mount, but
this stuff has been done for years in differnt types of brake dynos I have
seen while working for Kelsey - Hayes and large truck manufactureres. ;-)
Matthew Tait
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______________________________________________________
Date: Sun, 10 Jan 1999 22:37:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Glass Star motor mount.
Marvin Kaye wrote:
At 04:00 PM 1/10/99 -0800, you wrote:
I will calculate and post the firewall loads shortly. The tube
size for all these motor mounts are still up in the air.
I would like to do it with an FEA program.
For the record, I used 3/4" OD .049 wall 4130 tubing on the mount which I
just got back from the welder. I chose that particular material thanks to
the recommendation of a few people who are in the business of welding these
things up for OEMs, also because that's what was used on the dynafocal
mount for the Lycoming O-/IO-360 which came with the [Lancair LC20] kit. I
thought you'd be interested.
<Marv>
PS... BTW, my professionally TIG welded mount looks super, is amazingly
stiff, and only weighs in at about 5#, excluding the fittings which get
attached to the engine to provide the mount points. I'll get the entire
weight (mount plus 3 load attachment ears) tomorrow for you. I suspect the
whole thing comes in right around 15-17#.
Take some pictures Marv.
Thanks.
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 22:50:10 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
Brent Regan wrote:
For real time, in the plane data, wouldn't thrust be better. No rpm to factor in.
That way you can compare prop vs manifold for lowest fuel burn for a given thrust.
Brent
Thrust times velocity in feet per second divided by 550 *IS* HP
out of the prop. It would be good for prop development
*AND* engine development.
Hard do do with three or more rubber mounts sharing the thrust load
as Matt's last desertion on this subject implies.
Not to worry guys I have an idea. Drawing soon.
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 22:54:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Tracy's location
facilitator1@juno.com wrote:
Where is TRACY in Fla ?? Virg
He is about 15 miles NW of Bell.
Contact him directly for directions.
rws@altavista.net
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 22:58:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Unproven airframes and non AC engines.
facilitator1@juno.com wrote:
What is WOT ???
Would one dare suggest that you prove the
airframe before using an auto conversion
for flight ?? Virg
WOT is Wide Open Throttle.
A non AC engine and unproven airframe is more risk than
I would want to take on.
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 23:03:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
facilitator1@juno.com wrote:
Put prop on backwards and you still have positive
thrust. Check it out!! Virg
Yes but not as much. It would reduce the torque effect from
the slip stream flowing over the wings.
I am not saying that is the thing to do. Most ground adjustable
props can be moved to a negative angle of attack which will
reverse the slip stream. This also makes it a little more dificult
to tie the airplane down however.
Paul
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______________________________________________________
Date: Sun, 10 Jan 1999 22:35:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More on the force topic
TERF Email wrote:
A thought just occurred to me (scary huh)! To get thrust. Say
your engine mount has 4 mounting points at the firewall. Use a
cylinder at each one. Plumb them all together and measure that
pressure (scratch that you may still need to keep them separate and
add the results other wise theoretically one would "bottom out" giving
you bogus results.) They would each have to have a very short
displacement to prevent the line of thrust from moving around. Use
Hyme joints on one end of each. Ridged or rubber mount the cylinder
basically at the end where the shaft comes out to allow for some
directional normalization and binding but not allow the engine to
drift all over hells half acre. Remember the pistons in these
cylinders shouldn't move much at all. They just measure force.
You could even use some orifice tricks to limit the instantaneous
fluid flow in and out of the cylinders creating a psudo dynamic liquid
vibration inhibitor. (A little trick we learned while working on
semi-active automobile suspension shocks.) Perhaps this can be done
on the "shaft side" of the cylinder while the measurement is taken
independently on the "non shaft side"? Use a ambient pressure
accumulator on the "shaft side circuit" and an oil with a given
viscosity. Then with an orifice at each "shaft side" cylinder port
the frequency response could be trimmed. With 2 one way valves and 2
different orifices you could trim the cylinder to act with one freq.
in one direction and a completely different frequency response in the
other. All of this combined with the rotary's already smooth profile
should make a really smooth system. No more shaking the tail off of
your Cessna 152 when the engine passes through 700 RPM.
To get engine torque should be much easier. Picture a mount
simplified to this; a tube sticking strait out of the fire wall in the
upper LHS. hang the engine on it so it can pivot. Support the other
side of the engine into place with the cylinder. Now by good ole
Newton you have rotational "push back" or the engine torque. A little
math / calculation and whalla. Over simplified obviously but I think
you get the idea.
Best Regards Matthew Tait
--
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______________________________________________________
Date: Mon, 11 Jan 1999 05:57:42 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: What happens to the apex seals if the engine stops while
flying.
Anderson Ed wrote:
JB, I really don't have a clue, others on the list may be able to give
you some feel. However, it is my opinion that without combustion
pressures pressing the seals against the housing, that the amount of wear
due to a wind-milling prop due to a stopped engine will: 1. be so minimal
it would probably defy measurement, 2. Will be the last thing on you
mind and will be the least of your worries, 3. will be over within 8
minutes or much less depending on your altitude.
If you are super cool
dude and really concerned about this wear, you may be able to raise the
nose and lower your airspeed sufficiently to stop the prop from
windmilling {:>}. Me, I will probably be praying too hard and hopingthe wind-milling engine will finally come to life again.
Serious, I do not believe the possiblity of seal wear due to a
windmilling engine should be a factor in any design decision due to no
combustion pressures and very short period of time involved.
Ed
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______________________________________________________
Date: Mon, 11 Jan 1999 07:43:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Feb. Kitplanes Engine Beat column.
Anderson Ed wrote:
Paul, I was rather astonished to read your comment to John Larsen that a
rotary has only one power pulse per revolution. I am certainly no
expert, but I thought that each face (combustion area) of the three
faces of the rotor goes thru a complete cyle of intake, combustion and
exhaust per revolution of the rotor. While I agree that each face only
goes thru the complete cycle once per revolution of the rotor, with
three faces it seems to me that a rotor has three combustion events per
revolution. What am I misunderstanding???
Ed
Even the best of us have trouble with this. One pulse per rotor,
per rev of the OUTPUT SHAFT.
What fools one is intake, compression,
expansion and exhaust are taking place simultanously.
BTW the real subtle beauty of the Wankel rotary is the loads
associated with these strokes are completly contained within
the rotor itself.
The rotor only runs at 1/3 the RPM of the OUTPUT SHAFT.
The Wankel rotary is the most elegant solution to the internal
combustion engine by an order of magnitude.
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 08:04:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap in the airplane dyno
Anderson Ed wrote:
Oops, I stand corrected, Lb-Ft/Sec verses Ft-Lb
Ed
OK guys here it is. A real cheap dyno that will tell you the HP
your engine is generating while you are flying.
You will need a look up table.
HP = RPM X Torque / 5252
This is Matt's idea of using a hydrulic cylinder to measure the torque
on an engine. I added the linear bearings to reduce the friction
caused by engine thrust.
The cylinder piston/bearing shaft must be hardened to Rockwell C
60 and finish ground. It is built in the form of a replaceable
over-haulable cartridge inserted into the motor mount
and retained by a sholder and a snap ring.
The cylinder size is one inch and the Barry rubber mounts are rated
at 100 pounds apiece. See the NL web site for the link to the
Barry site.
It can be calibrated by a large torque wrench.
dynomot.gif
BTW the rotary is so well accepted as a viable aircraft engine
that we find ourselves dealing with advanced engine monitoring and
navigation devices like MPG and takeoff warning devices.
Eat your heart out general aviation :-).
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 08:40:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: New RX7 details.
MAR34807@aol.com wrote:
In a message dated 99-01-10 01:42:46 EST, you write:
However a lot of these issues have been addressed in the very latest RX7
introduced in Japan just a few weeks ago.
Paul, where did you find the info on the latest 3rd gen 99 model on the
engine? I have not heard about this and would like to find out what has
actually been done to the engine! I do know it is NOT the MSPRE engine (yet)
in those Japanese spec 99s. Some airflow characteristics were changed (new
front end) and some accessories, but nothing major.............
>From this web site.
http://www.e.mazda.co.jp/Publicity/Public/9812/981215be.html
Here is part of the press release.
December 15, 1998
The New Mazda RX-7 Powered by 280 PS Rotary Engine
- a pure sports car improved its "Fun to Drive" -
Mazda Motor Corporation today announced the long-awaited arrival of
the new RX-7. Mazda's modern version of a pure sports car will be
available beginning January 21 next year through Mazda Anfini dealers
throughout Japan.
The RX-7 has a legendary tradition for offering driving enthusiasts
the greatest "fun to drive" character. Building on that reputation, the
new RX-7 turns heads with its powerful, unique exterior, and Mazda's
compact, lightweight, and high-powered rotary engine.
The main features of the new RX-7 are:
.1) Enhanced turbocharger efficiency and cooling performance that
afford increased maximum engine power of 280PS (JIS net) for both the
Type RS and Type R. models
-Higher engine power and the new RX-7's light weight achieve a
power-to-weight ratio of 4.57 kg/PS for the Type RS model.
Despite the enhanced driving performance and new equipment, the price
for the 280 PS top-of the line models barely increases. The 5-speed
manual transmission, type RB, with a maximum 265PS engine output costs
2,898,000 yen (one price nationwide), making the new RX-7 more
affordable than ever.
The monthly sales target is 500 units.
Highlights
1. IMPROVED DRIVING PERFORMANCE
Enhanced turbocharger efficiency and cooling performance due to
increased air-intake allows the new RX-7 to achieve a maximum output of
280 PS/6,500 rpm (Type RS, Type R) increased engine power combined with
the light weight of the type R model realizes a power-to-weight ratio of 4.5 kg/PS.
Along with greater output at high engine speeds and an extended top
end, the torque at medium engine speeds has been increased for better
acceleration. Specific changes that have improved engine performance
include:
* The use of abradable seals and increased air flow provided by an
ultra-high-flow turbine achieves a turbocharger pressure approximately
1.2 times previous models.
* Modifications to the internal structure of the main silencer have
reduced exhaust pressure, contributing to lower resistance.
* In addition to increasing the aperture surface area of the
air-intake, including the radiator and intercooler.
* The air cleaner uses a separate air duct that allows air to pass
over the vehicle for more efficient cooling.
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______________________________________________________
Date: Mon, 11 Jan 1999 10:05:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Climb
Anderson Ed wrote:
Paul, thought I would throw in some "real" world data. I have made one
time to climb data collection with the following results:
15F day with RV-6 Weighing 1600 lbs
at 3000 MSL 1450 fpm
at 5000 MSL 1230 fpm
at 7000 MSL 1000 fpm
I estimate based on the comparison of this data with designers data that
engine is producing approx 150hp. I have a 68x72 prop and can reach a
static rpm of 5000-5200 depending on ambient air temp. Aircraft does
climb well at 120 IAS at 5800 rpm, but will hopefully do better now that
I have removed the 2" of foam I had in my air intake. Several folks
have suggested that 2" of foam in the 3" dia duct was unduely
restricting airflow resulting in the 2" lower than expected manifold
pressure. A gain of 10-15 more hp will give me what I have targetted
for performance. I currently can only get 6000 rpm when level flight,
but believe that will improve with tweaks to timing and fuel injection.
Ed Anderson
Obviously you have a lot more than 25 HP left over :-)
I think your prop is still a couple of inches too long and/or you need
better intake and exhaust tuning.
The HP should still be strongly increasing in the 6000 to 7000 RPM
range.
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 19:59:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Feb. Kitplanes Engine Beat column.
Anderson Ed wrote:
Aha! I understand - one power pulse per face per rotor revolution = 3
power pulses per ROTOR revolution. Divided by gear ratio of 1:3 between
rotor and eccentric shaft = 3/3= 1 power pulse per Eccentric Shaft
Rotation.
Thanks
Ed
Good way of explaining it. I'll have to remember that.
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 20:06:11 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Climb
Jeff Spitzer wrote:
Paul wrote:
This is a crude aproximation. I think the drag of the airplane
goes up due to the additional lift required to climb and hence
so does the "CL^2 / pi X Aspect Ratio" induced drag factor so this
calculation is probably optimistic.
In other words its worse than this.
Paul
Actually, no. The method you describe is commonly used to estimate R/C. I
think you already recognize that the HP's you are talking about are net
after PSRU and prop efficiency. As to your last point about error it is
actually the opposite. An A/C will actually have less lift in a climb due
to elevation of the flight path. In a vertical climb you need no lift at
all. The error is usually rather small for GA A/C but not if its a rocket
ship.
Jeff Spitzer
Good point Jeff. There is an slight upward slope to the thrust vector.
On the other hand high aspect ratio airplanes always seem to climb better
for some strange reason. They certainly have higher ceilings.
One may have to run the numbers on these second order effects.
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 20:11:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Feb. Kitplanes Engine Beat column.
Marvin Kaye wrote:
At 07:43 AM 1/11/99 -0800, you wrote:
Even the best of us have trouble with this. One pulse per rotor,
per rev of the OUTPUT SHAFT.
What fools one is intake, compression,
expansion and exhaust are taking place simultanously.
Anyone wanting to get straight in their heads what goes on inside that
trochoid should read Paul Yaw's December Tech Notes. I feel much more
comfortable thinking about these things now that I read through that short
dissertation. It's an article that shouldn't be missed by anyone
interested in the rotary. Thanks, Paul, the fog is lifted.
<Marv>
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______________________________________________________
Date: Mon, 11 Jan 1999 20:13:00 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: What happens to the apex seals if the engine stops while flying.
RJohn15183@aol.com wrote:
Windmilling of an auto conversion has been a bull session topic at our local
EAA. Most seem to feel that with the PSRU, there will be no windmilling at all
due to the gear reduction.
I have no opinion myself but it seems a plausible theory. I'll let you know in
about a year. ;-)
Rob
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______________________________________________________
Date: Mon, 11 Jan 1999 20:22:04 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Rotary engine core prices
BCGARDNER@aol.com wrote:
Paul,
What are people paying for rotary engine cores these days? Here's an ad I saw
today on the Team FC3S email listserve. I'm sure I'd want to rebuild it before
using in an aircraft but...
Barry Gardner
Name: Jim Krupnik
Email: jkrupnik@usa.net
Phone: 678-445-6783
Location: Kennesaw. Ga
For sale or wanted: forsale
Item: 1987 TII runs real well 150k miles, red, needs paint work. Grey int. V
good mech cond. CHEAP for CASH $1,500.
Buying a first or 2nd gen rx7 is a good way to make sure you are getting
a good engine. The down side is it is not quite state of the art for
turbo charging. Would make a fine normaly aspirated A/C engine however.
Paul
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______________________________________________________
Date: Mon, 11 Jan 1999 21:20:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 20B output shaft flex.
MAR34807@aol.com wrote:
>Dave Morris wrote:
However they will still have the inherent (flexing) problem. I have
heard of a NZ engineering firm making 3 rotor shaft for the 20B that are
of a higher quality steel. I'd suggest that if someone wanted to build
up a 3rotor from parts, they use the NZ built shafts instead of the
Mazda ones.
Dave Morris..................DMRH special vehicles
Here is the mention of the "troubles" the output shaft of the 20B have. This
is news to me; I thought Mazda had conquered the forces on that shaft by
adding an intermediate support. And your analyses of this above seems to bear
out the forces acting on the shaft. Any thoughts on this? Where did that info
come from, hugely modified 20B racing engines?
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______________________________________________________
Date: Mon, 11 Jan 1999 21:29:24 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: How about a "certified engine" test??????]
MAR34807@aol.com wrote:
Information to chew on seen on another list..........
It was said ..."I was told by their engineers that any
production aircraft engine has to go to TBO and 100%
power in order to meet certification requirements."
This is common folklore but has no basis in reality or
truth. One must be very careful when talking to
engineers. There is only one "bible" used in the engine
test cell, read on...
The document that governs any certification of any
aircraft engine (be it reciprocating piston engines or
turbine) is Advisory Circular AC33-2B, "AIRCRAFT ENGINE
TYPE CERTIFICATION HANDBOOK".
To cut to the chase; only 150 hours are required to
certify ANY aircraft engine! And so as not to bore y'all
I'll give you the pertinent sections (brutally and
severely edited). Every combination you can think of is
covered in the manual. Single-speed supercharged,
double-speed supercharged, turbocharged, gear driven,
helicopter engines, etc. are all covered in the manual.
Prop, accessories and other good stuff are all addressed
in testing.
Section 33.49 Endurance Test
a.) General...during the runs at rated takeoff power and
for at least 35 hours at rated maximum continuos power,
one cylinder, must be...not less than limiting temp, the
other cylinders must be operated at not less than 50 deg
below the limiting temp...
b.) Unsupercharged engines. . . (1) 30 hr run...alternate
periods of 5 minutes rated take off power...5 min best
economy (2) 20 hr...alternate periods 1.5 hr @max...1/2
hr @ 75%&91% (3) 20 hr...alternate periods 1.5 hr
@max...1/2 hr @ 70%&89% (4) 20 hr...alternate periods 1.5
hr @max...1/2 hr @ 65%&87% (5) 20 hr...alternate periods
1.5 hr @max...1/2 hr @ 60%&84.5% (6) 20 hr...alternate
periods 1.5 hr @max...1/2 hr @ 50%&79.5% (7) 20
hr...alternate periods 2.5 hr @max...2 1/2 hrs max best
economy...
c.) Gear driven engines...etc. (you get the idea...)
AC33-2B is more than 115 (double sided) pages. Make no
mistake, the FAA required testing in the manual is
severe. And of course, if any one of the tests failed it
would have to be repeated. Yes, an engine could have
thousands of hours on it during development, or in
preparation for the certification test. But, bottom line,
a certified engine only has to pass 150 hours of testing.
What I have listed above is a gross simplification of
what is required. For those that are interested in such
things you should get a copy...it makes for fascinating
reading!
BTW, TBO is a manufacturer's term. It has nothing to do
with Certification or AC33-2b.<<
--
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______________________________________________________
Date: Tue, 12 Jan 1999 06:51:13 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 20B output shaft flex.
David Morris wrote:
Regarding the experiance with the 20B's.
Firstly the 1st 1000 engines off the production line are the worst.
Every JC Cosmo (20B optioned) that I have imported into Australia with
the VIN of JCESE-100001 through to JCESE-101000 have had either a dead
engine or a replaced one. (regardless of mileage).
Each time, it's the centre rotor gone with usually a cracked seal or
two. WHY? becuase of the flexing problem, Mazda knew this before hand
which is why the centre bearing ( & thus housing) is so thick. It was a
genourous attempt but failed & Mazda had to replace hundreds & hundreds
of 20B's under warranty due to this. (which explains the surplus of
{used} engine's floating around a few years back). The engines wereusually letting go around the 50k miles area as many of my Japanese
friends have told me.
Because of this embarassing problem the dealerships (once the car died)
had to send the engine's back to Hiroshima for a direct replacement.
They wern't allowed to pull them apart for a re-build like the normal
12A - 13B engines they had done to for years before.
For cars above 1000 (VIN) the shafts must have a different composition
because I have cars floating around with 60K + miles on them & there
still going strong.with original engines. Still this doesn't mean it's
gone away totally. My friends report that when one of the better engines
come in for whatever reason (usually to be installed in a race car) it's
always rebuilt & they find shaft always needs replacing as it's out of
tolerance. Hence the "NIL STOCK" of shafts at Mazda for the time being.
As for the better shafts being made in NZ. My contact there reports he
gets the steel from "British areospace" (if that means anything to you)
as it's the strongest around. They look very simialar to the Mazda ones
& are a direct replacement. I am endevouring to get a pic of one from NZ
to show everyone. As for supply. The team at REDLINE rotary here in
Sydney are about to sign him up as a supplier & distribute his shafts
throughout the world.
REgards
David Morris
The only thing that bothers me about all this is high strength steels all have
the same modulas of rigidity. There must be a machining issue here.
Perhaps there was a resonent conditon in the early shafts.
Notice the unusual lighting holes
drilled in the eccentrics of this picture of a 3 rotor that Jim Mederer
of RB is now building up. Some simple change like this could change the
dynamics. I will ask Jim about it the next time I see him. (soon)
3rotshaf.jpg
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 07:05:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: What happens to the apex seals if the engine stops while flying.
Anderson Ed wrote:
Rob,
Having experienced engine failure at 8000 ft in my 13B powered RV-6A
with at 68x72 prop, I can tell you in my case that even after setting up
best glide airspeed of 90 MPH, the prop did continue to windmill. I was
just as happy that it did as when I finally realized that my fuel gauge
was indicating fuel from the selected tank, but the fuel pressure gauge
said Zero fuel pressure- and I switched tanks the engine caught and
started running. If the prop had stopped then I would have had to
remember to press the starter button {:>}. Clearly, it depends on theprop, PSRU and engine, but again, I think that for the few minutes you
may be windmilling that it is unlikely any damage would be done. But,
just a personal opinion.
Ed Anderson
Such is the life of a pioneer :-)
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 07:36:12 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing the tip seals?
What do all of you think of these apples?
http://www.hurley-engineering.ltd.uk/
tipsealslube.gif
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 08:33:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
http://www.hurley-engineering.ltd.uk/contents-Tip_Seals.htm
Opps lets try that again.
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 08:37:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A beter way of lubing the tip seals..
Sorry guys one more time delete previous.
I hope this will work this time.
Paul
http://www.hurley-engineering.ltd.uk/HME_Direct_Tip_Seal_Lubrication_System.htm
--
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______________________________________________________
Date: Tue, 12 Jan 1999 08:42:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing the tip seals?]
Anderson Ed wrote:
Looks simple and like it would be effective. I wonder how the valve is
controlled ? Centrifical force against a spring?, metered hole??
However, at $400 per rotor set, Exchange. I think I will keep adding
oil to my fuel even if 99% is simply burned.
Ed
This could be the needed breakthrough in the burned oil smog
problem which may keep the rotary alive as a car engine.
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 08:46:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 20B output shaft flex.
ingenuir@ix.netcom.com wrote:
Hello, Paul.
On the subject of alternate suppliers for shafts:
To oversimplify the fatigue life expectancy of "similar" engine parts:
Fatigue life is the sum of cycles to crack initiation and cycles of crack growth.
Fracture mechanics analysis assumes all specimens have initial flaws, probably in
the most critical locations. FMA predicts whether the flaw will propagate and how
rapidly. Fracture control requires inspection of the part to guarantee flaws are
below some critical size. Flaws may be either of the surface or internal.
Effects of different steels on the life of engine parts is mainly due to strength
and toughness of the alloy. You're right, even cobalt steels have only a small
increase in their elastic modulus. Also, vibration modes are dominated by the cross
section areas that are based on bearing sizes and similar fixed parameters in a
given engine.
Aircraft quality parts have to be right all the time, be sure you know your
supplier understands his processes and conforms to them.
Gary Moir
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______________________________________________________
Date: Tue, 12 Jan 1999 10:09:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Climb
Jeff Spitzer wrote:
At 08:06 PM 1/11/99 -0800, you wrote:
On the other hand high aspect ratio airplanes always seem to climb better
for some strange reason. They certainly have higher ceilings.
One may have to run the numbers on these second order effects.
Paul
These are not "second order" effects. Higher aspect ratio airplanes have
much less induced drag at climb speeds. This results in less drag and more
reserve power for climb. The same is true at high altitudes where
indicated airspeeds are low (CL is high) but TAS is high resulting in
higher power requirements. That is why the U2 wing is long and skinny.
Jeff Spitzer
Thats what I said: "CL^2/pi X Aspect Ratio" :-)
Second order I was referring to the thrust vector angle.
Paul
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Date: Tue, 12 Jan 1999 10:19:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Improved real cheap in the airplane dyno
Anderson Ed wrote:
Paul,
looking at your Real cheap dyno design and thinking about how to adapt
it to an aircraft with the power plant in the plane. If I understand
the design the load has to be in compression, but rather than reverse
the prop {:>}, I was wondering why you could not design a bracketarrangement whereby, you could place the dyno to the rear of the
aircraft (tractor prop) with the front of dyno facing aft. Then a cable
could be attached to a each side of the bracket which is placed over the
front of the dyno placing a compression load on the dyno.
Ed
No need to reverse the prop.
I think I was not too clear on this. It is much simpler than it looks.
This is based on the Questair type engine mount where the two front
rubber bushings react all torque load. One is under compression and
the other is under tension. Choose one based on your prop rotation.
Could be the left side looking forward if your prop is rotating
clockwise looking forward... or... the right side if counter clockwise.
The thrust load is reacted by both front mounts in the pure
manifestation of the Questair type motor mount. In most of
the ones I have drawn so far it is reacted by all three rubber mounts.
Now if you have a dyno focal type mount forget it :-)
It becomes too complicated.
rv6motm.gif
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 16:37:38 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Take off monitor.
Tracy Crook wrote:
Several versions of the PIC have 16 bit counters, but why not use one of the
monolithic G sensors now available and skip all the mechanical stuff?
Incorporate this in my instrument too? I sense "feature creep" coming on.
:-)
Tracy
Funny you should mention that. I have been fighting that battle since 1975.
The thing about accelerometers is they need a stable reference plane.
AKA a stable table. Aircraft pitch changes are not allowed without
a stable table. The next thing that happens is you need a conditioning
amplifier. Then an analog to digital converter. Are we having fun yet?
On the other hand here is the psuedo code:
All pulse or digital.
Background program.
....
....
Loop to background.
#Routine to be executed every one millisec.
#Upon one millisec interrupt do this:
Disable input to counter...\
............................\
Read counter.................\
..............................\
Reset counter..................| 20 micro seconds in 1 MHz 6502
............................../
Re-enable input to counter.../
Add counter value to distance accumulator.
Subtract counter value from old counter value.
If distance accumulator is greater than decision distance
and new counter value minus old counter value is less
than acceleration threshold, abort takeoff and end program.
If not.... continue.
Store current counter value in old counter value.
Return to background.
#End of program.
#The runway length can be merely the distance down the runway you
#want to abort if the accel. is below par AKA decision distance.
Yes i guess it is feature creep :-) But you can do it Tracy :-).
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 16:44:07 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ignition Timing
StJames515@aol.com wrote:
In a message dated 1/11/1999 9:18:40 PM Central Standard Time, Marvin wrote:
Anyone wanting to get straight in their heads what goes on inside that
> trochoid should read Paul Yaw's December Tech Notes. I feel much more
> comfortable thinking about these things now that I read through that short
> dissertation. It's an article that shouldn't be missed by anyone
> interested in the rotary. Thanks, Paul, the fog is lifted.
>
> <Marv>
Read the Jan article too, Paul Yaw really opened my eyes to the whole idea of
timing the rotary. Now all I need is a little "exactly how do I do that?"
Tommy
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Date: Tue, 12 Jan 1999 16:42:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 20B output shaft flex.
MAR34807@aol.com wrote:
Would this person know the id of the engine numbers of the affected engines?
Vin number of the 20B Cosmo does one no good as the importers send only the
engine! I'm curious about the 20B in my garage! It tests ok........
In a message dated 99-01-12 08:59:06 EST, you write:
<< > Firstly the 1st 1000 engines off the production line are the worst.
> Every JC Cosmo (20B optioned) that I have imported into Australia with
> the VIN of JCESE-100001 through to JCESE-101000 have had either a dead
> engine or a replaced one. (regardless of mileage).
Or what to look for in subtle differences in the shaft.
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 16:40:26 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Parkman-comments on the homebuilder movement
MAR34807@aol.com wrote:
I don't think anyone has mentioned the EAA as a source of "oversight" in the
kit building process! They offer this informal sort of service as a deterrent
to just the kind of thing that happened.....it does not help the industry/EAA
or anyone if someone kills himself because of lack of knowledge or advice.
That being said, I know individual(s) who were either crazy or stupid enough
to go ahead blindly even after being given constructive advice from genuinely
knowledgable EAA members, including some who looked at the assembly of parts
and said 'You will certainly kill yourself unless you do such and such', so I
guess it is "survival of the fittest" so to speak.....
Aviation has been compared to a self cleaning oven.
Too bad you don't get to fly before you have children.
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 16:51:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: ROTARY ENGINE NEWSLETTER
DAVID TAYLOR wrote:
DEAR SIRS,
I WOULD LIKE TO RECEIVE COPIES OF YOUR NEWSLETTER (PAST, PRESENT,
AND FUTURE) ABOUT THE USE OF ROTARY ENGINES IN HOMEBUILT AIRCRAFT.
I AM CURRENTLY WORKING IN PANAMA ON A CONTRACT THAT ENDS DECEMBER,
'99. IN AUGUST OF 99, I INTEND TO ORDER A ZENAIR CH-701 AND AM
CONSIDERING A ROTARY ENGINE CONVERSION FOR THE POWERPLANT. THE CH-701
WILL ACCEPT ENGINES UP TO 100hp AND INSTALLATION WEIGHTS UP TO 170lbs.
ANY INFORMATION SENT WOULD BE GREATLY APPRECIATED AND A POINT OF
CONTACT FOR ANYONE WHO HAS SUCH AN AIRFRAME/POWERPLANT COMBINATION WOULD
BE MOST USEFUL.
THANKING YOU FOR YOUR TIME AND SERVICE
SINCERELY,
DAVID TAYLOR
Unfortunately we don't have back issues. They would be way too much
to download. We are talking hundreds of megs here. We are working
on books however.
The CH-701 sounds great for a one rotor. See the NL website
for a source of one rotors. The source has only up to
80 HP but with some intake and exhaust tuning and running
on gasoline you could get 100 HP.
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 17:01:04 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: What happens to the apex seals if the engine stops while
flying.
RJohn15183@aol.com wrote:
In a message dated 1/12/99 8:12:34 AM Central Standard Time,
rotaryeng@earthlink.net writes:
Rob,
> Having experienced engine failure at 8000 ft in my 13B powered RV-6A
> with at 68x72 prop, I can tell you in my case that even after setting up
> best glide airspeed of 90 MPH, the prop did continue to windmill. I was
> just as happy that it did as when I finally realized that my fuel gauge
> was indicating fuel from the selected tank,
That's good news as the nature of the EAA bull session no windmilling was seen
as a negative for the very reasons you describe. I'm glad I can dispel that
myth at the next meeting.
Thanks for the first hand observation!
Rob
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Date: Tue, 12 Jan 1999 17:18:28 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Take off monitor.
OK I going to brag a little. My 6502 road test equipment was used
by the Rutan Voyager team to measure the acceleration
performance of the Voyager fully loaded to see if
it could really take off and climb.
Cover Article in Road & Track.
BTW first bug fix :-).
"Subtract counter value from old counter value".
Should read: "Subtract old counter value from new counter value."
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 18:52:32 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
George Moore wrote:
Paul,
In studying the Hurley Engineering, direct tip seal lubrication
system, many questions came to mind. First, hasn't this been tried
before ?
Not to my knowledge. I have three or four books on the Wankel rotary
and a couple of dozen technical papers and I do not recall
seeing it.
The whole idea of a very small diameter hole(s) from the tip
seal slot, to the rotor inside bore, where oil is sprayed, just seems
too logical and simple not to have been tried before ! My second
question was, how much blowby can be expected between the seals and the
seal slot, in other words, what could be expected in terms of
compression loss and resulting cranckcase overpressure and
contamination, as a result of a small diameter hole by itself ?
Very very good question and Mr. Hurley is out of town for a few days.
I will ask him when he comes back. Or you can ask him yourself.
His email address is on there someplace. No! wait! here it is.
"Eamon Hurley" <eamon@ehurley.force9.co.uk>
Which brings me to my third question. Do you think that the heart of their
"system" is the tiny control valve, which to satisfy my above worries
would be a miniature check valve that would let oil to the seals, but
close on compression ! Or is it merely an orifice to control the
compression bleed-down rate?
Another good question. I think I would at least TRY the check valve.
I am really curious if you know of any experimentation done by
others on this simple (and probably too good to be true) concept !
Also, I would really enjoy hearing your opinion on the other 2
Hurley tip seal designs, the duplex tip seals and the swing tip seals,
which obviously require a fair amount of maching to the rotor at the tip
seal slot . The duplex seemed to have possibilities, but I thought that
splitting it in to 2 pieces horizontally would make it weaker, but at
the same time I saw an advantage in terms of of twisting flexibility.
Damn, I wish I could make up my mind and these abstract analysis !
I don't think much of the swing design for several reasons.
It looks like two line contacts on the rotor houseing surface.
If it wears down to some average radius it might lift off due
to an aerodynamic air bearing effect. The big problem is
it does not look like it can move in and out of the slot.
Might work. I am not saying it won't. I would like to hear
what Jeff says about all of it.
He is a much better person for the job than I.
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 18:59:26 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
Fred Zapponi wrote:
Given the following:
1. Fixed pitch prop
2. Closed throttle
3. Descent mode
If a butterfly type valve was installed in the exhaust system to choke
the exhaust flow down, could the prop be slowed to provide an airbrake
effect, thereby increasing rate of descent?
Regards.
Thats a good question I don't have an answer for. I think, as
I recall, you get more drag with the fixed pitch prop wind milling
rather than stopped.
I am probably wrong. It has been a long time since I took
the PP exam.
Never the less it sounds like what you are driving at is
a truck type exhaust brake.
Paul
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______________________________________________________
Date: Tue, 12 Jan 1999 19:09:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Chuck Harbert progress report and 13B/20B turbos?
Chuck_Harbert@arkwright.com wrote:
Paul, I finally got the turbo 20B running last Friday. It started right up
and although I'm using some incorrect senders (water and air temp), it
actually ran very smoothly. The interesting part was how quiet it was at
higher rpms (no discernable pulses). At lower rpms (under 1,500), you can
hear the pulses, but it is still much quieter that a normal a/c engine.
I've got a couple of small bugs to work out, but nothing of consequence (I
hope). Also, I can't adjust the engine computer (Microtech) until I get
the correct sensors. The engine computer has a 4"-4 line, 10 item direct
readout that gives you continuously what the computer is sensing (rpm,
water/air temp, tps %, timing, inj msecs, man press, a/f ratio, etc) which
sure makes it easy to tune. I don't have the prop on yet, so I can't load
the engine to bring the boost up. I'll get back to you after I get it
further along.
I just saw the memo on the 20B e-shaft problems which obviously has me
concerned. I've got 2-20B's, one with engine numbers and one w/o. Is there
any way of identifying which engines I have?
p.s. I happened to talk to Ola (Tech Engr) at Turbonetics yesterday and
he's okay with airplanes, as long as he knows it's "experimental". He will
help you size it for the application, but you'll need to know some of the
technical jargon because he can't stay on the phone too long. The other
alternative if you're not a "motorhead"is to have Dave Atkins, Paul Yaw, or
somebody in the business help you develop the powerplant.
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______________________________________________________
Date: Tue, 12 Jan 1999 21:36:17 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
George Moore wrote:
Paul,
Since the rotor tip seals have always been a major source of
discussion in the Rotary design, I was hoping that we could get some
input from Jeff, Tracy, Matthew Tait, Paul Yaw and all of the Engine
experts that we are fortunate enough to learn from on this Newsletter.
I keep thinking, that if prolonged tip seal life is as simple as a
very small hole drilled from seal notch to rotor bore, this would be a
tremendous fix ! The more I think about the Hurley "control valve", the
more I am convinced, that it would be impossible to build a mini check
valve, that small, that it would survive in the dirty carbon building
environment of an internal combustion engine, and therefore this control
valve is nothing more than a calibrated orifice !
Well Paul, I think you presented us with a really interesting topic
on a day that every was out to lunch !
I can think of one way of doing it with a rotary valve built into
the rotor bearing in the form of a slot that shuts off the oil
supply during the combustion phase and part of the exhaust stroke.
There would be a column of oil that had no where to go that would
be subjected to combustion pressure on its top end.
I agree. If this works it could be a real breakthrough in emmissions
reduction.
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 07:29:16 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
Charlie and Tupper England wrote:
Paul wrote:
Fred Zapponi wrote:
Given the following:
1. Fixed pitch prop
2. Closed throttle
3. Descent mode
If a butterfly type valve was installed in the exhaust system to choke
the exhaust flow down, could the prop be slowed to provide an airbrake
effect, thereby increasing rate of descent?
Regards.
Thats a good question I don't have an answer for. I think, as
I recall, you get more drag with the fixed pitch prop wind milling
rather than stopped.
I am probably wrong. It has been a long time since I took
the PP exam.
Never the less it sounds like what you are driving at is
a truck type exhaust brake.
Paul
Fred & Paul:
I'm no aero engineer, but the empirical proof is easy. Think autogyro.
Charlie
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Date: Wed, 13 Jan 1999 07:32:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 20B output shaft flex. Identification part numbers.
David Morris wrote:
G'day from DMRH
Regarding the 20B shafts. This is what I've worked out for the 20B
production runs.
If the rotor housings have a number from 001 to 999 then it's the first
series.( the real problem ones)
If it's got A-001 to A-999 then it's from the 2nd series
If it's B-001 to B-999 then it's the 3rd series, etc.
Chances of it making to the D series are very slim as they simply didn't
make that many 20B powered Cosmo's.
REgards
David Morris
http://www.3rotor.com/dmrh
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______________________________________________________
Date: Fri, 15 Jan 1999 07:41:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Powersport Rotary
Cole and/or Carol Smith wrote:
I keep waiting for someone to comment on the Powersport R&D. I had
a'couple of conversations with Everett Hatch before his sad accident but
have not heard much about his engine since. Thanks, Cole Smith
Ray Richardson Jr bought the assets of Power Sport.
So far I have heard nothing about his plans.
His email address is:
"Ray Richardson Jr." <ratech@earthlink.net>
You might want to try contacting him directly.
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 07:51:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
Anderson Ed wrote:
The answer is a windmilling fixed pitch prop almosts acts as a flat
plate drag area and your drag is higher than a fixed pitch prop that is
not rotating. My prop may have continued windmilling because I had the
throttle near WOT when the tank ran out of fuel - I did not close the
throttle. I guess even if the closed butteryfly would cause the prop to
act more as an airbrake, I personnally would want to know why you want
to do that. If the engine is quiet, I would think you want all the glide
distance you can get and not the addition of a "drag brake".
Ed
I think he was thinking of using the engine to increase the rate of decent.
Real clean airplanes have a problem coming down and spoilers or
speed brakes sell quite well for those types of airplanes.
I am somewhat surprised that more pilots don't use forward slips.
It was not taught to me when I got my formal pilot training
20 or so years ago. When I was a kid hanging around Falls Church
Airpark 50 years ago and informally learning to fly, all those young
ex WW II pilots taking me for rides in J3's and Champ's always slipped
just for the fun of it.
The academic question is: do you get more drag if the prop is rotating
faster or more drag if it is rotating slower, because of increased retarding
torque one the prop shaft?
I would guess the HP required to rotate the higher retarding force engine
at the same RPM would be greater so that would translate into increased
drag. On the other hand if the engine rotated slower the drag might
be the same. My guess is we will never know until someone tries it.
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 10:02:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
Anderson Ed wrote:
Having learned to fly in an Aeronical Champ without flaps, the forward
slip was the standard "Flap Deployment" manuever. Not needed often in
aircraft with flaps, but while flying with FAA examiner (who pulled the
power off on a Piper Warrior at 2000 MSL over a small airfield and told
me to land it without touching the throttle), I came in with a little too
much altitude and even with full flaps was going to touch down about 1/3
down the runway. So, to kill a little more altitude, I threw in a
little forward slip and that did the job. However, from the sharp
intake of breath from the young (former F-15) Pilot who was riding OJT
in the back seat, I don't think he was familar with the maneuver.
Ed Anderson
Great story Ed. :-)
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 09:58:28 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Wish list 13B
Karl Szczypta wrote:
Paul,
Have you any "spec" info put together regarding a "typical" 13B install. Perhaps
Tracy's and Ed's config's. At this time my interest is mostly in FWF weights and fuel burn.
I've seen the O-320 comparisons but it would be nice to narrow it down. I would like
to work out some calculations regarding range and cruse. You know the typical
08FL at 75%, 65%, etc type numbers.
I will leave these questions to Tracy and Ed. The horses mouths so to
speak.
A way of estimating it of course is using the BSFC number of 0.5 pounds
of fuel burned per HP hour. Tracy thinks he is getting around 180 HP max
as I recall and Ed is estimating 150 HP max. Calculate the percentages
of power you are interested in and then multiply by 0.5 which will
give you the pounds of fuel burned per hour. Then divide by six for
six pounds per gallon fuel weight and that will give you gallons per
hour.
Do you have a wish list 13B engine you would love to put together?
IMHO Almost any year after 1989 is fine.
I would choose a four port engine for simplicity in fabricating
an intake manifold. For normally aspirated pay particular attention
to tuning the intake and exhaust pipes for max power at about 6000 RPM.
Don't be fooled by car racing type manifolds.
They are optimized for 7000 to 8000 RPM.
See the web site for
suggestions for intake and tuned exhaust systems. Generally you need pipe
lengths of around 31 inches.
Tracy is experimenting with another type of
tuned intake manifold that is somewhat more compact.
I would get Tracy's
injection system since he is adding MPG display and an abort take-off
warning monitor (I hope. I wish?) :-)
On that topic
how about a 13B turbo version. What about the weight differences between the two?
Yes it is heavier by about 50 pounds I would guesss. Make sure you get a late engine
(1991 up) with the knock sensors on the rotor housing. Also plan on a very effective
intercooler. Get an Inconel tubo charger from Turbonetics and fab an Inconel
exhaust manifold.
Has anyone done any investigating here? After following the info on the forum it
sounds like the turbo would quiet things down needing a smaller muffler.
The muffler is not that big a deal. A VW aircooled bug type tangential input
muffler works well and can weigh as little as six pounds using Inconel.
All "I" would be interested in is normalizing not HP gain. For my project a Vision
all I would need is a 160hp or so.
Thanks,
Karl Szczypta
Yes. Several people are flying rotaries. Tracy probably has the most hours
in an airplane going on about 1000 any day now.
160 HP should not be that hard to get out of a normally aspirated 13B.
People have obtained 700 HP for short periods of time from a turbo 13B.
250 HP A/C use out of a 13B turbo should be no problem.
Therefore normalizing is no problem at all but don't be fooled into thinking
you can do without the intercooler. You will need it at high
altitude to reduce the chance of detonation.
Detonation has been known to crack apex seals.
The engine won't stop running but the rotor housing will
be scratched with an eventual degradation of power. New rotor housings
are expensive. Robust ceramic apex seals are available from Ianette at about
$1200 an engine set. IMHO they won't be needed if you are careful about
detonation.
The key to a successful rotary aircraft engine is the cooling system.
As much heat goes out the cooling system as what comes out of the prop
in terms of HP. One HP is 746 watts. Therefore your cooling system
must disipate 160 HP times 746 watts or 119,360 watts or about
one hundread 1200 watt electric room heaters. Stop and think about that
for awhile.
BTW any internal combustion engine has the same relationship more or less.
Not just the rotary. The reason it is so easy to cool a car engine is
they only generate 30 to 40 HP on average. An aircraft engine is another
matter entirely.
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 18:55:28 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 900 HP Raqcing Beat 3 rotor.
This is Jim Mederer Racing Beat's new 900 HP three rotor.
The rear and one intermediate housings are aluminum.
The turbo charger is the largest available
and is the same as the one used on the Orenda A/C V8.
The turbine is Inconel. I have some pictures
of the Inconel exhaust manifold which I will upload
shortly.
The water pump is used on sprint cars and pumps about
60 gallons per minute at 7500 RPM.
The dry sump oil system will run at 150 PSI and pump
about 20 gallons per minute.
One of the scavenge pumps is used to scavenge the turbo
oil supply.
Target HP is 900 at 7500 RPM. The engine is actually
a 13G three rotor and not a 20B. The differences are minor.
Boost will be 20 to 30 psi.
Wait till you see the size of the intercooler :-)
I was wrong about two of these engines going into
a scale jet fighter. The airplane they are intended
for is a six passenger business jet type airplane.
The cost of the engines are roughly 1/20th of an equavalent
turbofan and burn less than half the fuel.
Further more the throttle response will be five or ten
times faster than a turbofan.
As you can see the turbo charger will be partially
in the fan duct for cooling, air intake supply and
heat recovery reasons.
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 20:22:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Wish list 13B
Rodger Hilyard wrote:
Thirty one inches long and what inside tube diameter?
Rodger
Inch and a half to an inch and three quarter.
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 20:29:23 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 900 HP Racing Beat 3 rotor.
Here is a picture of the fan end. There is some serious air
going into that serious tubocharger.
Good view of the alloy end housing.
Note the Racing Beat peripheral intake ports.
Note also the four studs for each exhaust port similar
to the Everett Hatch concept.
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 20:46:41 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 900 HP Racing Beat 3 rotor. Exhaust manifold
Be sitting down when you ask Jim how much he wants
to build another one of these Inconel exhaust
manifolds.
Jim had 0.065 wall 625 Inconel tubing custom made for this job
using a tubing mill.
It was then sent out to be bent into three
inch radius 180 degree bends. the manifold was then welded
up from short sections of the bends and stright sections.
The wrinkle belly's are off the shelf rocket fuel
or turbo jet hot section plumbing flex sections.
The round outlet is the exhaust blow off valve mounting
and the rectangle is the turbo input to the turbine.
Paul
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______________________________________________________
Date: Thu, 14 Jan 1999 05:50:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
Michael McGee wrote:
Hi, just an old Physics major on the sidelines here.
If you think of the windmilling prop problem in terms of energy:
1) The engine requires a small amount of energy to idle or to turn the prop
at windmilling rpm. When the engine is running or making power that energy
comes from the gas in your fuel tank. That is potential energy in the fuel
converted to kinetic energy in the air the prop is moving.
2) If the engine is not making power and the prop is windmilling the energy
of the turning propellor and engine (friction) and pumping losses (open or
closed throttle) has to come from somewhere. That somewhere is the
potental energy of altitude or more precisely altitude loss. Therefore if
you stop the prop you will stop the energy drain in your altitude, the gas
tank for the windmill.
Now as an owner of Continental powered vehicles I'm not willing to risk
cracked cylinders to prove this. If one of you water cooled folks were to
do some test descents, say an average of five runs from 10,000 down to
5,000 in each of the two test modes (windmilling vs. stopped) over a nice
looonnng runway in case you didn't get a relight, my bet is that you will
see a difference in the descent times at a given airspeed held constant for
the test runs.
Well that got a little long winded ;)
Mike McGee N6358G Vancouver, WA jmpcrftr@teleport.com
"There is something fascinating about science.
One gets such wholesale returns of conjecture
out of such a trifling investment of fact."
Mark Twain
--
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______________________________________________________
Date: Thu, 14 Jan 1999 05:59:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dyno tuning.
TERF Email wrote:
Paul Yaw
I agree whole heartedly with your dyno statements. This is why I don't
have any engines in the air yet. I have a couple of the kit plane
manufacturers chomping at the bit to get one of my new 3 rotor jobs, but
until I have the full firewall "forward" package proven on dyno they aren't
getting anything. I have had to grow a bit of a thick skin when people
chuckle and don't take me seriously because "I don't have any in the
air"...... However I haven't had any come out of the air and I don't intend
to if I can help it.
I have been delayed by the unfortunate breakup of my marriage and sale
of my house but the dyno goes back on the top of the list in the beginning
of Feb. I will try to make (interesting) progress reports as things start
running if Y'all are interested. I am good for 850 HP, 10,000 RPM steady
state. I designed the dyno to heat the intake air and simulate altitude
among other things. I can also tilt the engine +/- 45 deg in roll while it
is running under power. I went to great pains to design a special aircraft
dyno that could simulate virtually any flight condition........
Before the thing hits the air. I want to hook a video, and infrared video to the
system to get more elaborate temp measurements and look for hot spots.
Please be patient I am getting there..
Matthew Tait
Matt. Don't worry too much about 45 degree in either direction.
Only race cars and aerobatic airplanes have that problem. The
gravity vetor always stays pointed stright down in a properly
flown airplane.
BTW Jim Mederer of Racing Beat and I were discussing that yesterday.
He was rather surprised that a plugs up rotary would work given the drain
back passages in the front housing.
Paul
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______________________________________________________
Date: Thu, 14 Jan 1999 06:05:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 900 HP Racing Beat 3 rotor. Exhaust manifold
Paul Yaw wrote:
Hey Paul,
Any idea where I could get the "wrinkle belly's" Are they made of
inconel as well?
Paul Yaw
I forgot to ask.
Call Jim. Tell him you saw the picture on my news letter and
you would like to know. He is very up front about this stuff.
Please let us know when you find out.
Yes. They too are made of 625 Inconel.
Paul Lamar
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______________________________________________________
Date: Thu, 14 Jan 1999 07:07:32 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?]
Anderson Ed wrote:
Having had a fortunately, temporary experienced with the windmilling
prop, I for one am going to forego the suggested experiment by Michael.
I regret that I was unable to focus on the data collection aspects that
the opportunity unexpectedly offered, but lets just say - I was
otherwise occupied at the time. I am certain that a cooler head would
have thought "what a great opportunity to collect impirical data.
Now, if I can just get the prop to come to a complete stop, I can get the
other data set". Alas, that panicie little voice in the back of my head
gibbering about "Oh, my gosh, the engine has quit, Oh, my gosh, your
going to crash, Do something you Lard head, don't just sit there with
your eyes all agog and your thumb in an inappropriate location!, You
should have worn the parachute!,etc!..". Maybe next time.{:>}
However, everything, I have read and heard definitely confirms
Michaels analysis. A Non-feathered (or fixed pitch prop) windmilling will
substantially increase your rate of decent. I am sure all (most) of you
have seen movie thrillers involving pilots trying desperately to feather
windmilling props to: 1. Minimize drag to maintain controllability on
multi engine aircraft, 2. Minimize drag so as to keep/gain just enough
altitude to get over that next ridge line, 3. Stop the engine from
rotating so that the oil starved crankshaft won't have the windmilling
prop twist off when the crankshaft locks up.etc, etc.
But, in all seriousness, it is recommend by some that a test program
include just that set of tests, so that you will know just how far you
can glide with prop stopped vs windmilling. Not many do it
(intentionally that is) to my knowledge.
Ed Anderson
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______________________________________________________
Date: Thu, 14 Jan 1999 08:05:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
Jim and I discussed the Hurly Engineering oiling system for apex
seals and his thoughts on the subject were it is an answer
to a question that nobody asked. He feels the problems
people are having with the third generation RX7 electronicaly
controlled apex seal oiling pump are due to owners
cranking up the boost. He feels if the engine is
allowed to run the stock boost the tip seals outlast
the rotor housings. In other words for a couple of
hundread thousand miles. The apex seal oiling must
be matched to the power output of the engine as the
oil cools the seals.
He has never had a problem with short
term apex seal or rotor slot wear on endurance racing
engines despite some of them running the entire season.
No competive piston racing engine can make that claim.
The only worn apex seals he has seen are those from an abused
engine, a failed apex seal oiling pump or an engine
with well over 150,000 miles.
I still think it has applications in street engines if
it can reduce the amount of oil burned in the combustion
chamber for smog reasons. Matching the oil flow to to the
apex seal with HP remains the major problem.
For aircraft just mix one or two onces of two cycle
oil with each gallon of gas and forget about.
Paul
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______________________________________________________
Date: Thu, 14 Jan 1999 15:58:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
Alfonso Lebron wrote:
Reading the last two paragraphs made me think about just the opposite
of air... water.
For one, "Matching the oil flow to to the apex seal with HP..."
reminded me of some of the new two stroke outboard engines being
produced by Evinrude/Johnson. Instead of mixing the oil with the gas
or using an oil injection pump, they use the Fitch fuel injection
system which injects gasoline and a metered (by pump) amount of oil
together into the cilinder/s. I was guessing this could be a good
departure point, since outboards, especially in bass boats are used a
great deal of the time at full power.
On the other hand, "mix one or two onces of two cycle oil with each
gallon of gas" seems to me that it gives a very large variation in the
final amount (minus 50% to 100% increase). Maybe the above could fine
tune a bit the final correct amount. I will try to get mode specifics
about the oiling in this system, time permitting.
Anybody adding some knowledge on this?
Alfonso Lebron
Matching the oil flow to HP was for smog reasons.
I was not too clear on that point.
A little extra oil won't hurt the aviation rotary.
In fact better too much than too little.
Paul
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______________________________________________________
Date: Thu, 14 Jan 1999 15:59:36 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
facilitator1@juno.com wrote:
EAA test showed that a stopped prop was like getting a boost in airspeed.
Much less drag from a stopped prop, better glide length.
Virgil
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______________________________________________________
Date: Thu, 14 Jan 1999 15:54:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Rotory in Mini 500
bryan.wilkinson wrote:
On Thu, 24 Dec 1998, Paul wrote:
P.A. Williamson wrote:
Paul,
Myself, and a few of my friends, are having a small (as in getting
killed) problem with a kit helicopter we enjoy. I'm sure you've seen
it... the Mini500. What's happening is that stinkin' Rotax is going tits
up at the worst time...about 50 to 100 ft AGL.
SNIP
Our "biggest" problem is that dang Rotax.
SNIP
Over here the problem would apear to be the big & small ends letting go
- rotax have a special tool to check on bearing play IIRC.
Maybe a helo is the worst - case scenario for dynamic stress ?
Bryan
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______________________________________________________
Date: Thu, 14 Jan 1999 23:49:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A real cheap dyno
Frank Davis wrote:
Paul,
This falls under the catagory of "little known but useless bits of
information", or "there's nothing new under the sun". The A-1 Skyraider
(aka AD to those of a Naval persuasion) has a Torquemeter or Torque Oil
Pressure gage which gives the pilot a direct indication of HP or BMEP
prouduced by the R3350-26WD engine. The USAF Flight Manual (-1) states
that the torquemeter "provides a reading of propellor shaft torque oil
pressure calibrated in pounds per square inch". Unfortunately no
further information is given as to how the pressure is generated. I
guess dumb pilots don't need to know stuff like that. Conversion from
TP (psi) to HP is by the formula: BHP=TPxRPM/142. Manual leaning for
cruise is done by setting rpm and leaning for max TP. Torquemeters for
homebuilts (or not-homebuilts) is a good idea.
Cheers, Frank
Sounds exactly what we have in mind here. the 142 is going to
vary with the size of the hydrulic cylinder.
The sketch is now on the NL web site for those new subscribers.
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 00:04:39 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
Paul Yaw wrote:
Paul wrote:
Jim and I discussed the Hurly Engineering oiling system for apex
seals and his thoughts on the subject were it is an answer
to a question that nobody asked. He feels the problems
people are having with the third generation RX7 electronicaly
controlled apex seal oiling pump are due to owners
cranking up the boost. He feels if the engine is
allowed to run the stock boost the tip seals outlast
the rotor housings. In other words for a couple of
hundread thousand miles. The apex seal oiling must
be matched to the power output of the engine as the
oil cools the seals.
I have had the same experience. If the engine is built to withstand the
additional heat loads, the apex seals live quite well. I do feel
however that metering too much oil into the combustion chamber of a
turbo engine can cause problems of its own. Engine oil will reduce the
octane rating of the fuel which could lead to detonation, or require
that the engine run with less ignition advance to avoid detonation.
This will reduce BSFC. Supplying additonal cooling oil inside of the
rotor, and modifying the water jackets in the hot area of the rotor
housing will, in my opinion do more to reduce seal and groove wear than
additional oil in the chamber ever could. I disagree that the injected
oil cools the seals. Its purpose is simply to lubricate. Oil itself
does not have better cooling properties than gasoline. The apex seals
are cooled through their contact with the rotor housing, and the rotor.
He has never had a problem with short
term apex seal or rotor slot wear on endurance racing
engines despite some of them running the entire season.
No competive piston racing engine can make that claim.
The only worn apex seals he has seen are those from an abused
engine, a failed apex seal oiling pump or an engine
with well over 150,000 miles.
I still think it has applications in street engines if
it can reduce the amount of oil burned in the combustion
chamber for smog reasons. Matching the oil flow to to the
apex seal with HP remains the major problem.
For aircraft just mix one or two onces of two cycle
oil with each gallon of gas and forget about.
The two stroke guys are really on top of this. Many synthetic two
stroke oils do not lower the octane rating appreciably, and it is
designed to go into the combustion chamber. My preference is Yamalube
R, available at most motorcycle shops. I suspect that Mazda has reduced
metered oil over the years for the sake of reducing carbon buildup
inside of the engine, and extending the life of the catalytic
converters. You would be amazed at the crud you will get from burning
engine oil. An engine run with a two stroke premix will stay as clean
as any piston engine assuming that the mixture is correct. An engine
with an increased amount of engine oil injected into it will show a
great deal of carbon buildup in just twenty or thirty passes on the
dyno. Yuk!
Paul Yaw
Before you came on on the NL Paul we ran a bunch of test on different
oils in an industrial oven at 500 degrees F. Synthetics were right up
there with two stroke oil and turbine oil. Ordinary engine oil
is about the worse thing you can lube and cool the apex seals with.
There is one other but out of deference to Tracy I won't mention it :-)
BTW Mazda wrote a SAE paper on the apex seal temp verses the apex
seal oil supply. I will look it up for you shortly.
Oh wait here is a chart from that paper.
apextemp.jpg
This is why Mazda injects more oil at high HP. To cool the seal.
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 00:12:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Tracy Crook's
Paul Yaw wrote:
Hi everybody,
I need to contact Tracy Crook. (Good thing he is not a car
salesman!...That goes for Dave Lemon too!)
I need to know what your engine management package is capable of, and
how it works. If it is appropriate for a turbocharged engine, I will
need one within a few weeks. Hope to hear from you soon. Thank you.
Paul Yaw
"Tracy 2 rws@altavista.net" <rws@altavista.net>
Unfortunately I don't think it does. There are others
on the market so check the NL web site.
When you find one that monitors the knock sensors
please let us know.
I need to talk to Abel Ibbarra about what he is using
as he told me he monitors the the knock sensors
closely on his turbo, alcohol and laughing gas 730 HP
turbo 13B drag racing engine.
Abel is using one MSD ignition system for each spark
plug as I recall.
Paul Lamar
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______________________________________________________
Date: Fri, 15 Jan 1999 00:21:24 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
BTW the mechanism is... if the apex seal is cool oil will not
coke in the apex seal slot.
The SAE paper is 860560 Material Technology Development
Applied to Rotary Engines at Mazda.
I hate those long titles :-)
Takumi Muroki and Jun Miyate
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 00:52:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
Here is an old newsletter message on this subject Paul
The date on this was 09/09/98 17:08
--Tracy Crook wrote:
Message text written by Neil:
I have a question for those in the know. What's the optimum ratio for
mixing 2 stroke oil with fuel? I've been using 1 oz / 1 gal but I think
this is on the high side.
Neil
I use 1 oz Marvel mystery oil per gal of fuel which I agree is on the high
side. I hear figures between 3 & 5 oz per 5 gallons of gas from the rotary
car racers.
I just got an RX-7 to drive so I'll experiment on that instead of on the
plane. I plan to tear down the engine (on the plane) and carefully measure
wear at 1000 hours so I'll have a better idea then. Now at 700 on the
Hobbs.
Tracy
Good for you Tracy. You have been doing some flying!
According to SAE paper 860560 Mat. Tech. etc. Mazda recommends 300 cc
per hour at full power to keep the temp down on the apex seals. Since
the tip seal temp can get to 240 degrees C or 465 degrees F. no wonder
oil sometimes cokes in the tip seal slot. Too little oil can cause
cokeing. Ironic is it not?
300 cc per hour is about 10 fluid ounces per hour. The conversion I have
is 0.0338 fluid oz's per one cubic centimeter.
So Tracy burns about eight or ten gallons an hour as I recall and runs
at somewhat less than peak power so he is using about the right amount
of oil. Maybe a little on the low side.
I would not go less than one ounce per gallon. One ounce per gallon is
easy to measure so it is not quite so error prone.
The stock pump puts out .68 to .85 fluid ounces per hour at 2000 RPM on
the early engines up to 1985 according to the Haynes manual and my 1976
Cosmo shop manual.
According to the Mazda rotary engine bible by Yamamoto the ratio at full
power is 1 oz of oil to 150 oz of fuel on the early engines. Since
there are 128 oz in one gallon one oz per gallon is a little on the high
side. Ironically the book shows 50% more oil cruising at 100 MPH. All of
this was probably with the early carbon aluminum tip seals.
The 1986 to 1991 Haynes manual won't say??? The information is missing
for some strange reason. They tell you how to measure it but they don't
say how much???
The early engines only fed oil into the carb. Later engines fed it to
the carb and the housing. The oil injected is not only a function of RPM
but it is also a function of throttle opening.
If I were running it hard I would use two onces per gallon. Other than
cost and oil all over the bottom of the airplane I see no real
drawbacks. (Lower your muffler pipe :-)) Keep them tip seals cool!
I will keep my eyes open on this and see if I can get some later
information.
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 01:44:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: CH601 Zodiac rotary?
Patrick Simpson wrote:
Hi,
I'm considering building a CH601, and I'm looking for about 125 hp to
put into it. Are there any rotary engines out there that are around
that HP, and that weigh less than 260 lbs. with everything on?
Where do the HP and torque curves peak on most rotarys and what do I
need in line of a redrive. Of course that would have to be within the
260 lbs. I know that's asking a lot of an engine, but thought it was
worth a try asking.
Thanks,
Patrick Simpson
Parksville, BC,
currently driving a Challenger II,
The dry weight of a two rotor is about 200 pounds but by the time
you get the rads, PSRU, prop and all it is more like 300 pounds.
If you put the rads in the back of the fuse it might work.
125 HP is no problem. Even with untuned intake and exhaust pipes
you will get more like 150 HP.
They don't really peak. The HP keeps going up depending on porting
and manifold tuning to about 9500 RPM. Most rotaries for A/C use
are tuned for about 6000 RPM.
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 08:49:48 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 900 HP Racing Beat 3 rotor ducted fan airplane.
Jim was a little surprised when I suggested the plugs
up configuration for his 900 HP turbo three rotor ducted fan
engine.
He was unaware that Neil, Ed and others had been successfully
running this configuration for several years.
His reasons for placing the large turbo in the duct
and accepting the duct blockage are the intake is
pressurised to a certain extent by the duct. Two; the
waste heat of the turbo is added to the duct flow
in theory adding to the thrust. Three; the turbo is
cooled in the process. Four; the exhaust goes right
into the duct as well adding additional energy to
the duct flow. Five; the exhaust manifold is short
keeping the energy loss in the pipes minimised.
(That never bothered Orenda with the V8 or GE with the P38,
B17, P47 and other world war II turbo charged
airplanes. I suspect the World War II guys were right.)
IMHO I don't think the increased duct blockage is going
to be worth it so I drew up a plugs up design with the
turbo out of the main duct and into an aux smaller
duct below the engine. The 17 inch dimension is for
the inner "core cowling" and the 28.8 inch dimension
is the inner diameter of the main ducted and is based
on a fan tip speed of 650 MPH at 7500 RPM. I know not
what the real dimensions will be in the actual airplane.
The reason for the plugs up in my configuration
is the engines are to be mounted in pods and there
would be a big bulge on the left engine looking
forward from the rear to accomadate the turbo on an
upright installation. The right engine could have
the turbo located in the aft fuselage with the pipes
running through the pylon. I am really
guessing about all this as I have not seen plans
for the actual airplane.
I had another look at the drain back in the front
housing and it is indeed the least suitable for
a plugs up configuration. It does flow a minor amount
of oil compared to the center housing as all it handles
is excess oil from the front main bearing. The center housing
handles a larger quantity of rotor cooling oil from both
rotors but it is designed such that plugs up should be no
problem.
Never-the-less the separate turbo duct design will
still see dynamic intake pressure and air can be bypassed
to cool the turbo. The exhaust from the turbo can
be used in an augmenter device to enhance the cooling
air flow through the turbo duct. The energy remaining in
in the exhaust out of the turbo should be low at this
point so an augmentor may not work all that well.
The exhaust pipes from the engine and the intake pipes
to the engine can be streamlined within the main duct.
The question is; which system will work better?
Any of you bright people out there want to take
a stab at this?
I think buried engines in a fuselage-blended-wing
design would work the best as there would be room
for the turbos in the fuselage on the right upright engine
and the wing root on the left upright engine.
Perhaps with a canard configuration.
Yet another configuration is place the turbos behind
the engines within the ducts and accept the resulting
long pipe lengths as in the Orenda V8. The exhaust
pipes could be insulated with some miracle material
that would withstand 2000 degrees :-).
Paul Lamar
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______________________________________________________
Date: Fri, 15 Jan 1999 13:06:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
Dale Smith wrote:
Gentlemen, I wish to assure you (from personal flying experience!), that a stopped
prop is MUCH less drag than a windmilling one. (Think "circle of drag") It
remains a very high drag situation, however, with just an (unfeathered, seized)
propeller. So much drag that we were barely able to stay in the air with the
other engine at full METO and indeed, drifted down to ground effect altitudes ...
less than 100 feet above the ocean ... to be able to maintain altitude in an
otherwise "clean" configuration. Aircraft: C-123B enroute to Wake Island.
Engines: 2 Pratt & Whitney R2800, w/ 3 bladed props @15' prop circle, if I recall.
Paul wrote:
Now there is a place you don't want to ditch.
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 13:12:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: ceramic coatings
Alivic@wport.com wrote:
Paul,
I read an article published in Contact last year written by a Chrysler
engineer who alluded to exotic coatings that Detroit was applying to
various components within their engines. I was curious if you believe
that doing a ceramic coating on the combustion surfaces of the 13B
rotors would allow more of the combustion energy to do work or would you
worry that this process would only increase the temperatures within the
rotor housings and exhaust??
I appreciate the work you are doing in making rotary engine technology
available to the masses. Tony Livic
Mazda did some experimenting with this on the Lemans engines.
It payed off as BSFC was very important as fuel mileage
was important in this race. The gains were way down in the
single digit percentasge points so it would not be worth
it for your average A/C engine.
What would be important is a ceramic wear surface coating
that would be durable enough to use on aluminum end housings
assuming one can solve all the other problems with alloy
end housing.
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 17:41:39 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 900 HP Racing Beat 3 rotor ducted fan airplane.
900 HP requires a serious intercooler. Jim is shown holding
the intercooler for the turbo three rotor. Where they are
going to find room for this in the airplane is another matter.
Actully I am pulling your leg a bit. This intercooler is intended
for dyno use only and it is from a 300 HP tractor trailer
truck engine. It will be sprayed with cold water on the dyno
to simulate the intercooler in the airplane.
If it looks a little big for only 300 HP that is because
there is a big difference between 300 HP in a real
truck or aircraft engine and the 300 HP in your Corvette.
The truck engine and the airplane engine has to generate
all 300 horses continuously while hauling 55,000 pounds
over the Grapevine out here is sunny So Cal while only
moving about 45 MPH. Not a lot of air going through
that intercooler at 45 MPH.
The AC aircraft engine is all the more remarkable as it
weighs only about 400 pounds while the truck engine weighs
2000 pounds.
Don't let anybody tell you todays aircraft engines are
obsolete.
The Wankel type rotary engine is equally remarkable.
rbinterc.jpg
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 09:12:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
ingenuir@ix.netcom.com wrote:
facilitator1@juno.com wrote:
EAA test showed that a stopped prop was like getting a boost in airspeed.
Much less drag from a stopped prop, better glide length.
Virgil
Hello, Paul.
When I was looking through von Mises' Theory of Flight for propeller
characteristics and composing my "aero engineer's response" to this
question, I kept striking out the phrase, "But I haven't looked at the
energy extracted from the airstream. Proof can only come from either a wind
tunnel or free flight test." If Virgil can provide the reference, I
respectfully defer to the EAA test.
Careful with the decription, though. A stopped prop is still stopping the
airplane, not giving a boost in airspeed. (Such things are relative ;-> )
Wish I had emphasized more that this was my speculation from the curves.
Gary
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______________________________________________________
Date: Fri, 15 Jan 1999 20:22:26 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Water pump
Gerry Hess wrote:
Paul, the 12A water pump is 19 pounds and the 12A short block without pump
is 190 lbs. I have an aluminum pump outer housing and a cast iron centre on
my single rotor. (vintage 1986 6 port) The centre piece weighs 9 lbs. This
resulted in a longblock minus PSRU of 155 lbs, and total firewall weight of
202.
Even a complete factory aluminum pump is a godawfull abortion and I believe
a pump could be built out of a billet of T6 using only the factory shaft,
bearing, and impeller, that would be lighter and lower for cowling comfort.
I have a thing about modifications. I do them all the time, but always try
to use the stock critical componants as they are time tested and readily
available.
Gerry
Did you see that pump Jim Mederer is using on his three rotor.
He said that pump is the finest water pump he has ever seen.
It is small and compact.
He forgot where he got it but some place in Tenn. sells
it for sprint cars. I have been keeping my eye out for it
as I get Performance Racing Industry mag.
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 13:04:20 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
kwalsh@inhale.com wrote:
The EAA, and CAFE more specifically, tested the stopped prop, versus
windmilling prop, versus the slowly rotating prop on a cessna 152. What
they wanted was a way to measure the drag characteristics of planes without
having the stopped prop problem. The solution was to put a sensor on the
crankshaft that could measure end play (0.002" if memory serves). Using
this sensor they could then adjust the throttle until the propeller was
providing zero thrust. This was correlated by removing the propeller and
replacing it with a tow hook. They then towed the 152 as a glider,
released it, and calculated the drag in flight (by measuring the rate of
descent at fixed velocities).
I am unsure of what the drag difference was between the windmilling prop
and the stopped prop, but I remember the windmilling pro was more drag.
Adding to the confusion-
Kevin Walsh
I want to spool this subject down. Not too important in the
overall scheme of things.
Paul
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______________________________________________________
Date: Fri, 15 Jan 1999 17:02:58 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 900 HP Racing Beat 3 rotor ducted fan airplane.
JBullens wrote:
Paul, I've always been interested in ducted fans.. How far has your research
gone.. I'm more interested in the 13B and ducted fan, but all the
information I can gather, the ducted fan only works well at low speeds of
130 mph or less.. I haven't really kept up with new progress,, can you bring
me up to speed on fan technology. Would love to run a 13B direct to a fan
and run in the 200 mph range.. should be a direct trade off in the weight
department.. Considering the weight of the reduction unit and prop. compared
to the shaft, shroud and fan casting. Plus the canard configuration lends
itself to a fan installation naturally.. But I may be wrong.. Was once but
can't remember when.
Actually it is the other way around. Ducted fans work well at high speed
and not so well at low speed. If you think about it... every time you
fly in a airliner these days you are flying in a ducted fan airplane.
The only difference between Jim Mederer's 900 HP turbo three rotor
ducted fan and a turbofan jet engine is the core engine. The turbofan
uses a gas turbine.
The reason airliners work on takeoff is they have an excess of HP.
Enough HP in fact to go 500 MPH.
Jim is shooting for the same thing. His engines are going in a six
place airplane with a total of 1800 HP. Not your average Piper
Malibu.
Why couldn't you place one large turbo in the fuse with a NASA scoop for
supply and exit to feed both engines supplied by long pipes that will help
cool the intake charge anyway.. seems like some free intake charge cooling
with the long pipes and wisker ducts for cooling that could be ducted to the
cabin for some additional heat. The long run of piping and the natural
cooling the turbo would last longer anyway for the 2000 degree direct pulses of
the engine hence a stock high-performance turbo that would cost less and of
sufficient capacity could be used..
Good idea.
Who is Neil and Ed?
Who is Neil and Ed?!!! You have got to be kidding :-).
Neil, Ed introduce yourselves to the new guy.
Paul
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______________________________________________________
Date: Sat, 16 Jan 1999 00:12:10 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: rotary seal condition & differential cylinder pressure gauges
Gordon Woodard wrote:
Will a differential cylinder pressure gauge work on the rotary ? If so
what pressures are you looking for , the motor is pulled allready and I
would like to get and idea on seal condition before I purchase it
Gordoni
Very good question. I don't know the answer.
Most people use an automotive type compression tester. 85 psi
at 250 RPM is the spec for 1979 to 1991 models.
With a 21 psi allowable difference between rotors.
I have one of those differential cylinder pressure gauges myself.
Never used it on my rotaries and they have been sitting around
so I don't think the numbers I would get now are representative,
Great tool.
Has anybody used an aircraft type differential cylinder pressure gauge
on a rotary?
Paul
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______________________________________________________
Date: Wed, 13 Jan 1999 16:07:16 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Getting your airplane signed off by the FAA
Tracy Crook wrote:
Perry J. Mick wrote:
So now I just decided to sit back and see how long it takes
these bureaucrats to come back with some type of response.
Guess I'd better find out who the local DAR's are.
Perry J. Mick
Mazda 13B-powered LongEz N7XR
Makes you wonder what we are paying these guys for.
Paul
There is yet another level to this game the FAA is playing. Remember that
the DAR positions are handed out to retired FAA types. The FAA guys do not
want to cut into this "retirement benefit" by inspecting your plane for
free. The DAR's typically charge $300 - 500 to bless your plane. I knew
the game from past airplane inspections so I skipped the FAA, called the DAR
& wrote the check.
So do I want to give this wonderful agency more power than they already have
and make the standards for granting an airworthiness certificate more
difficult?
Tracy
I take it that's a NO! :-)
Paul
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______________________________________________________
Date: Sat, 16 Jan 1999 08:58:38 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Who is Neil and Ed?
Neil A. Kruiswyk wrote:
Paul,
It might not be a bad idea to compile a list of who is actually flying
behing a rotary, model of aircraft and first flight date. Total hours might
be interesting but that is dynamic and time consuming to maintain. Pictures
would be a nice touch as well. The list should get bigger and better in the
next few years. I would have done this myself years ago but my ISP doesn't
provide space for web pages.
I'll start it off with myself and Jim.
Name: Neil Kruiswyk neilk@sprint.ca
Local: Near Toronto Canada
Aircraft: Lancair 235
Engine: 4 port 13B natuarlly asperated fuel injected
First Flight: Sep 1988
Name: Jim Mosur jmosur@interlog.com
Local: Near Toronto Canada
Aircraft: Vans RV-6
Engine: 4 port 13B natuarlly asperated carburated
First Flight: July 1998
I'll see about a pic of Jim's plane and send it along.
Now what about Ed, Tracey, Alan and the rest....
Neil
Jim is news to me Neal. Thanks. Good suggestion. When we get
a nice list I will put it on the newsletter web site.
I figured you were too busy shoveling snow up there :-).
BTW Earthlink tech supports Linux as well as Mac and Windows
and gives you a 6 meg web site for $19.95 US.
I have had real good luck so far with Earthlink.
Paul
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______________________________________________________
Date: Sat, 16 Jan 1999 09:08:37 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: End housing repair.
Jim Mederer of Racing Beat designed and built this end housing
lapping machine. If you have a scratched or worn
end housing or center housing call Racing Beat and get a
quote.
Paul
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______________________________________________________
Date: Sat, 16 Jan 1999 09:21:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: IVO root cuffs.
Neil, I just noticed you are running an IVO prop.
Tracy is thinking of fabricating non-structural prop root
cuffs to convert the negative lift coeficient near
the hub to a positive lift coefficent. He mentioned
that to me when I was there at Christmas time.
You and he would probably pick up 10 to 20 miles per hour
when using the IVO prop with cuffs.
BTW is Jim Mosur using plugs up on his RV? Does he want to be
on the Newsletter list?
Paul
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______________________________________________________
Date: Sat, 16 Jan 1999 09:42:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ceramic coatings
Wood Family wrote:
I talked to a guy at Arlington last year that has an amphib. Coot with
a 13B mounted up on a pylon. He runs nitrous
to get a quick boost out of the water and so doing had been
overheating. He said he had his rotors ceramic coated and this brought
his oil temp way down. He also had a stock Mazda oil cooler mounted on
the top surface of each wing with no ducting. I do not recall his name
but could find out if anybody is interested.
Lonnie
Yes I am very interested. I was in Arlington last year
on the first day but i missed it unfortunately.
The no ducting part could be the real problem.
It is probably destroying lots of lift on the wing making
it harder to take off.
If he put them in a better place and properly
ducted them he might not need the nitrous
and the ceramic coating.
See the newsletter web site link list for a desertion
on the proper place and configuration for cooling
ducts.
Thanks for this very interesting information.
Paul
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______________________________________________________
Date: Sat, 16 Jan 1999 10:54:27 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ceramic insulation
Bulent Aliev wrote:
[From Canard Aviators's Mailing list]
I have been using ceramic insulation blankets developed for furnace
repairs for about 15 years. In it's virgin state it's heavy with
whatever liquid they use for curing it to shape. It comes in a sealed
plastic envelope and in varying thicknesses.
I buy mine in half-inch blankets, cut then to shape with ordinary
scissors. I then wrap them around the exhaust system. While still wet,
I make a few wraps of fly screen and finish off with a spiral wound
stainless wire.
The fly screen reinforces the ceramic. It's it cured state it's hard but
somewhat brittle. Since it's not inside a protective shield like a
furnace where it's more commonly used, it runs the risk of breaking. The
fly screen becomes actually imbedded in the ceramic matrix during the
cure. The wire wrap is just to hold things in place until they cure.
You can cure the ceramic by simply using heat from the engine. My
experience has been that while this works OK, you are better off
preheating the material with a high output electric heat gun. You can't
burn this stuff, at least not easily.
I lost the data I stored in my pc but on one engine I did, A
turbocharged Ford V8, the technician had to re-adjust the overboost
values because the inlet side of the turbine was getting significantly
higher pressures. Since the only thing I did was wrap the manifold with
ceramic, the cause and effect are easily demonstrated. The discoloration
in adjacent painted areas has also ceased.
I haven't done this process in about 6 years and some price increase is
to be expected. I'd be very surprised if the entire installation ran you
over $20.oo for a four cylinder engine, ceramic, screening, wire, clamps
and all.
PS: Don't over tighten the wraps or you'll squeeze out the curing
liquid. Just follow the instructions that come with it. Most boiler
repair companies stock the stuff and/or can tell you where to buy it.
ABianconi
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______________________________________________________
Date: Wed, 13 Jan 1999 10:38:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: More drag... prop rotating or stopped?
TERF Email wrote:
For what it is worth anti lock brake theory says that the wheel wants to
be going 85% of what ground speed is for best stop. I imagine that this
would hold true for propellers as well?? If it were spinning at full speed
you would get nothing, faster it would speed up. Therefore it must go
slower to some extent..... The gyro analogy is correct, no spin, very
little drag. Ask anyone who has ever stalled a gyro copter and survived.
For what it is worth.
Matthew Tait
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______________________________________________________
Date: Wed, 13 Jan 1999 16:11:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals? & dyno tuning.
Anderson Ed wrote:
Hi Paul,
I would have been delighted to have my 13B tuned on a dyno and checked
for power output. Considering what I have invested in my aircraft (not
to mention my butt), I would have been delighted to have my engine
dynoed for $750. The problem was I could not find anyone on the mid
east region that could or would do it. Even when I was in the early
stages of thinking about having Mazdatrix build me an engine, Dave
stated he did really want to do the dyno test citing noise created in
the local where he had his shop. The best I could do was give my prop
manufacture the static rpm I could generate on the test stand. He then
calculated that with the specs of my prop the engine would be capable of
producing 165HP. Right now, I estimate based on aircraft performance I
am actually getting around 150hp. But, it was pointed out on this net
that my 2" of foam filter in a 3" dia duct was too restrictive. So, I
plan to fly this weekend with the foam removed and see if I gain about
2-3" of manifold pressure.
If I had had access to the expertise on this list back when I started
the project in 1992, things would have gone much faster and better. I
for one really appreciate the knowledge you, Paul, Tracy and many others
are willing to share.
Ed Anderson
For you new guys its not too late to build your own. Check the NL web
site.
Paul
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______________________________________________________
Date: Sat, 16 Jan 1999 17:52:47 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: IVO root cuffs.
Neil A. Kruiswyk wrote:
Thanks for the info Paul, I'll have a word with Tracey. I like the prop
but I've lost top end with it. I was going to buy a new wood, fixed pitch
one in the spring but maybe Tracey has the right idea.
Yes, add Jim. He's running plugs up.
Neil
You too eh? Don Bates predicted that with his prop optimiser program
and now we have several confirmations. See the web site link list for
his email address.
Paul
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______________________________________________________
Date: Sat, 16 Jan 1999 23:32:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
CC: Dennis Simanaitis <enged@aol.com>
Subject: Take off monitor.
I was wrong about a few things in my last article
on this subject. The Voyager was never tested with
full fuel and my test equipment did not make
the cover of that issue. It was the center spread.
Dennis Simanaitis was kind enough to dig up an orginal
copy of the May 1987 issue of Road & Track complete with
all cardboard and send it to me.
Thank you very much Dennis.
Hopefully I can convince Tracy to add a takeoff monitor,
using the same software technology used in this Lamar Instrument
test equipment, which was used to test the Voyager, to
his EFI instrument panel display computer.
Here is an excerpt from R&T page 53. The article was written
by Peter Egan and the photo was by John Lamm.
Note how close the left wing tip is to the ground.
"opened its throttles and rolled down the pavement. The wings went
from full droop to upswept arc, the Voyager gathered speed and- And
left the pickup in the dust. The truck couldn't keep up. It stayed
with the airplane up to about 60 mph, then the Voyager simply
pulled away, rotated skyward and flew off on Test Flight Number 48.
"We didn't anticipate how quick it would be on the top end," Glenn
Maben said later. "Maybe next time you should bring your Corvette."
Which we did. Five more times, five more lovely desert sunrises
and test flights, from September through early December. There was a
ground acceleration test where the Voyager cooked its front brake
trying to stop 5600 lb of fuel at the end of the runway while Glenn
tried to slow it down by grabbing the Voyager's tail from the
Corvette window. The airplane did the quarter mile in 26.5 seconds
at 42 mph on that run.
Near the end of September, on Flight 51, the
1858 lb craft (empty) lifted 3600 lb of fuel off the ground while
turning in a 25.5 sec quarter mile at 63.7 mph, and a 0-60 time of
23 sec. On that flight I had my first truly vivid insight as to the
seriousness of what Rutan and Yeager were doing. On the takeoff
roll Glenn was driving the Corvette, tucked in just behind the
Voyager's right wing, and I was in the passenger seat, my elbow
sticking out the open window, cruising style. As we hit 70 mph on
the runway I watched that long, gasoline filled wing flex and
shimmy in front of our windshield and suddenly realized that if Burt
Rutan had been a few notches off on the old slide rule, or if
brother Dick didn't live up to his "velvet arm" flying reputation,
we'd be swimming in a few hundred gallons of gasoline before you
could say melting fiberglass. Almost with a will of its own, my
left hand crept over to the center console and hit the electric
window lifts. Closed. Glenn watched the windows go up and grinned.
The slide rule and the velvet arm came through, however, and the
Voyager rose gracefully from the runway.
These are very brave
people, I thought to myself. Armed with the latest acceleration
data, I went back to the office and checked the R&T test archives
for performance comparisons with cars. (This is a car magazine,
after all, and we've gotta tie it in somehow.) I discovered that the
Voyager was almost exactly as fast in the quarter mile as an MG-TC,
but not quite as quick. In all fairness, however, it should be noted
that the TC could carry only about 16 gal. of fuel, versus the
Voyager's 590 gal., on this particular run. Also the TC ran out of
steam at 75 mph, while the Voyager's average speed for the world
flight was 115.8 mph, and at one point it hit a 165-mph ground
speed, with tailwind. Voyager's around-the-world mileage was 21.0
mpg, a little worse than the 23.6 mpg I recorded on my last
cross-country TC trip, but then the Voyager is capable of 50 mpg
when nearly empty as opposed to a TC best of about 26 mpg."
End of quote.
Paul Lamar
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______________________________________________________
Date: Sat, 16 Jan 1999 23:44:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ceramic coating 13B powered Coot
Wood Family wrote:
Paul,
I just called a guy that is building a Coot with a 13B that know the
other guy with the Coot that has ceramic coated rotors.
His name is Ken Welter and his phone number is 360-834-4089.
He does not have a computer. At Arlington he was very open
and willing to talk about his experience with the 13B.
He has been flying his plane for a number of years and has some good
stories to tell.
On one occasion the spring disk from his Ross re-drive flew apart, came
out the side of the drive and put holes in his wing.
He said he has solved this by putting on a heavy flywheel, 35 lbs. if I
remember right.
I think he did not get to Arlington until Friday so that's why you
missed him.
Lonnie
Thanks Lonnie.
Thats the first I have heard of one of those clutch disk comming
apart. He may be running a 3:1 Ross PSRU and he has higher
than 6000 takeoff RPM. He has a strange way of solving problems:-)
BTW could you turn your word wrap on or
use shorter lines. Which email program are you using?
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 16 Jan 1999 23:54:55 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Tracy Crook's EFI system and turbo's
Tracy Crook wrote:
My EFI/ ignition controller is OK for turbo installations with up to 25
inches of boost if ordered with the 2 BAR MAP sensors. Naturally it will
require injectors with sufficient flow rate.
Tracy
rws@altavista.net
Tracy, please add your email address to your signature.
Will save me a lot of work :-)
After I get you to add that takeoff monitor I am going
to start working on you to add a knock sensor :-)
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 16 Jan 1999 23:50:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ceramic coating 13B powered Coot
If Lonnie can't get ahold of him , I may be able to. He belongs to our
local PRA club (chapter 73) and most always flies his Coot to the
meeting. Other than Everett Hatch, this is the only 13b I've seen in the
air.
Phil
Lonnie found him Phil thanks.
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 00:44:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ceramic coating
This is a jpg of a paragraph from "Mazda 4-Rotor Rotary Engine for the
Le Mans 24-Hour endurance Race. SAE paper 920309
One must differentiate ceramic coating for wear reduction and
ceramic coating for heat insulation.
No where in this paper did Mazda mention any heat insulation
or fuel consumption advantages or lower oil temp advantages
of ceramic coating. It was done strictly for wear reduction
and even then it was a less than a 15 percent improvement
over a nitrided cast iron.
The down side is you risk exfoliation with probable serious damage
to your engine.
Not only that Mazda used the very expensive "detonation gun"
technique to apply the coatings. Not your average hot rod
technique. On alloy housing you have no choice. You have
to use ceramics.
In short... save your money or put it elsewhere to improve
the rotary such as ceramic tip seals.
Sorry about the jpg. My OCR does not work too well with
these bad copies of SAE papers.
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 08:38:14 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: HP and torque curve differences
BCGARDNER@aol.com wrote:
Paul,
Can I ask you a question that isn't strictly a rotary related one?
It relates to the difference between aircraft engines and auto engines in
where they develop peak horsepower and torque.
I was out running the pattern yesterday in a C-172 and its four cylinder
Lycoming O-320-E2D is redlined at 2700 rpm, where it develops 150 BHP when in
tune and in like-new condition. And of course we know that one of the great
advantages of such rpms for aircraft is that you want to keep your prop tip
speed below supersonic in order to maintain prop efficiency (though it seems
like air racers regularly crank up the rpms quite a bit).
I'm also the proud owner of a Dodge chassis motor home that has the venerable
eight cylinder Chrysler "A" small block 318 cu. in. engine in it, which also
develops 150 BHP-but at 5000 rpm.
So, of course, every guy that's thought about putting an auto engine in an
aircraft wrestles with the best way to keep the rpms down via some kind of
reduction drive-geared, belt, chain. And some people, like Steve Wittman, put
in an auto engine, ran it direct drive and just accepted the lower HP
available at aircraft-type rpms.
My question is: What are the engineering differences that make or allow the
320 cu. in. Lycoming to develop its horsepower at lower rpm? Bore and stroke?
Camshaft profile?
Or is the Lycoming somehow a more efficient /more powerful engine in which we
have truncated the HP curve by running it at lower rpm in order to increase
its reliability? What would the Lycoming put out at 5000 rpm? And would the
cost of that simply be a reduction in TBO?
Please don't get alarmed here. I've never even thought of putting a really
heavy small block Chrysler in an aircraft; I'm still devoted to my Mazda 13B.
But I thought it was a near-perfect example of two comparable displacement
engines that developed the same HP at different rpm ranges.
I'm a financial guy, so this question takes me beyond my self-taught shade-
tree-mechanic engineering expertise. I'm still working on filling in the gaps
in my education.
Thanks.
Barry Gardner
I think this is a very good article Barry and you have brought
up some very good points.
In a word breathing. Not only the cam but the exhaust and the intake
of the aircraft engine is optimised for 2700 RPM as well as the
structure.
The Chrysler was orginally designed to generate a lot more HP as a car
engine. Chrysler decided to limit the breathing by installing a cam & a
small throat diameter carb. They did this to limit the HP and extend
the life of what was basically a car engine for use as a light duty
truck engine. There may be other heavy duty changes in the engine
as well such as a forged crankshaft rather than cast iron and higher
quality exhaust valves. (The Lyc has very expensive sodium cooled exhaust
valves indeed, currently running about $250 to $300 each.)
Other changes may have been made to the Chrysler such as forged pistons
instead of cast.
The automotive state of the art today is... the manufacturers are much
better at making a product whose cost is matched to the end use.
In other words there is not one bit of excess cost in a car engine that
does not need to be there given the worst case use that 90 or 95
percent of the buyers will put it too. That means an average HP of somewhere
around 30 to 40 HP for a car engine and 40 to 100 HP for a light duty
truck engine such as the Chrysler you mentioned. Minor changes in these
numbers can occur over long periods of time.
Even in Germany, where
most speeds on the autobahn are unlimited, manufactures, such as Mercedes
and BMW, are intalling speed goveners to limit the top speed to 150 MPH
and hence the continuous HP required. HP required is roughly proportional
to the cube of the speed. There are other factors at work in Europe
to limit high HP use such as traffic and short distances.
Another trend is to monitor the engine temp, RPM and one or two other
factors with the engine computer and shut down the fuel supply or
ignition timing to limit the continuous HP used for warrantee reasons.
By this method too a lower cost engine can be built.
Robin and I helped test the last generation Corvette at Willow Springs
for Popular Science. We were in a convoy with six other sports cars and
Robin was driving the Corvette. She inadvertantly left it in a lower gear
too long and the computer shut down the engine on her. It was a
preproduction engine so the software may have been changed since then.
Now to answer your question about the Lycoming. It would put out a bunch
of HP for a short period of time but would soon blow up because the structure
was specifically designed for 2700 RPM.
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 11:30:59 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Coot Redrive
Wood Family wrote:
Paul,
If I remember right Ken Welter Is running a reduction of 3.7 or 3.8 to 1.
When I told him I had built my drive at 2.48 to 1 he claimed I would
never get it off the ground.
I am using Internet Explorer, I think it is version 3.?
If there is a way to turn on wordwrap please let me know.
I did download the latest I.E. version but it is just too slow on this old computer.
Let me know if these shorter lines are any better.
Lonnie
rwood@iceinternet.com
This message seems OK Lonnie.
I don't run Internet Exploader so I could not tell you :-)
I run Netscape.
As far as getting off the ground what airplane are you putting it in?
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 11:33:04 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ceramic insulation
Archie Frangoudis wrote:
In essence, when reading your ceramic insulation messages, I was reminded of
the use we have in Combustion chambers and Piston tops. It does not last as
long in Nitromethane fueled engines, and is being abandoned by some. It is
largely used as a heat barrier rather than wear protection in this case.
Previous message: I build drag and circle track racing engines, and have found measurable
increases in engines that have had their exhausts thermo wrapped. (not pretty, but effective).
It is most significant in turbo'd engines with improvements in throttle
response and HP showing up on the dyno.
Archie
This we can read Archie. Thanks.
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 11:36:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: What happens to the apex seals if the engine stops while
flying.
TerryBuild@aol.com wrote:
From my experience starting at 800' agl during the slightly more than one
minute to the ground, the prop did not windmill. Apex seals are cheap
compared to .............!
Thank you for the interesting discussions. I will try to inject comments from
my experiences as appropriate. Nice to hear from Neil again.
Engine mount tubing - I used 5/8 .049 wall and it meets the crash test.
Terry, care to share more details on that crash? What kind of engine
and airplane? what happened? Hope you did not get hurt.
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 15:52:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: HP and torque curve differences & book list.
BCGARDNER@aol.com wrote:
Paul,
Thanks for the explanation about the effect of changing the breathing on an
engine. I thought that might be the direction your answer would take, inasmuch
as I had taken that Chrysler 318 and made a few changes on my own. I replaced
the OEM 2 bbl carb with a Carter 4 bbl AFB, put on an Edelbrock dual plane
manifold, put on tube headers, and full dual exhaust with a crossover pipe.
Though the motor home weighs 10,000 lbs, it does demonstrate more oomph using
the seat of the pants G meter though it sounds as though I may have shortened
my motor home's TBO.
One follow-up question: What effect, if any, does it have to be a four
cylinder vs. eight cylinder engine with the same displacement?
Well for cars smoothness is highly valued so eights are smoother than
fours. Eights burn more fuel for the same power than fours. More internal
friction. For the same displacement you can get more power out of an
eight because you can turn it faster for the same internal stresses.
And of course eights cost more than fours.
I've never really pursued this question for aircraft engines before, though
I'm aware that big one-cylinder dirt motorcycles (say, 500cc in a single
cylinder) are supposedly renowned for torque. Is it the size of the fuel-air
charge being burned all at once?
Generally you can more low speed torque with fewer cylinders. Why I
don't know.
In aircraft engines, you have to go to about 180 HP before you see six
cylinders (a la the Franklin or, a bit more powerful, the Continental). And in
spite of the history of high output four cylinder auto racing engines (Offys,
for example) most auto magazine writers are pretty skeptical when they review
a tweaked four cylinder engine compared to a six cylinder alternative.
So, the financial guy (me) puzzles why supposedly knowledgeable auto writers would be
so disdainful of four cylinder auto engines when four cylinder aircraft
engines are very typical and very reliable.
There is a limit to the bore of about 5 or 6 inches for an aircooled
cylinder. Really big... air cooled cylinders don't cool well. If you cannot
get enough power out of four five inch cylinders you go to six or up to
forty eight five =13inch cylinders.... =14the corncob engines used in B36
and other large piston engine aircraft.
One of the disadvantages of having virtually only two aircraft engine
suppliers and the FAA's making it difficult to change certificated aircraft is
that nobody talks much about these engineering trade-offs except people
interested in experimentals. And financial guys trying to learn more about
engineering.
Thanks. I'll return the favor if you have a business you need to value
someday.
Barry Gardner
Looks like it is time for my book list again.
* I can highly recommend a book by Herschel Smith called "A History
of Aircraft Piston Engines" published by Sunflower University Press
Inc. 1531 Yuma, Manhattan, Kansas 66502-4228. ISBN 0-07-058472-9.
629.134'352 in a good library. This is a reprint of a book
originally published by McGraw Hill in 1981. Fourth printing 1993.
There are 250, 8.5 by 11 pages. It chronicles the evolution of the
aircraft engine from early days to the present. There are many
tables listing every engine ever put in an airplane with all
important specifications including weight, horsepower, RPM,
configuration and in some cases BSFC. There are many photos and
drawings of all types of aircraft engines. This is as close to a
bible of aircraft engine history that I have found so far. About
$22.
* Schneider Trophy Racers by Robert S. Hirsch. Motorbooks
International Osceola WI. Excellent history of the water cooled V12
leading up to the Merlin. Lots of good drawings done by the author
and photos.
* Thompson Trophy Racers. Roger Huntington. Motorbooks
International. 1989 ISBN 0-87938-365-8. $19.95. 8.5" by 11" 188
pages. Fascinating reading. Lots of good mechanical drawings, photos
and cut-aways on aircraft engines plus a good history of the
development of aircraft engines for air racing.
* Allied Aircraft Piston Engines of World War II by Grame White
published by the Society of Automotive Engineers, Inc. 400 Copyright
1995. Commonwealth Drive Warrendale PA 15096-0001 (412) 7765 4841
Fax (412) 776 5760 8.5" by 11" hard bound 400 pages. ISBN 1-56091-
655-9. Lots of good drawings, excellent cutaways and illustrations
as well as photographs. Surprisingly not technical despite the
publisher. This is a well researched book with extensive references
but rather disappointing to me as I would like to see a lot more
technical information about power curves verses BSFC, engine
weights, TBO's and such. I expected a lot more from the SAE.
Therefor this expensive book is NOT recommended.
* Smithsonian Air & Space magazine article "Power Struggle" by Don
Sherman, January 1997, page 72. Excellent ten page article (with
many pictures) about auto engines in airplanes. A brief history of
all auto engines in airplanes and a more detailed history of the
twenty year, twenty million dollar development of the Chevy V8
based, all aluminum Orenda liquid cooled aircraft engine. At this
time (Jan 1997) and well after the article was written the engine
failed its FAA 150 hour full power certification test due to a
crankshaft problem after 20 years of very expensive development.
Extensive changes have been made to the basic Chevy big block engine
including a parallel cooling system with dual coolant pumps as
opposed to the serial cooling system with single pump as typically
found in automotive engines. Parallel cooling systems were
considered to be essential in the 1920's on liquid cooled aircraft
engines.
Engine length is almost everything to a car designer. Engine cooling
compromises are made by simezing the cylinder walls in automotive
engines. Crankshaft life at high continuous power is compromised by
shortening the length, leaving too little room for adequate size
journal fillet radii. In my opinion this engine will not be
successful until it is re-designed from a clean sheet of paper to be
a real aircraft engine. If that happens they might as well go to a
horzontal opposed configuration for lighter weight.
Orenda is now in the process of moving the project to Nova Scotia
and injecting another 32 million dollars of mostly Canadian
government money.
"Those that fail to learn from history are doomed to repeat it."
* Sky Ranch Engineering Manual. This book presents an excellent
overview of the problems of aircraft engines. It is 500 pages and a
bargain at only $23. There are many details on the materials and
processes used to build a successful aircraft engine. There is a
very good and exhaustive discussion of destructive torsional
vibrations and fatigue. The telephone number to buy this book is
(916) 421 7672. The author is John Schwaner. John is highly thought
of in the experimental aircraft community.
* For those of you with an engineering degree or equivalent Taylor's
series of books is the best there is. The bible of engine design.
The Internal Combustion Engine in Theory and Practice.
Volume 1: Thermodynamics, Fluid Flow, Performance. Second Edition
Revised.
Volume 2: Combustion, Fuels, Materials, Design. Revised. Charles
Fayette Taylor. The MIT Press Cambridge Massachusetts, and London
England. AutoBooks in Burbank CA.
* Introduction to the Study of Aircraft Vibration and Flutter by
Robert H. Scanlan & Robert Rosenbaum, Dover Publications touches
on crankshaft design. Lib Cong 68-22341.
* The definitive book on the rotary is simply called "ROTARY ENGINE"
by Kenichi Yamamoto published by Toyo Kogyo Co. Ltd. (Mazda) in
1969. This is a highly technical book chronicling the development of
the wankel by Mazda. Kenichi is an engineer and has risen to CEO of
Mazda.
* Another technical book on the Wankle rotary engine is; "The Wankel
RC Engine Design and Performance" by R.F.Ansdale Published by A.S.
Barnes & Company Lib of Cong 69-18692
* The Wankel engine Design Development Application by Jan P. Norbye.
Chilton Book Company. ISBN 0-8019-5591-2 Published in 1971. A little
history and results of the Wankel engine development by NSU,
Mercedes, Mazda and others and some results of work by
Curtiss-Wright. Also some history on all rotary engines. Not as
technical as I would like but not bad.
These books will be easier to find then the Toyo Kogyo book.
* Curtiss Wright published quite a few SAE papers back in the 60's
and 70's on their development of the rotary for aircraft use.
* The development of Piston Aero Engines by Bill Gunston 1993, 1994,
1995. ISBN 1 85260 385 2. Patrick Stevens Limited/Haynes Publishing
Sparkford Nr Yeovil, Somerset, BA227JJ. Hard bound 213 pages. $39.95
at the Wright Pat Airforce Museum.
The first half of the book is on basic principles and engine design.
For the most part this is very well done for the non-physicist
non-engineer reader.
The middle is a history of of the development of aircraft engines.
The author criticizes Fiat compared to Rolls-Royce for not
developing high HP per cubic inch while still acknowledging that the
V24 Fiat powered Macchi MC.72 still holds the world's seaplane
record set in 1934 at 440 MPH! Sounds like a little British Empire
envy to me. HP per cubic inch is irrelevant when it comes to
aircraft engines. What really counts is continuous HP per pound and
continuous HP per square foot of engine frontal area. There is no
replacement for displacement.
The last chapter; "Chapter 8 Piston Engines Today and Tomorrow"
categorizes engines by air cooled, liquid cooled, diesels and
unconventional. All engines are included world wide no matter how
obscure starting with low power engines for ultra-lights through
auto engine conversions. The major fault with this chapter is all
engines are listed from PR information regardless if they have flown
or even run for that matter. Teledyne Continental is given almost
equal weight with TTL (UK). Ever hear of TTL (UK)?
In the case of auto engine conversions he quotes Blanton with his
Ford V6 powered Cessna 175 that supposedly cruised faster than the
GO-300 (geared opposed) model and unrealistically burned 6.8 gallons
an hour (90 HP at 0.45 BSFC) instead of 12 gallons per hour for the
GO-300 (157 HP at 0.45 BSFC) without checking the numbers. Bill
Gunston should know better.
I think Bill Gunston is a little gullible. Other than that the
book seems to be excellent.
* SAE Paper # 871042 0148-7191/87/0428-1042 $2.50 Design and
Development of the Voyager 200/300 Liquid Cooled Aircraft Engine by
R.E. Wilkinson. Twenty pages. Published in 1987. This paper is about
the engine used in the Rutan Voyager around-the-world un-refueled
record holder. If you never read anything else about any kind of
engine you must read this paper. It is by far the most informative
and up to date information on liquid cooled engines there is.
The real critical limitations of the aluminum head engine are
thoroughly explored. That is; the temperature of the metal
immediately adjacent to the combustion chamber. Aluminum loses half
of it's fatigue life when the temperature goes up from 250 degrees
to 500 degrees F. Therefor this temperature limits the amount of
continuous power obtainable from any engine whether air-cooled or
liquid cooled. Just because the coolant temp. is less than 220
degrees F does not mean the metal next to the combustion chamber is
anywhere near that at high power levels. The continuous HP
requirements are far higher for an aircraft engine than they are for
an auto engine or pickup truck engine.
The Automotive manufacturers rarely publish any real information
about engines in the SAE due to the highly competitive nature of the
automobile marketplace. This paper is an outstanding exception for
the SAE. A must read bargain of real information.
* SAE Paper 690302. Designing Cast Components for V8 Engines. J.L.
Fitz et. al. Central Foundry Division of GM. Written before GM
clamped a lid on all real information published by their engineers
in the form of SAE papers. This paper is about the trials and
tribulations of making an engine work as designed by the stylist
and using chewing gum materials as specified by the bean counters.
* SAE paper 841221 Development of Powder-Forged Connecting Rods
by K. Imaahashi, C. Tsumuki, & I. Nagare. Toyota Motor Corp.
The conversion of Kg/mm^2 to P.S.I is by multiplying Kg/mm^2 by 1.45.
The Toyoto rods, according to this paper, are about as good as forged
SAE 10L55. Aircraft engine rods are made from forged 4340 which has
at least a 25% better fatigue life than forged SAE 10L55.
* Photo-Elastic Analysis by A. W. Hendry, Pergamon Press investigates
stress concentrations in complex machine parts such as crankshafts
and connecting rods. Lib of Cong # 65-29062. Only recently has
computer finite element analyses developed to the point of
perhaps doing a better job on crankshafts than these techniques
invented in the 30's. The book has a great bibliography on the
subject.
* V-6 BUICK FORD & CHEVY 90 deg./60 deg. Performance. by Pat Ganahl
CARTECH 1988 ISBN 0-931472-13-X $18.95 I normally don't recommend
books of this genre as they do not have the detailed and factual
engineering information such as BSFC, stress and heat rejection
information necessary to successfully adapt and auto engine to
aircraft use. What this book does, in it's introduction and
crankshaft chapters, is discuss the myriad compromises that led to
the 90 degree V6 auto engine.
The real reason such a fundamentally mechanically unbalanced and
problematical design is used in cars is revealed. I.E. the properly
designed, high displacement, 60 degree V6 is too tall for modern car
styling and the 90 deg. V6 can be made on the same production line
as the V8. Consider this book one that should be read on why you
should not put a 90 degree V6 in your airplane. Besides, all V and
in-line engines are trying to jam their crankshafts out the bottom
of their blocks anyway. This is one of the reasons they are
inevitably heavier than opposed engines.
* Hotrod Magazine. GEN III. The first look at the all new GM
small-block V8 LS1. By Jeff Smith. Page 50, September 1996. Normally
auto magazines do not publish the material specifications for auto
engine parts. This article on the AL alloy block Chevy V8 LS1 engine
is an exception. Crank, rods and main bearing caps are specified as
either cast iron or powdered metal. Chevy actually went down on the
valve stem diameter to reduce the valve weight. This is not what is
needed for good heat rejection in high duty cycle engines. Lots of
other engine details are included.
* Metallurgy Fundamentals Daniel A. Brandt The Goodhart Willcox
Comp. Inc 1992 ISBN 0-87006-922-5 Lib of Congress 91-22280 Lots of
data on heat treating, hardness, properties of steel, crystal
structure, failure & deformation, microscopic structure, surface
hardening, etc. and stress.
* GM Performance Parts 1997 Parts Catalog. $6.95 at your friendly GM
dealer. GM may put chewing gum cast iron and powdered metal parts
in their light duty engines installed in their passenger cars and
trucks but they will be glad to sell you the 4340 chrome molly good
stuff in the parts catalog. Of course all other manufactures are
putting chewing gum parts in their passenger car engines as well. I
am not singling out GM.
I have nothing to do with any of these publishers.
Feel free to send this list of books and papers to anyone who may be
interested in engines.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 16:00:05 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: HP and torque curve differences
Marvin Kaye wrote:
Hi Paul,
I noticed your comments to Barry about the Lyc/Chrysler comparison, very
interesting...
In a word breathing. Not only the cam but the exhaust and the intake
of the aircraft engine is optimised for 2700 RPM as well as the
structure.
I was under the impression that a lot had to do with the bore and stroke as
well... the auto engine probably has a smaller bore and uses a long stroke,
where the Lyc has a pretty large bore and uses a short stroke. Is this not
true?
<Marv>
Big bore short stroke helps the breathing as you can get bigger valves
for the same displacement or engine weight.
The over riding thing to always remember is:... HP per pound of engine weight
is way more important than HP per cubic inch. Only in car racing
does HP per cubic inch matter.
Here is another place where the rotary engines shines.
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 15:54:16 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Coatings Resources]
StJames515@aol.com wrote:
Hi Paul,
With the thread going on ceramics and coatings, I though some would be
interested in a list of sites on these ideas that I have collected over time.
Try the first site --TechLine as they have a good FAQ page for "automotive"
use. Their products can be ordered from a dealer, powerhouseproducts.com
I hope these resources will help someone
Tommy James
http://www.goracing.com/techline/index.html
http://www.hpcoatings.com
http://www.zypcoatings.com/
http://www.vaportech.com/noframes/auto.htm
http://www.cyberhost7.net/performa/index.html
http://www.airborncoatings.com/index.html
http://www.swaintech.com/sindex.html
--
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 17 Jan 1999 16:02:26 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Water pump weight and FWF weight for rotary.
Tracy Crook wrote:
Gerry Hess wrote:
Paul, the 12A water pump is 19 pounds and the 12A short block without pump
is 190 lbs. I have an aluminum pump outer housing and a cast iron center on
my single rotor. (vintage 1986 6 port) The centre piece weighs 9 lbs.
This resulted in a longblock minus PSRU of 155 lbs, and total firewall weight of 202.
Even a complete factory aluminum pump is a godawfull abortion and I believe
a pump could be built out of a billet of T6 using only the factory shaft,
bearing, and impeller, that would be lighter and lower for cowling comfort.
I have a thing about modifications. I do them all the time, but always try
to use the stock critical componants as they are time tested and readily
available.
Gerry
19 pounds! Yikes! Another reason to choose the 13B instead of the 12A. I
just measured the 13B pump including housing at 8.75 pounds(1988 model).
Sounds like the 13B block is a bit lighter too. Mine was 180 as I recall.
My FWF weight is 340 pounds (everything except prop). Compare this to a
typical 0 - 320 installation (on Cessna 172 or similar) at 355 to 385. I
was able to find 3 examples that people had actually unbolted from the plane
and weighed. The Lycoming book lists the total engine weight as about 276
pounds but that does not include a lot of stuff found in a typical engine
installation.
Tracy
--
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______________________________________________________
Date: Sun, 17 Jan 1999 16:12:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Tracy Crook's EFI Installation and Tuning guide
Tracy Crook wrote:
Paul Yaw wrote:
Hi everybody,
I need to contact Tracy Crook. (Good thing he is not a car
salesman!...That goes for Dave Lemon too!)
I need to know what your engine management package is capable of, and
how it works. If it is appropriate for a turbocharged engine, I will
need one within a few weeks. Hope to hear from you soon. Thank you.
Paul Yaw
Paul Yaw, if you will send me your snail mail address I'll send you the
installation and tuning guide for the engine controller I make. That is
probably the best way to get an idea of what its about. I haven't tried it
but I doubt that it would work very well on an automotive application.
Boats and airplanes would work fine with it though.
Tracy Crook
"Tracy Crook" <rws@altavista.net>
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______________________________________________________
Date: Sun, 17 Jan 1999 20:59:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake and Exhaust Manifold Tuning
V. E. Welch wrote:
Thank you for the information. You said in your reply:
If you have room a rolled up exhaust manifold/muffler will work.
Again there are plans on the NL web site. >
I took a look at the sketch an have a couple of questions. Is there
anything inside of the muffler or is it just a hollow 6" tube with the ends
welded closed and the inlet and outlet pipes welded to it? How should this
be modified to accept the turbocharger? Would you recommend inconel for the
tube and stainless for the muffler or should the entire assembly be inconel?
Vince
Yes! Quite empty. You won't need it with a turbo as a turbo extracts
so much energy from the exhaust it is quiet enough.
Just a function of cost and weight. If you make it all out
of Inconel you can use 0.049 and it will weigh less.
If you use 0.049 Inconel down pipes and 0.065 ss can and exhaust
pipe it will be heavier and cost less.
If all 0.065 ss it will cost even less and be even heavier.
In other words mixing and matching is acceptable if you find the
right welder.
Paul
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______________________________________________________
Date: Sun, 17 Jan 1999 21:13:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Compact Intake Manifold
V. E. Welch wrote:
Paul,
I was just looking at your intake manifold sketch on your site. Is there
any material specification for the tube that encloses the intake tubes?
The subtle beauty of that design is the rolled up tubes act as ribs
so 0.040 aluminum can be used as a plenum chamber and wrapped
around the tubes. If this was not the case the plenum would collapes
if the throttle was suddenly closed due to a high vacume in the
intake manifold. The end of the tubes should be flared slightly.
The end covers should be dommed by hamering
over a wood block form or spun on a lathe. 6061-o should be used
for the ends and 6061 T6 for everything else as 6061 is a
weldable aluminum alloy.
On your muffler sketch you gave an O.D. of 6" but no length is mentioned,
does it matter or can any convenient length the fabricated?
Thanks,
Vince
Any convient length with about an eight inch minimum.
BTW I will advertise these on here for free
if you wish to make up several for sale.
Perhaps Paul Yaw or Matt would like to test these on his dyno so
a prototype might be wise.
Paul
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______________________________________________________
Date: Sun, 17 Jan 1999 21:29:24 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Plane for reduction drive.
Wood Family wrote:
Paul,
My 2.48 to 1 reduction drive is going in a Wag Aero Sportsman.
The plans call for any where from 125 to 180 H.P. Empty weight
is 1100 and gross is 2200 lbs. I carved a
75-60 prop for it. According to my calculations this should keep
the prop tip speed below 80% mach at a reasonable rpm. I think
I was figureing on 6500 but it has been a while.
Excellent! 6500 RPM will buy you quite a bit more power.
2.48 to one is almost ideal for that type of airplane.
The only thing better would be a variable pitch prop.
How wide is your chain?
On the spring disk comeing apart in a ross re-drive I have heard
of others developeing cracks and advice was given to change
them at 1000 hrs. On my drive I have used a heavy duty truck
clutch disk but I am not sure it was really necessary. It is believed
that the Hi-Vo chain takes care of the torsional vibration thru the
dampening effect of the chain throwing out in an arc.
Lonnie
rwood@iceinternet.com
I would stick with the disk. Tracy has at least 650 hours on his
disk and maybe 900 if he did not change it when he sent the PSRU
back to Ross for overhaul at 650 Hours.
Did you change that clutch disk Tracy?
Other people have not reported any failures so far as I know.
As I recall the ones I saw were Ficthel(s) and Sachs(s) and
probably came from a high power BMW manual transmission car.
Paul
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______________________________________________________
Date: Sun, 17 Jan 1999 21:44:48 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: HP and torque curve differences
facilitator1@juno.com wrote:
HP fine Torque important. Older cars & Aircraft use
big bore, long stroke. Long stroke =large crank
radius=twist power.
Short stroke small bore = more hp &rpm to get same
thing. RPM important therefore PSRU used+weight
penalty. Are we making progress ??
Rotary Rules !!
Virg
Terse!
P
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______________________________________________________
Date: Sun, 17 Jan 1999 21:41:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Sleep.
Archie Frangoudis wrote:
Paul, I have been on this rotary site for about a week now, and being a
neophyte in the rotary realm.
(most of my product is between 800 and 5000hp)
Every time I check in to see what's new, you are there.
Do you ever sleep?
Archie
Off and on :-) I do odd jobs around the house and drive up
to the hangar 60 miles away. Yesterday I put new front brake pads
in the Cougar at the hangar.
This week I hope to install the new engine in the 182 if
I finally get the throttle, prop and flap control
cables I ordered from AC Spruce.
Paul
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______________________________________________________
Date: Sun, 17 Jan 1999 21:43:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Tracy Crook's EFI Installation and Tuning guide
facilitator1@juno.com wrote:
Tracy, What eng for KR-1??
Original was 36hp WV. Then went to 2100cc
turbo. Like to keep it to 40/65hp.
THX, Virg
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______________________________________________________
Date: Mon, 18 Jan 1999 07:16:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 900 HP Racing Beat 3 rotor ducted fan airplane.
Richard White wrote:
Paul wrote:
If I were doing it this is the way I would do it.
Jeez, you must have been reading my mind. That's eerily similar to my
plan for a single engine high speed ducted fan. Except my intake and
exhaust runs are bit shorter, as allowed by the shape of the fuselage at
that point. And my engine cooling goes on the spark plug side to
balance it out.
Happy Times Upon You,
Richard.
There is usually only one right way :-)
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 07:33:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Free cooling calculations spreadsheet.
Anderson Ed wrote:
>
> Paul,
> I have worked up a spreadsheet that provides:
> 1st Order Estimates (calculations based on energy content of fuel) of
> power for 1,2,or 3 rotor engines as well as cooling requirements at
> those by horse power produced. You can change A/F ratio, Rpm
> range/increments, throttle setting, altitude Sea-level/8000 MSL, and OAT
> temp (determines air density) as well as fuel injection subsystem
> parameters.
>
> The results are Horsepower by rpm, fuel burn, BTU rejection needed thru
> radiators and oil cooler (and it does calculations for injector timing
> as well).
>
> It is not a Load compensating simulation but simply a set of
> calculations, but it appears to give within first order approximation
> the power outputs being reported. Sort of fun to play with in any case.
>
> I removed the oil cooler part as it was germain only if you used my oil
> cooler and required too many links. However, it does provide a perhaps
> useful data on the BTUs you need to shed via radiator or oil cooler.
>
> Unfortunately, it uses a "Lookup" function that won't translate to
> Lotus. I have tried and check with some spreadsheet experts.
> Someone, Lotus knowledgeable would probably be able to come up with a
> substitute function, but I can't.
>
> I know you only have Lotus, I offer it for free to folks on the news
> letter who have Excel who might want to play with it. I am certain
> numerous refinements could be made to make it more "real" world, but
> like I said for first order calcuations it may be close enough.
>
> Ed My e mail is anderson_ed@bah.com
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______________________________________________________
Date: Mon, 18 Jan 1999 09:11:54 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Plan for reduction drive.
Tracy Crook wrote:
On the spring disk comeing apart in a ross re-drive I have heard
of others developeing cracks and advice was given to change
them at 1000 hrs. On my drive I have used a heavy duty truck
clutch disk but I am not sure it was really necessary. It is believed
that the Hi-Vo chain takes care of the torsional vibration thru the
dampening effect of the chain throwing out in an arc.
Lonnie
rwood@iceinternet.com
I would stick with the disk. Tracy has at least 650 hours on his
disk and maybe 900 if he did not change it when he sent the PSRU
back to Ross for overhaul at 650 Hours.
Did you change that clutch disk Tracy?
Have seen no problem with the clutch damper and still using the same one at
800+ hours. I can't imagine how the amphib driver broke one. May have
been a fluke. As far as I know, only one person has put 1000 hours on a
Ross drive so there really is no valid TBO data on this drive. Another
reason for this is that I don't think any two of them are exactly alike.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Mon, 18 Jan 1999 09:34:38 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
CC: Paul Yaw <yawpower@theriver.com>
Subject: Paul Yaw email address
StJames515@aol.com wrote:
Hi Paul,
Can you give me Paul Yaw's email address?
I tried one on his website, but got no response.
TIA
Tommy James
Paul Yaw <yawpower@theriver.com>
I have not heard from him for awhile either. He might
be out of town.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 09:18:41 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: One rotor in a KR1? Source for one rotors.
Tracy Crook wrote:
facilitator1@juno.com wrote:
Tracy, What eng for KR-1??
Original was 36hp WV. Then went to 2100cc
turbo. Like to keep it to 40/65hp.
THX, Virg
Hate to sound like I'm deserting the rotary camp here but for that plane I'd
install a 503 Rotax (52 HP) and learn the proper care & feeding of it. I
have over 730 hours on my 503 powered Twinstar. Only the piston rings have
been replaced. The 13B is way too heavy and even a one rotor would be a bit
much if they were available off the shelf (which I don't think they are).
Tracy Crook rws@altavista.net
You can get them. Try http://www.onerotor.com
Opps you will need a browser. juno.com won't work. No browser.
Here is the address and phone number.
Eco-Max Systems, Inc.
13320 Southridge Industrial Drive
Tavares, Florida 32778
Phone: (352) 742-7757
Fax: (352) 742-8308
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______________________________________________________
Date: Mon, 18 Jan 1999 09:39:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Flying list.
Anderson Ed wrote:
Add me to the list
Will send photo later
Ed
Name: Ed Anderson anderson_ed@bah.com
Local: Vienna, VA (Near Washington D.C.)
Aircraft: RV-6A
Engine: 4 port 13B naturally asperated fuel injected
First Flight: Sep 21 1998
Total hours: 16 as of 17 Jan 99
Name: Neil Kruiswyk neilk@sprint.ca
Local: Near Toronto Canada
Aircraft: Lancair 235
Engine: 4 port 13B natuarlly asperated fuel injected
First Flight: Sep 1988
Name: Jim Mosur jmosur@interlog.com
Local: Near Toronto Canada
Aircraft: Vans RV-6
Engine: 4 port 13B natuarlly asperated carburated
First Flight: July 1998
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______________________________________________________
Date: Mon, 18 Jan 1999 15:29:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Plan for reduction drive.
Gerry Hess wrote:
Hi Tracy
I was in the Ross Aero shop when your redrive was in for overhaul. The unit
looked good except for spalling on the gears which Chris determined to be
from the oil spray not correctly focused on the gears. He corrected this, as
I'm sure you know. You are correct in the use of a Sachs spring unit, part
#BBD0107UL Driven plate assembly. Your unit looked very good when I saw it.
Unfortunately, as in most experimental things (planes included) no two units
are exactly alike, as Chris tries to incorporate improvements or knowledge
gained into them. Someday it would be nice if a proven experimental design
could be sent to an engineering firm for debugging and design analysis.
There are a lot of Ross drives out there and it would be nice to know the
strengths and weaknesses and what is over or under designed.
Lou Ross was experimenting with a gearset from a Chevy Turbo 400 trans
when he took sick, and I like the gearset as the teeth are much thicker, and
the material is softer. As I'm not an engineer, my assesment is only from
experience, and I think the course teeth will stand up better to dirt, and
miss-alignment, and will heat less as there is more space at the root for
oil to be carried, instead of compressed. The softer teeth will be less
subject to spalling. The drag race crowd loves this tranny, too.
So does the off shore boat racers. Art Carr rates his PowerGlide version
at 1000 HP. It looks harder to adapt to a PSRU and may be heavier.
The planet carrier is steel rather than aluminum.
Any idea Gerry, what the ratios are with this planet set?
Art Carr does not seem to be able to tell me. Only the overall
ratio in each gear.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 15:41:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ignition Timing
Rodger Hilyard wrote:
Paul, I am running a 1974 RX-4,13B direct drive to prop at
3200 to 4000 rpm.
I would like to use the trailing plugs as a true second ignition
source, however the power output with factory timing settings
does not provide full power with trailing ignition only. The engine
responds well to trail ignition only advance, however various
sources (Racing Beat etc.) warn of engine distruction sensitivity
to trailing ign timing. Is this destruction tendency reduced/eliminated
if the over advance of trail ign. is applied only when lead ign is
inoperative??
Thanks for making this forum available. Rodger N222EX D-Fly
I don't know. I would believe Jim Mederer of Racing Beat as he
has decades of expierence with rotaries. I just saw a rotor
from an engine with a failed apex seal. It was not pretty.
The broken seal jammed in the exhaust port and tore the housing
up as well as the rotor slot.
What kind of airplane is this engine going in? I have always
wanted to try direct drive but with a turbo charger to
boost the HP back up at only 3500 RPM. One does not get much HP at
3500 RPM in a normally aspirated rotary. I think the turbo combination
has the potential to lower the BSFC or increase the MPG to put it
another way.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 15:45:32 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: One rotor in a KR1? Source for one rotors.
facilitator1@juno.com wrote:
Tracy, THX for info. being a diehard, i am going to
use 36 hp VW. Thot 1 rotor would be same wt.
Better over all. Fun etc. Virg
Say hi to Don, Beltronics, 1239 Main St
Along as you don't ask for more than 36 HP
and use a very light weight prop that VW ought to last
as long as any aircraft engine. Back in the days when I owned
a split window you could run that thing day in and day out
at its top speed of 72 MPH. :-)
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 18:14:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: End housing repair.
MAR34807@aol.com wrote:
mazdatrix also does this when they get a batch in- I recently had it done for
the rear end housing, took about a month-cost is on their web site.......
I would not be a bit surprised if they don't farm it out to Jim at RB
just across town. I have been in Mazdatrix shop and saw no such lapper.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 19:06:04 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Design
Bill Freeman wrote:
Paul,
Looking up "Chain Drives" in my Shigley "Std
Hdbk of Machine Design" (**highly recommended**,
Shigley is one of the great authors in Mech Eng).
The first point is the assumptions:
1) 20,000 hr life
2) ideal conditions of lubrication
3) no shocks or load variations
First point - no way does a prop drive qualify as
"no shocks or load variations" **especially** if you
insist on spins and acro - like some of these
big HP V8 powered birds are likely to be used.
Is your lube going to be "IDEAL"??
A few examples from the tables:
3/8" pitch chain
no: of teeth on small sprocket: 27
small sprocket RPM: 6000 (max in table)
HP per inch of face width: 16
1/2 " pitch chain
no: of teeth on small sprocket: 27
small sprocket RPM: 4000 (max in table)
HP per inch of face width: 23
5/8" pitch chain
no. teeth (small) : 27
small sprocket RPM: 3500 (max in table)
HP per inch of face: 26
So, you want a 200 hp silent chain,
and use 1/2" pitch chain; figure on
making the sprockets 8+" face width.
HEAVY and BIG.
I calculated that one of the well known chain
drives used on many AC with BIG V8 motors is
rated at about 55-65 HP by the factory method,
( I had to estimate the pitch from photos) and
the owners are claiming about 10X this HP.
I would not bet MY life that the 20,000 hr life
rating scales linearly. My guess is the life of
the 65 HP rated drive when operated at 650 HP
TO & climb plus 400 hp cruise is going to be alot
closer to 200 hrs than 2000 hrs.
Y'all be careful out there. A little bit of knowledge
is a dangerous thing. And as Paul has said:
The laws of physics will be strictly enforced.
Nobody gets a waiver :-)
Bill
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______________________________________________________
Date: Mon, 18 Jan 1999 19:02:36 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Chain specs
Wood Family wrote:
Paul,
Here are some of the specs on the Hi-Vo chain. Ultimate tensile strength
for 1" wide, 3/8 pitch is 7,500 lbs. 1.5" chain is 11,250 lbs.
There are 8 plates across the 1" chain and 12 on the 1.5", each plate .060"
There are two concentric pins per joint, they look like this when in their hole: )(
and the hole looks like a round cookie with a bite out of it. Each pin in
cross section measures .060 x .150.
Small sprocket 23 tooth and 2.754" pitch. Large 57T and 6.807" pitch.
I roughly figured that at 200 ft.lbs torque(probably high) that the chain would
have about 1275 pounds tension on it, but then I am not an engineer, nor do
I play one on TV.
Thanks for your thoughts on this.
Lonnie
rwood@iceinternet.com
200 ft pounds of torque is a tangential or tension force of 200 pounds
on a one foot radius.
If the small sprocket has a diameter of 2.754... divide by 2 or
a radius of 1.377. So 12/1.377 times 200 pounds is a tension force
of 1743. Actually that is the average torque so 500 pound is more
like the peak torque. So the peak tension in the chain is more
like 4400 pounds.
The clutch disk should moderate this peak torque somewhat. If nothing
else it should extend the chain life.
Certainly seems like it can handle it. Just keep checking the
backlash for chain wear.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 19:13:16 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Chain and Belt Drive Cantilever redux
Bill Freeman wrote:
Paul,
Probably time to reiterate the fundamental problem
with all belt or chain drive systems that cantilever
the pulley/sprocket on the end of the crank. High
bending stresses in the crank.
You've got a lot of newbys that may not have
seen that one --- and it IS important if someone
is planning to make their own redrive.
Folks, there IS a reason that most REAL reduction
drives are planetary or spur gears.
Go get 'em Paul.
Bill
Good point Bill. You are right. I forgot to mention it.
I should put this on the web site.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 19:16:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Plan for reduction drive.
Gerry Hess wrote:
Paul
I was told theTurbo 400 ratio's are 2.07 and 3.07 I have verified this by
turning the unit by hand. I have a set on my shelf that I want to play with
someday, and you are right, they are heavier right out of the box, but they
can be lightened without strength loss. The ring gear is the most massive
part and could be cut down to a wall thickness similar to a C-6. Lou Ross
did this on the ones I saw. All gears may be able to be cut narrower as
well. If the aluminum housing was heat shrunk onto the ring gear the ring
could be made thinner and still be strong due to compressive force of the
housing. In the wild state, these gears are totally self supporting and take
gobs of power.
Gerry Hess wrote:
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______________________________________________________
Date: Mon, 18 Jan 1999 19:30:30 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Planetary Gearbox Design Review
Bill Freeman wrote:
Paul,
If you can get me a detailed drwg or sketch with
key dimensions of the planetary gearset these
redrives are using, I MIGHT be able to get a guy
here in town who is the head eng for a plantary
gearbox manufacturer to to a BRIEF review of
the HP he would trust it with.
I did a carrier redesign (detailed FEA)
for him a while back and we met again the other night
at a SAE mtg where Bob Storckz (spelling?)
was the speaker.
You know Bob?
Bill
I don't think so.
You can scale this or ask me specific dimension
as I have a Ford C6 set sitting right here.
This of course is a six pinion modification
of the standard Ford four pinion set.
There are about six teeth per inch on the
roughly 4.4 inch pitch diameter ring gear.
The pitch diameter on the sun gear is roughly
1.9 inches.
Planets are roughly 1.2 inch pitch dia.
I really appreciate this Bill. It is in fact a
major breakthrough in EAA stuff if we get an
FEA on this.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 19:40:18 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ignition Timing
Tracy Crook wrote:
Rodger Hilyard wrote:
Paul, I am running a 1974 RX-4,13B direct drive to prop at
3200 to 4000 rpm.
I would like to use the trailing plugs as a true second ignition
source, however the power output with factory timing settings
does not provide full power with trailing ignition only. The engine
responds well to trail ignition only advance, however various
sources (Racing Beat etc.) warn of engine distruction sensitivity
to trailing ign timing. Is this destruction tendency reduced/eliminated
if the over advance of trail ign. is applied only when lead ign is
inoperative??
Thanks for making this forum available. Rodger N222EX D-Fly
I have been flying for the past 700 hours with advanced trailing plug timing
(same as leading plug) which gives me much better power on trailing plug
only operation. I once lost the leading coil ignition while in-flight and
did not know it until I went through the takeoff checklist the next day.
(engine died when I disabled the trailing coil)
This timing change also had the desirable effect of reducing EGTs by about
40 degrees.
So, I think I can say that at aircraft power settings & rpm the "advanced"
trailing timing is not going to cause a problem.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Mon, 18 Jan 1999 19:56:48 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: ROTARY ENGINE NEWSLETTER
Anthony Ambrosio wrote:
GOOD MORNING,
WE PLAN ON INSTALLING A ROTARY ENGINE IN OUR NEW HOMEBUILT DESIGN.
WOULD APPRECIATE ANY INFORMATION YOU COULD FORWARD. WE IN TURN
WILL SHARE DATA WITH YOU AS PROGRAM PROGRESSES.
THANK YOU.
ANTHONY P. AMBROSIO, PRES.
LEJET CORP.
NORTHFIELD,OHIO, 44067
AAMBRO@att.net
--
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______________________________________________________
Date: Mon, 18 Jan 1999 19:52:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Knock sensor location, 87-88 vs 89-91
BCGARDNER@aol.com wrote:
Paul,
You expressed a preference for the knock sensor location found on the 13B-GTR
89-91 block. Here's some correspondence from the RX-7 Turbo II listserve that
indicates some confusion about the subject. Could you elaborate why you feel
the 89-91 knock sensor location is better than the 87-88?
Thanks.
Barry Gardner
Subj: Re: Knock Sensors
Date: 01/18/1999 4:30:26 AM Central Standard Time
From: f8ldzz@lava.net (F8LDZZ)
To: Marcus_Fitzhugh@csihome.com
CC: fc3s@foci.com
On Sun, 17 Jan 1999 Marcus_Fitzhugh@csihome.com wrote:
Any ideas on why Mazda moved the [knock sensor from the GTX to the GTR]?
From the casual observer's perspective, it would seem that if the knock
sensor is in >the intermediate housing [like the 87-88], it would be more
sensitive to pinging in >the rear rotor housing because it's closer.
[Having the] Knock sensor by the spark plugs gives it a closer shot to the
combustion chamber where ignition of the fuel mixture takes place. Of course,
moving it to the front rotor housing [as it did in 1989] makes the sensor
dedicated to the front rotor only.
You also have to remember that the knock system was basically used only to
detect bad gas and low RPM knock. The massive pinging on the top end
doesn't do squat - The ECU shuts the knock sensor input off at around
4kRPM or so, due to the fact that the engines gets way too noisy to
accurately detect knock up that high.
As long as I'm playing Monday morning quarterback, it seems that
an even better approach would be to put a knock sensor on each rotor
housing and listen to both of them. Of course, adding items to the spec
sheet increases the price - and I think the price is what killed U.S. sales
of the 3rd generation.
Um, I'm a little confused on what you were trying to say? I think you
meant that the FD's [91-95] run two knock sensors? If so, not true...like the
later 89-91 models, the FD's run a single knock sensor in the front rotor
housing...
-Ted
Ted Koseki 1987 RX-7 Turbo II F8L-Speed Development
f8ldzz@lava.net 13.447@105.00mph Honolulu, Hawaii USA
f8ldzz@teamfc3s.org TEAM.FC3S - Since 1996 Founded in 1997
koseki@hawaii.edu Team Wiggle - Since 1998 "No excuses..."
For the same reason. It is closer to the source of knock.
We could do two knock sensors. In fact I think Keiths Moore's engine hadwo.
Is that right Keith? For sure both rotor housings have the boss as they are
interchangable front to rear.
I will have to have another talk with Able Ibbarra on this subject.
He is getting the most amount of power (730 HP) out of a 13B
than anybody else in the world and he is using the knock
sensors with perhaps custom detection electronics.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 23:12:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Plan for reduction drive.
Bill Freeman wrote:
Gerry Hess wrote:
SNIP
they can be lightened without strength loss. The ring gear is the most massive
part and could be cut down to a wall thickness similar to a C-6. Lou Ross
did this on the ones I saw. All gears may be able to be cut narrower as
well.
There may be ways to lighten these parts without
reducing the strength but you had better have a savvy
structural engieer do it, and preferrably with a good finite
element model. I have redesigned failed planetary carriers in
the relatively recent past and this not a job for eyeball
engineeirng ( that is why I was called in to do a detailed
FEA). My redesign has not failed once in years of extremely
heavy industrial service (cranes).
Also, do **not** make the gears narrower, this is
DIRECTLY proportional to the torque capacity. If you
reduce the tooth width by 20% you
reduce the torque capacity (HP) by 20 %.
In all probability you need to double up these gear sets (two
one one shaft, to DOUBLE the face width) to make this a
durable system. Of course, if you do, the longer shafts
will be too small a diameter unless you make a double
decker carrier, and even that may not be adequate. Needs
analysis.
Remember, these auto transmission drives are designed to
last say 100K miles at perhaps 40-60 HP in a big truck, and
MUCH less in a car, like 20 HP avg or less. How much of
that 100K is in first gear at full HP? second gear?
Top is direct, if I
am not mistaken - (I really don't know automatic trans) .
They can take
substantial short term overloads, but are not designed to
really run long term with the "rated HP" numbers you see
in the ads for these vehicles. Also, the torque converter
limits the peak shock loading, making the peak load
capacity less than if it were direct. Expect spalling of the
gear teeth due to excessive loads and low/med cycle
fatigue in the whole system. Older designs may be
overdesigned to cover up lack of knowledge and might
be more capable of surviving an overload.
This is the same problem as using auto engines in AC,
they are not designed to run at rated HP for more than
a few tens of seconds at a time - engine and tranny work together
and are designed together and have relatively little "fat" in
the designs.
Somebody needs to do a real engineering look at the
power potential for these planetary gearsets using
std engineering tools. I used to review whole gearboxes
professionally but have not done it for about 20 yrs and
am very rusty. (other than that one carrier about 4 yrs ago)
I can tell you that a 350 HP industrial planetary gearbox
from GE (100 hp electric motor, 3.5 safety factor due to
driving an impeller which could see some load variations)
about 20 to one reduction, so I think three stages, weighed
about 700 lbs and was 4 ft tall and 2ft in diam.
Bill
Thanks to Tracy Bill we have a Ford C6 based Ross gear box
that has gone 650 hours driven by a 13B in an RV6.
The Ford C6 (used with Ford's largest V8 engines) is probably
in that early over designed catagory you mentioned.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 23:31:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake porting.
Jeremy Solomon wrote:
This newsletter is a great source of information.
I purchased Bruce Turrentines videos on overhauling the Rotary and can't
recommend it enough to someone who hasn't overhauled a rotary
before. In speaking with him yesterday I got the impression that he
didn't feel there was much to be gained from intake modifications such
as porting the intakes and that more could be gained from the exhaust
end of the equation. Anyone care to comment?
I think there is a lot to be gained from intake porting. [P]
For the record i am building an 88 13B 6 port for a Cozy iv, and am
planning to use Tracy's computer and intake system.
I have also seen a few references to the "NL web site"
Do you have the full address?
Yes. Here it is just click on it.
http://home.earthlink.net/~rotaryeng/
BTW Jeremy please turn long line wrap to "ON" in your
email program.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 23:48:40 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Compact Intake Manifold
Matthew TERF wrote:
You build the hardware and give me the time and I will test it for free.
Matthew Tait (TERF Inc. off site today)
I was hopeing you would say that Matt :-)
Maybe we could build two. One with 1.5 inch tubes and one with 1.75 inch
tubes.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 23:43:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ignition Timing
Matthew TERF wrote:
Hi Tracy
Did you happen to drill out the "delay hole" in the trailing spark plug
opening to the full diameter to match the leading plug in this
configuration. Or did you leave it to the original smaller (~1/8") or so
opening. Did you ever do an experiment where you ran with only the Leading
plugs / only the "trailing plugs" running in leading timing and all 4 to see
what the difference in fuel economy, performance and EGT's resulted... Just
curious.
Thanks so much Matthew Tait of TERF
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______________________________________________________
Date: Mon, 18 Jan 1999 23:14:33 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ignition Timing
Gary C. Buster LPT wrote:
Tracy... was the decrease in EGT due to an incomplete burning of the
mixture??? What happens to the fuel burn efficiency?? What did you set the
(both) timing at for the lead?? (did you slightly retard the lead at all??)
Wow, bud ... this is powerful stuff here!!
Gary C. Buster LPT
gbuster@ballistic.com
Tyler, Texas 12a bridgeported Ross PSRU 4 blade Warp drive tandem
gyroplane N69EF (450+ hours)
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______________________________________________________
Date: Tue, 19 Jan 1999 05:53:22 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ignition Timing
Anderson Ed wrote:
Paul,
I am fairly certain that Tracy Crooks' ignition computer takes care of
the problem of making near full power with the trailing plug. I believe
the trailing plug normally fires approx 15 degrees after the leading
plug. However, Tracy has his ignition computer programmed such that the
trailing plug fires within a few microseconds of the lead plug.
When I disable the leading igntion module using the "Mag" check feature
of Tracy's ignition, the rpm does not drop althought there is a slightly
different sound to the engine and EGT goes up slightly.
check with Tracy
Ed Anderson
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______________________________________________________
Date: Tue, 19 Jan 1999 07:46:38 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Did a rod break?
This kind of stuff does not happen with rotary engines.
This is one of the reasons that I think rotary engines
will someday be the engine of choice for airplanes.
Paul
" The engine with the propeller still attached was lying inverted in the
middle of the
debris. An examination of the engine revealed a 5 inch hole on the top
of the casing directly above the #3 and #4 connecting rods.
After removal of the oil sump and melted ash, an additional hole was
found on the bottom of the casing. The bottom hole aligned
with the #4 and #5 connecting rods. The majority of the #4 connecting
rod was absent, and the #5 connecting rod was protruding
through the casing. Both rods displayed elongation and discoloration
similar to that found in heat distress. The engine was shipped
to a tear down facility for further examination."
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______________________________________________________
Date: Tue, 19 Jan 1999 10:32:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Did a rod break?
Anderson Ed wrote:
Paul, was this related to Steve Parkmans accident or did I miss an e
mail
Ed
No. It was just a random fatal accident I picked out of this
months NTSB report. Nothing to do with homebuilding.
It could have been a massive oil leak or started with a
hole in the piston top pumping all the oil over board
or any number of things piston engines are subject too.
About the only way you can have this happen in a rotary
is run it without oil. The rotor, compared to
a piston, is cannon proof and of course there are no
rods to break.
Paul
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______________________________________________________
Date: Tue, 19 Jan 1999 10:39:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ignition Timing
Tracy Crook wrote:
Gary C. Buster LPT wrote:
Tracy... was the decrease in EGT due to an incomplete burning of the
mixture??? What happens to the fuel burn efficiency??
What did you set the (both) timing at for the lead?? (did you slightly retard
the lead at all??)
Wow, bud ... this is powerful stuff here!!
Gary C. Buster LPT
gbuster@ballistic.com
Tyler, Texas 12a bridgeported Ross PSRU 4 blade Warp drive tandem
gyroplane N69EF (450+ hours)
I think the decrease was due to MORE complete combustion. The reason rotary
EGTs are higher than most recips is incomplete combustion of the "end
gases". I don't pitch it as an advantage but there was an increase in
power with the advanced trailing timing. (< 1%) This result was verified
by Everett Hatch on a dyno who also deserves credit for steering me in that
direction. Mazda's timing choice was done for a reason - EPA
requirements. The full explanation is too long for this message.
Tracy Crook rws@altavista.net
BTW Gary what was the date of your first flight?
I want to add you to our flying list.
Paul
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______________________________________________________
Date: Tue, 19 Jan 1999 10:56:33 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ignition Timing
Tracy Crook wrote:
Hi Tracy
Did you happen to drill out the "delay hole" in the trailing spark plug
opening to the full diameter to match the leading plug in this
configuration. Or did you leave it to the original smaller (~1/8") or so
opening. Did you ever do an experiment where you ran with only the Leading
plugs / only the "trailing plugs" running in leading timing and all 4 to
see what the difference in fuel economy, performance and EGT's resulted...
Just curious.
Thanks so much Matthew Tait of TERF
I did not change the trailing plug hole at all. This is not recommended
because the pressure differential between chambers is at near maximum as the
apex seal crosses the trailing plug hole. That's why its so small in the
first place.
Take another look at my Fires of Hell ignition system on the web site
for a way of making a surface gap spark plug flush with the throchoid
housing surface. Should work well with a platinum center electrode.
Mazda also found (in the Le Mans engines) that three spark plugs
are better than two. Torque (& HP) was up over 3% and BSFC
was down almost 4% at 6000 RPM. Mazda felt if it were not
for the small hole required it would be even better. [P]
I do a trailing and leading plug only test during every pre-flight engine
check. (The EC1 has a switch to disable them one at a time).
There is a small power and fuel economy penalty when running on trailing
only but its quite small. Almost no difference at all when on the leading
plugs only. The 60 minute flight I made with trailing only (when the
leading coil went out) is the only extended test I have made. I knew when
the coil went out by the increase in EGT although I didn't know the reason
at the time.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Tue, 19 Jan 1999 12:26:37 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Did a rod break?
Anderson Ed wrote:
Ok thanks, Paul
I agree, that is one of the primary reasons I chose the rotor motor
which was its mechanical simplicity and therefore greater inherent
reliability than a reciprocating engine. I mean NOT ONE thrown rotor to
date {:>}.
Ed
Paul ROFL
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______________________________________________________
Date: Tue, 19 Jan 1999 12:51:33 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Chain drive sizing
Lonnie Wood wrote:
To Bill Freeman,
I looked up the horsepower ratings on both the Hy-Vo chain and
also the Silent chain in the Morse catalog, both in 3/8" pitch.
The Hy-Vo with 23T small sprocket @6600 rpm is 100 hp per inch.
The Silent chain with 23T sprocket @6600 rpm is 43 hp per inch.
These chains look almost identical but are not the same animal.
This is with spray oiling, wich I have incorporated.
The catalog did not give hours of service.
Are these figures overly optimistic or are they conservative as some say?
Also I have incorporated a bearing on both sides of the small pulley.
Paul,
I agree with your numbers on chain tension. The 1275 lbs. I had
come up with was from the published torque of 138 ft lbs @3500 rpm.
What kind of ball park torque could be expected at 6500 rpm?
Lonnie
rwood@iceinternet.com
Since HP = Torque X RPM / 5252
Torque = HP X 5252 / RPM
There apppears to be lot of differing opinions on the required
chain size. The Manufacturers say one thing and the Mechanical
Engineering hand books say another. Your chain looks like it might
last at least for awhile. I do not think it will break right
away. I would check the back lash on a regular basis by grabing
the prop and swinging it back and fourth. Keep a log of the back
lash. If it starts to increase rapidly take the box apart and
check the chain and sprockets for wear. You will have to replace
both the chain and the sprockets. Do the check when the box is at
room temp. To be precise you should also record the temperature.
In any event a chain PSRU is going to be a lot heavier than
a planetary. There is no beating a planetary for reduction
efficiency in terms of weight. A centry of AC engine expierence
proved that over and over again. All late model radial piston
engines used planetary reduction drives.
Spur gear and chain boxes have a problem in common. When the box heats
up the distance between the sprockets or gears increases. In the
case of the chain this is not so bad. In the case of the spur gears
the gears come out of optimum mesh slightly. The chain must have
initial slack to allow for this.
Paul
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______________________________________________________
Date: Tue, 19 Jan 1999 12:24:05 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Year Models 13B
JPerdue347@aol.com wrote:
Is there a best year model to pick when searching for a 13B to rebuild?
This in regard to using Tracy Cooks EFI.
To simplify.... get the latest engine you can afford.
Also, are there any AC flying a TERF engine?
None are flying but none have fallen out of the sky either :-)
This is a joke Matt Tait of Terf likes to use :-)
John Perdue
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______________________________________________________
Date: Tue, 19 Jan 1999 14:55:29 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Year Models 13B
Tracy Crook wrote:
JPerdue347@aol.com wrote:
Is there a best year model to pick when searching for a 13B to rebuild?
This in regard to using Tracy Cooks EFI.
To simplify.... get the latest engine you can afford.
True, but it should be 1986 or later to get many of the improvements Mazda
incorporated (like the 12 pin rotor gears etc).
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Tue, 19 Jan 1999 14:58:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A better way of lubing tip seals?
Anderson Ed wrote:
Hi Jeff
Glad to see you back - just stand far away {:>}. By the way, I didremove the foam filter and now have 28" manifold pressure at sea level.
Looks like I gained 2-3 inches with the foam removed. However, did not
seem to get the power gain that I had expected. I suspect that could be
because I need to increase the fuel injector timing for the high end.
In fact, I seem to have slightly less power on this 50F day vice the
power I had on the 15F day I previously flew. I know the denser air
would contribute to some power gain on the colder day. However, if I
now flow more air, with an air density EFI and have not changed the
injector timing, I would presume that could account for not developing
quite as much power. More air + same fuel=leaner mixture=less power???
Ed
Ed Anderson
RV-6A 13B powered
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______________________________________________________
Date: Tue, 19 Jan 1999 20:11:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Did a rod break?
Carl Stevens wrote:
On Tue, 19 Jan 1999, Paul wrote:
Anderson Ed wrote:
I agree, that is one of the primary reasons I chose the rotor motor
which was its mechanical simplicity and therefore greater inherent
reliability than a reciprocating engine. I mean NOT ONE thrown rotor to
date {:>}.
Is there a catastrophic failure mode for rotaries? I have not heard
of any but am curious. I can picture catastrophic failures due to
failure of an exhaust system, or a blown turbo, but how about
the motor itself?
Carl
This came up quite some time ago on here. If you over rev it
(not possible with a prop load on it) the phaseing gear could fail
and cause the eccentric shaft to punch the rotor tip through the rotor
housing. Its a very rare failure mode however.
If an apex seal
fractures and a peice of it gets loose in theory it could
jam the rotor against the exhaust port however what usually
happens in a case like that is the rotor housing and rotor
is badly damaged without the engine stopping.
If Mazda ever releases the side exhaust port engine this failure
mode should be eliminated.
We are in debit to Finn Lassen for demonstrating what happens
to a rotary when you run it at 10,000 RPM without oil.
It keeps running until you shut it off. At that point the
eccentric shaft solders itself to the main bearing shells.
Once you fix that, replace the bearing shells and clean up
the shaft the engine will, and neigh does, run again.
None other, that I have heard of.
Paul
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______________________________________________________
Date: Tue, 19 Jan 1999 20:24:47 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Air filters and manifold pressure.
Jeff Spitzer wrote:
Anderson Ed wrote:
Hi Jeff
Glad to see you back - just stand far away {:>}. By the way, I didremove the foam filter and now have 28" manifold pressure at sea level.
Looks like I gained 2-3 inches with the foam removed. However, I did not
seem to get the power gain that I had expected. I suspect that could be
because I need to increase the fuel injector timing for the high end.
In fact, I seem to have slightly less power on this 50F day verses the
power I had on the 15F day I previously flew. I know the denser air
would contribute to some power gain on the colder day. However, if I
now flow more air, with an air density EFI and have not changed the
injector timing, I would presume that could account for not developing
quite as much power. More air + same fuel=leaner mixture=less power???
Ed
Yes and no. While a significantly leaner mixture would give slightly less
power, I doubt you picked up 2-3" of manifold pressure without a gain in
power. More likely is that your prop can't make use of the power. I guess
I need more info about how you think you didn't gain power. Also I'm
confused when you say "injector timing". Do you mean injector pulse width
and whose EFI are you using? More questions than answers.
Jeff Spitzer
You are not using an Ivo prop are you Ed?
Do you have an EGT gauge? If so what was it reading both days?
Paul
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______________________________________________________
Date: Tue, 19 Jan 1999 20:35:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Year Models 13B suitable for AC use.
David Munday wrote:
So when are the year breaks for turbo engines? I'd love to see a
table of years and changes with notes pertinent to aero conversion. I
bet it'd help a lot of other folks considering Mazda engines too. I
keep planning to go through Tracy's book and construct such a table,
but there're a lot of things I keep planning to do.
--
David Munday - mundayde@muohio.noise.edu
My email address is not noisy.
Webpage: http://www.nku.edu/~munday
PP-ASEL - Tandem Flybaby Builder - EAA-284 (Waynesville, OH)
"Specialization is for insects" - R. A. Heinlein
We would love to have you do it too Dave :-)
They are all great engines when you mix the 2 cyc oil with the fuel
and make a few minor changes.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 00:51:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Design
Bill Freeman wrote:
Paul,
I am not an expert on chain drives, just looking in the
handbook. I would not doubt the Morse catalog, it is
certainly more credible than an engineering handbook
since the tables are for their product, which they should
know well.
It is interesting to go into my tables for silent chains and
find the closest entry - 23 tooth small sprocket, 6000 RPM
and 3/8 in pitch chain. My table says 12 hp per inch of face.
Lonnie's says 43 hp, about 3.6 X - a lot more!
Also, they have a service factor table that says an internal
combustion driver driving a "smooth" driven load condition
needs a 1.4X design factor.
In any case, I would certainly defer to the manufacturer's
catalog as long as their design recommendations are being
followed in full.
Is there any estimated chain life assumed for those tables?
Mine assume an industrial type 20,000 hrs (about 2 1/4 yrs
of continuous service) .
Bill
--
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______________________________________________________
Date: Wed, 20 Jan 1999 00:48:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: New Mazda Rotary
Archie Frangoudis wrote:
Last year I read several articles on the new 1999-2000 Mazda rotary. I
believe it was rated at 235 HP.
Sent a copy to Mr. Yaw, but have not read or heard anything about actual
production.
Anybody have anything on this?
Archie
From this web site. So far it is only avaialable in Japan.
http://www.e.mazda.co.jp/Publicity/Public/9812/981215be.html
Here is part of the press release.
December 15, 1998
The New Mazda RX-7 Powered by 280 PS Rotary Engine
- a pure sports car improved its "Fun to Drive" -
Mazda Motor Corporation today announced the long-awaited arrival of
the new RX-7. Mazda's modern version of a pure sports car will be
available beginning January 21 next year through Mazda Anfini dealers
throughout Japan.
The RX-7 has a legendary tradition for offering driving enthusiasts
the greatest "fun to drive" character. Building on that reputation, the
new RX-7 turns heads with its powerful, unique exterior, and Mazda's
compact, lightweight, and high-powered rotary engine.
The main features of the new RX-7 are:
1) Enhanced turbocharger efficiency and cooling performance that
afford increased maximum engine power of 280PS (JIS net) for both the
Type RS and Type R. models
-Higher engine power and the new RX-7's light weight achieve a
power-to-weight ratio of 4.57 kg/PS for the Type RS model.
Despite the enhanced driving performance and new equipment, the price
for the 280 PS top-of the line models barely increases. The 5-speed
manual transmission, type RB, with a maximum 265PS engine output costs
2,898,000 yen (one price nationwide), making the new RX-7 more
affordable than ever.
The monthly sales target is 500 units.
Highlights
1. IMPROVED DRIVING PERFORMANCE
Enhanced turbocharger efficiency and cooling performance due to
increased air-intake allows the new RX-7 to achieve a maximum output of
280 PS/6,500 rpm (Type RS, Type R) increased engine power combined with
the light weight of the type R model realizes a power-to-weight ratio of
4.5 kg/PS.
Along with greater output at high engine speeds and an extended top
end, the torque at medium engine speeds has been increased for better
acceleration. Specific changes that have improved engine performance
include:
* The use of abradable seals and increased air flow provided by an
ultra-high-flow turbine achieves a turbocharger pressure approximately
1.2 times previous models.
* Modifications to the internal structure of the main silencer have
reduced exhaust pressure, contributing to lower resistance.
* In addition to increasing the aperture surface area of the
air-intake, including the radiator and intercooler.
* The air cleaner uses a separate air duct that allows air to pass
over the vehicle for more efficient cooling.
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______________________________________________________
Date: Wed, 20 Jan 1999 08:34:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Andersons performance.
Anderson Ed wrote:
I have a wood fix pitch propeller 68"dia and 72" pitch (non-adjustable
{:>}. I suspect you may be correct, Jeff, that I may have more pitchthan I can use. The prop is in the test stage, after I get sufficient
data on rpm, airspeed, rate of climb, I send the prop back for "fine
tuning". Tracy's orginal prop was from the same manufacture and he had his
pitch reduced, but told me that he later wished he had not as he got
more power out of his engine he could have used the increased pitch.
I don't think pitch is problem Ed or you would have a real tough
time getting off the ground and climbing. Roughly what is
your takeoff roll? Your climb rate? Are you using a GPS for your
speed runs in both directions? Your airspeed instrument
could be out of calibration. Your prop looks right.
So, before I have my prop fine tuned I want to make certain I have the
engine giving me all the horsepower it can. The prop limits me to 5000
rpm at sea level the static thrust rpm. This gives me a prop rpm of
2.17:1 (Ross Areo PSRU) = 2300 rpm. The prop manufacture indicated that
with that prop and that prop rpm it indicated that the engine should
give apprx 165HP at WOT. I do not appear to be getting quite that much
power based on the aircraft performance, but closer to 150 HP.
Of course with a prop with less pitch, I could probably turn more rpm
thereby gaining an increase in HP which would increase airspeed, etc.
The problem is I am unable to tune the EFI for the 5000 plus rpm range
on the ground as the prop load precludes the engine from turning faster
that 5000 on the ground. In the air I can get 5800-6000 rpm, but trying
to fly, tune the EFI with a laptop for the higher RPM possible in the
air and try to note the effects of any injector timing changes is just -
well, lets same imprecise at the best.
All those RPMs sound about right to me. Perhaps a wee bit low.
I suspect you may have some sort of drag problem.
Perhaps cooling drag. Are you using the stock RV6 cooling
openings in the cowl? Perhaps those large mufflers.
Have you checked the accuracy of your tach?
I am considering buying and hooking up a fast response AF meter to assit
me setting the injector timing more accurately.
I am getting between 1200-1500degrees F on the EGT. At 5800-6000 rpm it
gets close to 1600F but no higher. The EGT temp sensors are approx 8"
from the exhaust port one each in the two 2" dia exhaust headers.
The pipes seem a wee bit large in dia and perhaps effectively
too long. Take the mufflers off,
if you can, and sneak out at 80 to 90% power for a test flight.
Yes, by injector timing, I am referring to injection Pulse width. I
have a HALTECH, Air density-based after-market EFI. You adjust the
injector timing for 7 rpm ranges (1000 rpm spread each) and 64 manifold
pressure bins (32 if non-turbo)within each range. Basically, you are
apparently building a fuel MAP using graphical bars (using a laptop) to
adjust the timing for each pressure bin in each RPM range. Then using
the manifold pressure readings, throttle position, and rpm the EFI
apparently looks up the injector timing for those engine parameter
values. So if the injector timing is not manually set on the money for
each parameter bin, you could have over rich, over lean or right on
depending on what injector timing you selected for those engine
parameters.
I have a weber throttle body with two 50mm throats each containing two
34 lb/hr fuel injectors. I have air hornes on each throat to smooth the
airflow into the throttle body. Fuel pressure runs 38-40 psi.
What is the intake pipe length and diameter Ed. Everett told me certain
intake pipe lengths were death on power. The picture of your intake on
your web site does not complete so I can not see it. Also I see no
cold air intake duct. What is that box on the bottom of the engine
I see where the intake manifold normally resides?
Another remote possibility is your lack of a dropped oil sump is keeping
too much oil up inside the engine and sapping power. How many quarts
are you running in it now?
Now, another factor is my oil temp does climb to around 220F at
sustained high power settings, but the coolant temp stays below 200F. I
am told that over heating rotaries will tend to lose compression/power
if too hot. But, did not think 10-14F would make that much difference.
In any case, the engine does not give any indication of damage from
overheating as best I can tell. It starts easily, no smoke on start up
or while running. I accelerates readily from 5000 - 5800/6000 rpm in the
air and on a cold day I can get around 6100 rpm in the air. I would
like to get 6250 or better 6500 and I believe that would give me a solid
160-165 HP which would be fine.
Just for the heck of it Ed what is the compression on your engine
when you crank it at 250 RPM? Should be around 85 PSI.
So thats about all the info I can think of that might be pertinet. I
would have loved to have put the engine on a dyno for testing and tuning
the fuel injectors, but no available facility anywhere near me that I am
aware of.
Ed Anderson
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______________________________________________________
Date: Wed, 20 Jan 1999 08:56:37 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Design
Lonnie Wood wrote:
I could not find in the Morse catalog anything about chain life.
Interesting tidbit: The Hy-Vo Chain was invented and patented
by Morse in 1965 for some 4 wheel drive vehicles and front wheel
drives and transmissions.
Lonnie
rwood@iceinternet.com
I looked in the tenth (1996) & latest edition of Marks SHFME and
it confirms what Bill said about HP per inch.
Type III chain, 3/8 pitch, 25 teeth, 6000 RPM, 14 HP per inch
no shock load.
It is remarkable what Morse is claiming.
It would be interesting to call them and ask them about
the difference.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 10:07:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance
Anderson Ed wrote:
1. Pitch/Climb Rate
Have not measured takeoff roll, but it gets up to speed and airborne
quicker than a Cessna or Piper, in less than 1000 ft. My measured rate
of climb at 3000 ft is 1400 fpm tapering off to 1000 fpm at 6000
altitude. Not the top of the line for an RV, but not terribly bad. I
believe that Tracy was getting around 4800-5000 static thrust rpm
initially, but that was early on. I know Tracy is doing better now with
his EFI, but last I knew he had the composite propeller and while it
apparently greatly improved the low speed acceleration, it hindered the
top speed due to the shape of the blades near the root.
So would ask him his static RPM, but with the different prop, probably
would not be a valid comparison.
He is not running the IVO composite now. He is back to the wood prop.
I saw it at Christmas time.
Yes, I did calibrate the airspeed indicator with GPS and it within 1 mph
at 160 IAS and about 2 mph off at 120 IAS and I am told that is very
close. At 160 IAS at 8000 feet I get 171 MPH TAS so its not like I'm
exactly poking along. But a 150 hp engine at my gross flying weight I
should get in the high 180s or low 190s TAS airspeed wise. So I am
about 10-20 mph slower than the design spects indicate I should be for a
150 hp RV even at my higher weight. So either I am not producing the
power I think I should, the prop is over pitched restricting rpm/hp, or
I have a heck of a lot more drag for some reason.
2. Regarding Drag
I am a little on the heavy side for an RV-6A, about 120 lbs heavy and
the boxy wings do have a fairly steep drag curve if not on Step, could
be some loss there. I use standard RV-6 cowl openings for the
radiators. The exhaust are 3 1/4" in diam and are behind the lower cowl
exhaust opening so would be surprised if they offer much additional
airflow resistance, but could be a mph or two loss there.
My Tach appears to be on the money, checked it with a propeller rpm
instrument.
It is not so much a question of back pressure as it is of tuning.
3. Exhaust pipes
I can take the exhaust pipes off without too much trouble and may do
that later. The length of the headers from exhaust port to muffler is 17
inches. The 2" dia is on the larger size, just figured based on the
adverse impact of exhaust back-pressure on a rotary, that 2" dia pipe
each own straight thru muffler will present min back pressure.
4. Intake Manifold length.
The "box" intake manifold is one brewed up because with the upper weber
intake manifold and stock lower manifold interferred with motor mount.
So I had air intake runners machined in two slabs of 1 1/2 inch aluminum
and bolted the two slabs together. tried to keep the same dia runners
as the stock. The total length of intake manifold from base of throttle
body to intake port is approx 13-15 inches.
As I recall Everett said 12 inches is the length to avoid. You might
be heating that intake manifold too much as well.
Sounds like the radius of the bends are too sharp as well.
Individual pipes would conduct less heat from the block.
I would build a new intake manifold as soon as possible with
much longer pipes and larger radius bends. From the looks
of the pictures I think you could wiggle them around
the motor mount tubes. It looks like you could go straight
down out of the ports for aways before doing a 180 and
back stright up.
Is it a six port engine?
Have not yet run a compression check, so sounds like that is easy enough
to do. Do I leave the plugs in the other rotor housing when cranking
for compression or take them to reduce the cranking load. Or does it
matter as long as I get 250 rpm cranking? I do use a ram cold air duct
for providing air to the throttle body.
Leave all the plugs in except the one you are checking unless the
starter won't get the RPM's up to 250.
5. Oil Pan,
I put 5 quarts in the system, which gives me approx 3 inches up block.
However, 3" does not look like it would get high enough for the rotors
to be effected their opening to dump oil to the central housing appears
to be higher up from the side of the block.
In short, there is enough power to fly safely, just believe I should be
getting 10-20 mph more if I were producing a true 160 hp. I do have
wing, gear, and tail fairings as well as wheel pants on.
A lot of guys flying the RV now have the laminar flow wheel pants
and the sheared wing tips which are worth probably near 10 MPH.
Tracy has the wheel pants but not the tips. Course his is
a tail dragger which is worth some.
I don't want to give the impression that I am disappointed in the rotor
motor. I know that it is capable of giving me 160+hp at 6000 rpm, so it
is something in my design - and it well may be the intake system.
I will do the pressure check just to make certain. Jay out of Tucson
did the overhaul and I believe the porting and it has 56 hours total
time on it. No indication of any problem, but I guess the pressure
check should clarify that aspect.
So, thanks for the comments and suggestions, keep them flowing as they
have help me work out the other bugs and I am certain I will find that
additional 10-15 hp I think I am missing.
Ed Anderson
The most likely thing that I can up with so far Ed is the intake
manifold. Mazda goes to the weight and expense of tuning the intake
even on the turbo motors. Abel Ibbara is getting 730 HP out of
the stock tuned intake manifold with just some minor increase in the
pipe diameter due to extrude honeing it.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 10:30:36 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold.
Ed here a trick you might want to try.
Get some blue styrofoam and carve intake manifold tubes out of it.
Wrap it with cellophane(s) tape as a parting agent and wrap epoxy
saturated fiberglas tape one or two layers around the
styrofoam tubes.
Use acidtone (s) to eat out the foam after it cures
Check the tubes for pin hole leaks. Make a header out
of a 1/4 inch aluminum plate and short peices of aluminum pipe.
Connect to the composite intake manifold tubes
with hoses and hose clamps.
Viola you have a light weight complex intake manifold that
won't pick up a lot of heat.
Plastic intake manifolds are used in the new Chevy LS-1 v8
engine found in the Corvette for this reason.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 10:33:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Andersons performance.
Tracy Crook wrote:
A few obsevations here based on what I've seen Ed.
First, 35 degrees increase is a big change in ambient temperature. It will
affect results. I think there is still optomizing to do on your cooling
system. During a flight last week when takoff air temp was 45 degrees, I
had to stuff a rag in one cooling inlet which cut my radiator area in half
and still could not get coolant temps above 180 degrees. The oil temp would
not go over 165 degrees which is too low. Note that the oil cooler (Mazda)
has a built in thermostat that bypasses it when oil temp falls below 158
degrees. In cruise, the bypass was on all the time (oil temp was 148)
Your thoughts on power Vs mixture could have some merit. The rotary has an
enormous (compared to recip) running range for mixtures. I can't claim to
know all the reasons why. Just as an example, at takeoff with WOT, 5150
rpm, max power mixture, the engine will suck down about 15 gph. If I lean
it out I can reduce fuel burn to 10 gph but of course the power is down
significantly (but engine is still running smooth, no missing, etc) Ed,
does that EFI have a manual mixture control? I now think this is a MUST
HAVE on an aircraft EFI. The reason why is a long subject that I'll cover
another time. One clue that you might be lean at full power is that my EGT
at max power is about 1750 degrees, well above what you see. It cools off
at leaner settings. Your comments also reinforce my feelings that an
on-board EFI programmer that is simple to operate is a "gotta-have" for an
aircraft installation. Fancy bar-graph and duty-cycle readouts look really
cool but does it really matter whether you know that your injectors are
running at 42.5 % duty cycle at 24 inches Manifold pressure? Sorry,
couldn't resist the urge to pontificate on my EFI design :-)
Also note that it is hard to judge power increases by observing top speed or
rpm change (with propeller load). This is especially true with the
Performance Prop we both use. This is a so-called "almost constant speed"
prop and it really does work. The difference between static and top speed
rpm is about HALF what the IVO prop gave me. A relatively large increase in
power will only increase rpm by a surprisingly small amount (with the
Performance prop) The best indicator (without a good dyno) of engine power
increase is by measuring rate of climb. This has to be done under the same
test conditions (air temp, gross weight, etc) to give valid results.
Keep plugging away at it Ed. You're already ahead of where I was this early
in the development stage.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Wed, 20 Jan 1999 10:35:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Coatings on late model (89+?) engines?
MAR34807@aol.com wrote:
I am rebuilding an 89 engine-and it has a "soft" type coating (teflon?)
between the rotor side seals and the edge of the rotor. My 94 shop manual also
shows this coating. There is no idication of what it is for or made of. Anti-
friction? Any ideas out there? Just curious. The faces of the 89 rotors are
not coated.
In a word... smog. Cuts down on the unburned hydrocarbons hideing in
there.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 10:37:54 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Design
Tracy Crook wrote:
Paul wrote:
I looked in the tenth (1996) & latest edition of Marks SHFME and
it confirms what Bill said about HP per inch.
Type III chain, 3/8 pitch, 25 teeth, 6000 RPM, 14 HP per inch
no shock load.
It is remarkable what Morse is claiming.
It would be interesting to call them and ask them about
the difference.
Paul
Those numbers (in the book) have got to be conservative. My Yamaha XS-11
motorcycle (98 HP) uses a Hy-Vo chain as the primary drive from crank to
clutch and is only about 1.3 inches wide. It has over 65K miles on it and
I've never heard of one breaking in spite of the abuse typically given to
motorcycles of this type.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Wed, 20 Jan 1999 13:36:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance]
Anderson Ed wrote:
Ok thanks Paul,
I would not be surprised to find that getting rid of that manifold
would improve performance. You are right, there are some very tight
turns just before it goes into the ports - like the roof of the intake
tunnel is only 1" below the block, so when the air turns to go into the
port is making a short radius 90 deg turn - air probably has a standing
wave just before the port. I have a manifold design that another gent
sent me that sounds very much like what you suggested. I was toying
with the idea of a carbon fiber/kelvar composite manifold, but was not
comfortable with doing hi temp composite work on such a critical items
as the intake manifold. I will get right on the new intake manifold.
Throwing away that boat anchor of a manifold would also save me 10-15
lbs and you are correct that slab heats up to about the same temp as the
block.
Yes, it is the 6 port 13B. However, the torque tube airflow tubes have
been removed as I did not feel I need much low RPM torque.
So once again thanks for your time and advice.
Ed Anderson
Wow! I thought it might be heavy but I did not guess it would be
that heavy. 0.040 wall, 1.5 inch dia. aluminum tubing 31 inches long
weighs about 0.6 pounds each. So six would weigh only
about 3.5 pounds or so. You could combine the outer dual
ports in one 1.75 inch dia. tube. With some saving in welding
and weight.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 13:57:30 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Year Models 13B suitable for AC use.
David Munday wrote:
When (if) I get around to it I'll certainly share. What I was hinting
at was that someone else might have done it already or may do it
before I get around to it sometime in the next millennium. If they
have or do, I hope they'll share as well.
--
David Munday - mundayde@muohio.noise.edu
My email address is not noisy.
Webpage: http://www.nku.edu/~munday
PP-ASEL - Tandem Flybaby Builder - EAA-284 (Waynesville, OH)
"Specialization is for insects" - R. A. Heinlein
Did you see the link on our NL web site on the subject Dave?
Keep checking the web site we are always updating it.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 13:53:11 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Andersons performance.
Anderson Ed wrote:
Tracy, as always, thanks for your insight and info.
I agree about the need for cooling optimization. The radiators appear
to have excess cooling capacity, but the oil temp even with the new 5"
duct still climbed to 220F at sustained power of 6000 rpm on a 40F day.
I am beginning to wonder whether the oil cooler (an Earl's Performance
model) is up to shedding the heat althought the BTU/Air velocity graph
indicates it should. I do have a stock Mazda oil cooler in the work
shop, so guess I should just bite the bullet and install it as yours
appears to be more than adequate.
You may well be correct about the air/fuel ratio. I do have a rich/lean
mixture control (+-10%), but since I can't get 6000 rpm on the ground
don't know whether I have guesstimated the correct injector timing for
6000 rpm. It may be too far off for the limit range of my mixture
control to correct.
If I am running too lean that could account for both the low EGT and
power. Climb looks like 1400 fpm at 3000 ft weighting 1590 lbs at 120
IAS, getting 171 TAS at 8000 MSL.
As you pointed out, trying to fly an RV with one hand, work the laptop
with the other with only one eyeball working is NOT idea. Your design
clearly demonstrates the value and importance of knowing and taking the
Operational environment into consideration in the design process.
I did not realize that the performance Prop was of the almost constant
speed design, although now that you mention it the blades are a little
thinner than on some of the other wooden props I have seen.
Also, thanks for the words of encouragement. I am only where I am at
due to the work you have done earlier. You blazed the trail and even if
there are still a few vines and brush still hanging over it, it much
easier (and safer) to follow quickly once the first cut of the trail is
made.
I am not discouraged, just getting a little frustrated redoing the oil
cooler system. But the bugs are falling one by one{:>}.
By the way, I have one of your earliest conversion manuals, so wanted to
know whether your latest one has more data and possible I should get a
more up-to-date version. Also, if you can find the time, I would
appreciate getting a copy of the terminal pin-out notation for your
combined EFI/Ignition module. The only reason, I have not purchased one
- is I did not know how much I may have to change my wiring to
accommodate it. The HALTECH is not bad, but I really don't like having
to take up payload with a laptop. Besides, asking my spouse to hold the
lap top while I diddle with it on a flight is an image that is better
left unrealized{:>}
Say Hello to Laura for me. How was Christmas in the new house (or is
this the second Christmas in it)?
Ed Anderson
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______________________________________________________
Date: Wed, 20 Jan 1999 13:49:22 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold.
Anderson Ed wrote:
Sounds worth the effort. At least I can do that with having to get
pipes bent and taking it all to a welder. I presume expoxy rather than
polyester or Vinyal resines??
Thanks
Ed
Oh yea it has to be epoxy as polyester will disolve styrofoam.
Try a small sample first. Also check and make sure acitone(s)
desolves the foam because the last time I tried this trick
was in 1967 when I was working for Chaparral Racing. We used
to make brake cooling ducts with this trick.
BTW the epoxy will take the heat as Klaus's O-200 oil sump
is made with epoxy and carbon fiber.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 13:59:47 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold.
Anderson Ed wrote:
I don't know what 6061 weights per cubic, but its a total of 2.85 inches
thick and approx 11" long and 7 inches wide. So the tubes have got to
weigh a LOT less.
Ed
Most aluminum is around 0.1 pounds per cubic inch.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 15:33:10 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold.
Anderson Ed wrote:
Then that boat anchor weights approx 21 lbs minus that material taken
out for the runners, still probably >18 lbs. Soooo perhaps that is were
my performance went{:>}. Clearly its got to go for a number of reasonsincluding airflow, weight, aesthetics, etc.
Thanks Paul
Ed
Its been years since I heard the term "standing wave".
I guess we need a slotted line so we can check the VSWR on that
manifold :-)
I use to work for Melpar back in the late 50's early 60's.
I think Scientific Atlanta bought them out.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 15:39:14 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Hurley tip seals
Jeff Spitzer wrote:
I went to the Hurley engineering website to view the innovations there. I
humbly submit the following opinions:
On the swing tip seal: I think this is one of those ignorance vs. genius
things. One of us is ignorant. I don't see what this is "fixing". Maybe
if it was explained to me it would show that I am the ignorant one. There
are a couple known problems with conventional tip seals. 1) They don't
seal too well in the corners. This rocking deal would have to be one piece
whch is the worst solution for this problem. 2) They run too hot. This is
caused by high velocity exhaust flowing over the seal while the exhaust
port opens. The rocking seal would have a teriible time with this as the
thin "wing" would not be able to conduct the heat to the rotor and would
probably burn. I could go on about how I don't see how it exceeds or even
meets conventional seal performance in many other subtlties but I revert to
my original statement.
On the direct oil injection to the tip seals: The reason for the excessive
tip seal wear on the groove is because of excessive temperature primarily.
The oil is broken down in the groove. I highly doubt that they plan to
inject enough oil into the groove to fix the problem. If they inject
substantially more but not enough the result will be a stuck seal rather
than a worn one. There is a delicate balance between burning off the oil
and lubricating with it. The other point to recognize is that the direct
injection of oil here will not eliminate the need for oil addition to the
charge. The reason is that the oil flow will be shut off for a substantial
part of the cycle. The tip seal will not effectively lubricate the
interface with residual oil this way. In a boundary lubrication situation
like this the oil has to be on the stationary part or else it will be wiped
away quickly. Only a small flood of oil from the tip seal would be as
effective as a slight wisp desposited evenly on the walls. Finally, the
side seals still need lube on the walls which is best provided by the
charge.
If someone wants to "fix apex seals" figure out how to get more effective
cooling. (P.S. this is not very difficult but requires complex machining
inside the rotor rather than the current thick cast walls.)
Jeff Spitzer
Boy am I glad I am not the only one that thinks the apex seals
need cooling :-) Remind me to give you a raise as unpaid
engineering editor.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 19:18:00 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Plan for reduction drive.
Bill Freeman wrote:
Gerry Hess wrote:
SNIP
. The softer teeth will be less
subject to spalling. The drag race crowd loves this tranny, too.
SNIP
Softer (I assume) means lower yield strength
and this will make spalling worse, not better.
Spalling is caused by fatigue in the tooth, specifically
(if you want to get technical) due to the Hertzian contact stresses exceeding
the infinite fatige life stress level. If this occurs in a short period of
time, the gear is way over loaded, i.e. too much torque. This is low/med cycle
fatigue if it it below some very large number of cycles. Hertzian contact
stresses occur slightly below the surface and cause the surface to flake
off in thin chunks. Are you sure you mean spalling? This has a very
specific technical meaning in tribology, and precision in language is
very important for technical discussions. I would expect excesive wear
and overheating and other boundary lube failure type of distress if the
lube was inadequate but not spalling. I see no reason that spalling
would be affected by lube except in the case of overheating the gear
and thereby undoing the heat-treatment and lowering the fatigue
strength to accelerate the fatigue process.
If you design a machine to operate at roughly 50% or lower ( depends on
the alloy) of the yield stress, it will NEVER fatigue, i.e. never spall.
It will wear out, but not by spalling. The most common place for
a layman to find spalling is in ballbearings - this is the std failure
mode for rolling element beargings due to high Hertzian contact stresses.
Bill
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______________________________________________________
Date: Mon, 18 Jan 1999 23:35:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Using VW engines in airplanes.
Bill Freeman wrote:
facilitator1@juno.com wrote:
Tracy, THX for info. being a diehard, i am going to
use 36 hp VW. Thot 1 rotor would be same wt.
Better over all. Fun etc. Virg
Say hi to Don, Beltronics, 1239 Main St
Along as you don't ask for more than 36 HP
and use a very light weight prop that VW ought to last
as long as any aircraft engine. Back in the days when I owned
a split window you could run that thing day in and day out
at its top speed of 72 MPH. :-)
You should *not* use the "36 hp" VW. Used up to '59 in
the cars. 60 thru 65 were 40 hp, also no parts available. Only
66 (Squareback) or 67 (Bug/Bus) and later have aftermarket
parts available. 36 hp has the generator support as a part
of the crankcase casting, all later models have it as a sep
part bolted on with 4 bolts.
Several reasons.
First, parts are nearly nonexestant, second it is MUCH
weaker structurally than the later 1500/1600cc motors, and
third - is VERY low on HP. (tiny ports, 1200 cc disp,etc)
No hot cams available. Crank is spindly, the 36 hp is a
souped up version of the original 25 hp motor.
I have built several AC VWs in the last couple of years
for other people and they are doing fine, pass most of
their competition, pull bigger props, etc..
Use a post '71 block with dual oil pressure reliefs, dual port
heads, the 009 centrifugal distributor and * no bigger* than
90.5 mm pistons and cyls. Have your machine work done
by Rimco in the LA area somewhere (Paul??) they are
both the best and cheapest (hard to believe). Use CIMA/Mahle
piston and cylinders, Glyco bearings, ** Only** use
Eaton or ATE or TRW exhaust valves. This is CRITICAL,
other brands fail early and will destroy the whole engine.
VW exh valve is near failure in normal cruise in a car,
must be top quality and valve clearance adjusted
*religiously* every 25 hrs. All work as per VW factory
shop manual, at minimum.
Good luck, check out Great Plains VW - they do a good
job with these motors. Expect max 55-60 hp reliably with
direct drive.
Bill
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______________________________________________________
Date: Mon, 18 Jan 1999 23:42:11 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Plan for reduction drive.
Gerry Hess wrote:
Thanks for the info, Bill. Spalling is probably a bad choice of words, but
what I saw in Tracy C.'s PSRU was similar looking so I used the discription.
Lack of proper lube was the problem, and caused a chipping, crumbling type
of damage. (boy, I'll blow them away with this technical jargon)
That was after 650 hours on Tracy's Ross PSRU Bill.
Paul
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______________________________________________________
Date: Mon, 18 Jan 1999 23:39:20 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ceramic Apex Seals
V. E. Welch wrote:
What are the benefits of ceramic apex seals and do you think they are worth
the additional cost for A/C use? Would it be advisable to get an oil pump
with a higher than stock output? Is the stock water pump ok or should it be
changed for a higher volume unit?
Thanks,
Vince
None of that will hurt. How important is money?
The ceramic apex seals alone run about $1200 for a complete
13B engine set.
The stock engine will work fine up to about 180 to 200 HP.
If you are turbo charging and are looking for more HP
the engine will need all of this kind of help it can get.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 13:43:25 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold,
Archie Frangoudis wrote:
I agree with the plastic intake. I had a little to do with the manufacture
of the Corvette manifold, and the casting process.
The manifold is actually made of Nylon with cast-in-place threaded inserts.
It uses the same basic intake ram tuning that we use in drag and circle
track racing, but due to the fact that a passenger car cannot have tubes jutting through
the hood, they are radiused so that the right side of the manifold feeds the
left side engine.
Not unlike Everett Hatch's Powersport.
BTW, Powersport was at OSH this year,(under new ownership), for those that
could not attend.
Archie
That's great info Archie. I am always happy to hear from
people with first hand knowledge on this hi-tech stuff. I am surprised
that Nylon will take the heat.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 20:39:24 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: IVO prop problems
V. E. Welch wrote:
Is there something that I/We should know about Ivo Props????????
Subject:Prop blade design
Date: Sun, 27 Sep 1998 10:35:20 -0700
I went to a Don Bates symposium on props at GS EAA Flyin.
I was impressed with what Don had to say.
I learned that I need to redesign my prop jig
so the pitch can be a non-linear function of the
prop radius.
Don's website is: http://www.innercite.com/~bateseng
email address is: bateseng@innercite.com
Here is a list of his computer programs.
He will also run them for you so you don't need to buy them.
Paul
PROP OPTlMlZER automatically designs propellers tor optimum
cruise and climb performance. Enter a starting propeller design:
diameter, pitch and activity factor plus your engine horsepower
versus rpm and aircraft weight, span and drag area. Then
select your desired performance objective such as maximum
speed and/or climb, CAFE score, payload or minimum
horsepower required. In a single run, the program computes
your aircraft cruise and climb performance and does all the
adjusting of variables to find the best propeller design.
Use the program to match your own propeller and aircraft
performance and solve for your aircraft equivalent flat plat drag
area. Then turn it loose to resize your propeller and find your
best performance. Saves the cost of buying unnecessary props.
Many builders try 3, 4 or more! Ybu could spend far more than
the cost of a program and still not know if your performance is
what it should be. Now solve this problem scientifically.
THREE PROP OPTIMIZER PROGRAMS
The ADVANCED program is based directly on NACA test data
proven reliable through years of use. Prop Optimizer
"Advances" this method to the modern computer age. Design
or select a propeller based on this classic NACA data for 2-, 3-
and 4-blade propellers. Clark Y and RAF-6 airfoils are built into
the program. The simplest version to use. It helped select the
propeller for the Formula I Bronze division winner at the 1993
Reno National Championship Air Races.
The PRO program enables detailed design and engineering
analysis for the more technically capable user. Specific user
airfoil characteristics may be input to finely tailor a propeller to
any application. For user convenience, the Eppler 850 series of
special propeller airfoils and Clark Y and RAF-6 airfoils are built-
in. The program is based on Classical Vortex theory. It includes
profile drag, Mach and Reynolds number and multi-blade
interference effects. It makes possible minimum induced loss
designs, detailed aerodynamic analysis and optimized blade
shaping and pitch distribution. Our most powerful program.
The STRENGTH program analyzes propellers and optimizes
thickness for minimum required strength and tip deflection. It is
built into both the Advanced and PRO program design
optimization. This program permits separate strength analysis
for existing propellers.
Diameter, pitch, activity factor
Pitch angle, Blade angles, Blade angle-of-attack
Efficiency, Advance ratio
Thrust, Drag, Thrust & Power loading distribution
Thrust & Power coefficients, Speed-Power coefficient
Tip speed, Tip Mach number
Cruise speed, Climb rate, Speed for max climb rate
Equivalent flat plate drag area
Thrust HP, HP required, HP available
Propeller rpm, Engine rpm, Gear reduction ratio
Airfoil coordinates, Carving block dimensions
SUMMARY OF PROP OPTIMIZER FEATURES
Opiimiize cruise and climb perf&rmance togethe?
Find best speed for maximum rate of climb
Find minimum horsepower required
Optimize reduction gear ratios
Compute aircraft drag and performance
System rather than piecemeal design optimization
Adjusts design variables automatically
Optimized repitching of an old prop
Matches propeller design precisely to your aircraft
Compute airfoil coordinates, angles and blade shape
Easy to use, eliminates tedious multi-run analysis
Subject: IVO prop
Date: Sun, 27 Sep 1998 10:43:33 -0700
BTW Don confirmed that the IVO prop lift coeff. goes negative
on the IVO prop out about a 20 inch radius at about 170 MPH.
This is why people are running into a brick wall using
this prop on a fast airplane. It actually tends to suck
air out of your cooling inlets.
Paul
Subject: IVO prop
Date: Sun, 27 Sep 1998 16:36:23 -0700
Neil A. Kruiswyk wrote:
Paul,
You've really caught my attention here!! I'm using an IVO but don;t
have that many hours on it to say how good or bad it is. A good friend of
mine used my prop on his long-eze for a couple of flights and reported max
speed at ~175kts which is about 10 lower than his Warneke knock-off. The
IVO was smoother and is adjustable but it seemed to clap out at the top end
for him. Me on the other hand, have had my Lancair at 185kts without much
problem. I have yet to run it with my new injection systems but I;m sure
theres going to be at least a 20kt improvement.
How did you determine a negative lift coefficient?
Neil
It was'nt me Neil. It was Mr. Don Bates
Here is how I understood it. Each airpalne has a unique fixed pitch prop design.
The input factors are max prop diameter avaialable, wingspan, flat plate drag
HP at some RPM, weight, etc.,etc.etc..
This gives a prop with a certain plan form, blade width distribution and
MOST IMPORTANT OF ALL TWIST DISTRIBUTION.
The twist distribution of the IVO prop is incorrect for fast airplanes.
Certain sections of to blade go into a negative angle of attack condition
at a beginning speed of around 170 MPH. This causes the
thrust to fall off drastically.
Check with Don for his version.
Paul
Subject: IVO prop
Date: Sun, 27 Sep 1998 17:38:19 -0700
Neil A. Kruiswyk wrote:
Paul,
Can you give me Don's e-mail addy? I'm wondering what I can do to
improve things.
Neil
You, Tracy and Dave all have the same problem. I would use blue foam and
epoxy to build a cuff around the root of the blades with a higher
pitch angle. The centrifugal loads on such a cuff are rather low compared
to everything well outboard along the radius. It should be no problem to
just epoxy it on. You should sand through the IVO gel coat first.
Use just one very thin layer of 4 oz fiberglass cloth to keep the weight down.
The aerodynamic loads are low in that area as well.
Test it on the ground at max static RPM. Stay within the pattern and dive
the airplane to VNE for a max RPM test. If one side comes off you can land
with the engine at idle.
If one side slings off the unbalance should be minimal because
the other side is so close to the hub.
Look at some pictures of turbo prop airplanes or a picture of a B50 (late model B29) for
examples.
Don's website is: http://www.innercite.com/~bateseng
email address is: bateseng@innercite.com
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 20:43:39 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Apex seal cooling
Jeff Spitzer wrote:
In regards to your comment about apex seal heating: On the Moller engine
we had evidence of apex seals running at up to 900 deg F during full power
operation. That's why the seals were made of tool steel. What's worse,
inconel springs would not last...we had to go to a material called Elgiloy
that has superior properties at extreme temperatures in a spring temper.
That problem of spring failure was made worse with brilliant multipiece
seal designs as they often forced gasses to pass through the spring area in
the seal slot in an attempt to limit the leak path. What a mistake! All
note: The Mazda engine does a much better job cooling the apex seals than
the Moller engine and these numbers don't apply to Mazda.
Jeff Spitzer
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______________________________________________________
Date: Wed, 20 Jan 1999 21:03:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil cooling
Perry Mick wrote:
I've got the stock oil cooler in my plane, haven't flown yet so I'm
not sure how sufficient my ducting is through it. But one thing I've
noticed in the car (I drive an '86) is that if I cruise down the
highway in fourth gear, such that the rpms are around 4500-5000, the
oil temperature in the pan climbs to 200 or 210 or more. (I've
added an oil temp probe in the car, in the oil pan where the temp
switch normally goes for subzero start assist- don't need that
in Oregon) And this is with air ramming in the flat face of the oil
cooler, which is going to be better at getting air through the cooler
than the horizontal arrangement in the plane.
Because of this, I was assuming I may have to add a second oil
cooler in series with the original, as is done in the 3rd gen RX-7.
But sounds like this hasn't been a problem for Tracy.
First I would try to get the oil cooler in the airplane as perpendicular
to the airstream as possible. Second you have a lot more airflow to
work with at 150 MPH than you do at 75 MPH. Probably four times as
much.
Proper cooling ducting is EVERYTHING in an airplane. If necessary
move the rads to the back of the plane where you can provide proper
P51 style ducting. That should give you enough room under the cowl
to properly duct the oil cooler.
Tracy has an auxilary cooler in the form of a water oil heat exchanger
in the pan. Take a look at the News Letter web site below for some
examples. Also see the web site for a link to a site that talks
about proper ducting.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 21:13:22 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: composite intake manifold.
Marvin Kaye wrote:
Paul,
I've been thinking seriously about a composite intake manifold, but don't
know of an epoxy with good high temp characteristics. If you or anyone
else out there knows of a good resin system that holds up well to heat, I'd
sure like to know more about it. (The epoxy which is presently used on the
Lancair kits gets pretty soft at high temps (we use a heat gun to soften
layups which need to be removed), and I wouldn't dream of trying to use it
for an intake manifold. I suspect, however, that there _is_ a product out
there which will perform at higher temps, just don't know who makes it or
where to get it.) Any suggestions along these lines will be greatly
appreciated.
TIA...
<Marv
All that cold air flowing through the manifold keeps it cool Marv.
As long as you shield it from the exhaust pipes and perhaps insulate
it I think it will be OK.
Nylon would never work if it was otherwise as it has a lower melting
temp. than epoxy. As I recall epoxy is good for at least 350 degrees.
That heat gun is probably good to 500 or 600 degrees.
Never the less send email to Klaus and ask him what he uses.
Klaus Savier <lse@west.net>
I think he mentioned he had some high temp stuff.
He tends to be a little secretive with me sometimes :-)
Let us know what he says.
Paul
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______________________________________________________
Date: Wed, 20 Jan 1999 21:17:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Hurley tip seals
Paul Yaw wrote:
Jeff Spitzer wrote:
I went to the Hurley engineering website to view the innovations there. I
humbly submit the following opinions:
snip......
If someone wants to "fix apex seals" figure out how to get more effective
cooling. (P.S. this is not very difficult but requires complex machining
inside the rotor rather than the current thick cast walls.)
Jeff Spitzer
I couldn't agree more!
Paul Yaw
Where you been Paul? There are a couple of guys looking for you
with engine questions. Check back a few days for messages.
Paul Lamar
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______________________________________________________
Date: Wed, 20 Jan 1999 21:30:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
Paul Yaw wrote:
Hi everybody,
Congratulations to Jeff Spitzer for adding another common sense opinion
to the apex seal discussion.
The best thing that anyone can do for a 6-port engine is to throw the
stock intake manifold into the trash. The ports don't flow all that
well to begin with, and the stock manifold reduces the flow by about
28%. It would be hard to build a worse manifold. If you construct your
manifold from pre-bent pieces with a 3" bend radius you will
SUBSTANTIALLY increase the airflow. Use a tubing diameter that is just
large enough to get the job done. In addition to poor airflow, the
6-port engine also suffers from low inlet velocity. There is simply way
too much cross sectional area for the airflow requirements of a 13B.
For instance, a peripheral port 13B, peaking at 9000rpm is happiest with
an inlet cross sectional area of about 2.8". A 13B meant to peak at
6500 rpm should have an inlet cross sectional area of about 2.0" I
don't have the numbers in front of me, but if I remember correctly, a
6-port engine has an inlet cross sectional area of approximately 2.5"
If you use 1.75" OD for the secondary ports, you can oval the end, and
stretch it a bit to make it fit over both ports. If you make the
flanges from .750" aluminum, this will give you plenty of room to shape
the transition from the tubing to the intake ports. For the primary
ports, 1.25" OD will work well, and you can oval the end just as you did
with the secondary ports. The inlet cross sectional area will still be
excessive, but at least you haven't made matters worse by using
oversized tubing.
If you use a plenum to mate the runners to a single
barrel throttle body, bring the runners into the plenum into a square
pattern rather than in a row. This will give the airflow a straighter
shot from the throttle body to the runners. Space the runners far
enough apart to allow for a generous radius on their inlet. As for
runner length, try to get at least 18". Don't worry about making them
too long. It is probably not possible. Hope this is of some help.
Paul Yaw
How much HP could we expect at 6000 RPM Paul?
Paul Lamar
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______________________________________________________
Date: Wed, 20 Jan 1999 21:34:00 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold.
Rodger Hilyard wrote:
Three things to consider if you make an epoxy/glass manifold tube.
(1) Use enough layers of bi-directional glass to insure that
the tube does not collapse under 29+ inches of engine vacuum at
maximum possible operating temp.
(2) Select an epoxy that has self extinguishing fire properties.
(3) Select an epoxy with a transition temp and a curing temp
that will maintain enough strength at operating temp+ to avoid
collapse as in condition #1.
BTW fuel will dissolve blue styrofoam and the unsticky side of
the gray (200 mph) duct tape will serve as an effective parting
agent.
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______________________________________________________
Date: Thu, 21 Jan 1999 00:57:10 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: EAA recognition for Tracy and Everett
larry k cox wrote:
Hi Paul,
I have been thinking along the same lines for a month or two, but didn't
know quite what to do with it. I thought I would get in touch with Mick
at Contact Mag. and see if he thought it was a good idea, but your
suggestion that we all write in to the EAA might be better.
Actually I was thinking more of Tracy and Lou Ross, since it seems like
to me Lou has made it possible for a lot of people to get into auto
engines with a lot more confidence and a lot less hassle. Plus if you
have ever met Lou, you would never find a nicer guy, and when I was
there a little over a year and a half ago his health seemed to be failing
fast, and it would be nice to give him the recognition he deserves while
he is still able to stand up receive it. He has been a great help to us
in our efforts.
However, I have no abjection to honoring Everett Hatch. I know less
about him, but I understand that his contribution has been great also.
It may take some time for me to get drawings of the Murphy Elite fire
wall and the location of the mount hard points. Murphy seems to be a
little hard to get drawing and dimensions from. They prefer to stick to
assembly instructions, rather than provide raw information.
Larry Cox lkcox2@juno.com
Delta Junction, Ak. 99737
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______________________________________________________
Date: Thu, 21 Jan 1999 01:03:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
Paul Yaw wrote:
Paul wrote:
How much HP could we expect at 6000 RPM Paul?
At 90% volumetric efficiency the engine would be drawing about 250 cfm.
90% should be a breeze with a good manifold. I tend to look at engines
in terms of cfm per horsepower which is just another way of stating
brake specific air consumption(BSAC). This can vary anywhere from 1.6
to 1.35 depending mostly on exhaust flow. A conservative number for a
stock exhaust port 13B with a free flowing exhaust system is 1.45. If
you divide that into 250 cfm you get 172.4 horsepower.
I think that 170
is a very safe estimation. It probably seems strange looking at
horsepower in these terms, but this is based on airflow numbers while
the engine is running on the dyno. The BSAC seems to be mostly affected
by exhaust efficiency, and this is mostly what I use it for. Since it
is a total efficiency number it can of course be affected by anything
from the ignition system to the oil pump drag, but for my application
these other factors tend to be relatively constant. In my experience,
adding stock (and most aftermarket) manifolds to the scrap pile will
give the greatest gains in volumetric efficiency.
Add to this some
intake and exhaust length tuning, and you can get nearly 100% VE without
a bridge or peripheral port. I always want to build a custom manifold
for my engines, but in most cases, class rules, or the customers pocket
book keep me from doing this. Unfortunately I spend a great deal of
time cutting manifolds into several pieces, grinding a lot, and then
welding them back together just so that the ports that I worked so hard
on can get some air. It is not uncommon to see a 20% drop in airflow
once the manifold is bolted on.
Paul Yaw
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______________________________________________________
Date: Thu, 21 Jan 1999 01:05:23 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil Temp
Chuck Dunlap wrote:
Perry Mick wrote:
I've got the stock oil cooler in my plane, haven't flown yet so I'm
not sure how sufficient my ducting is through it. But one thing I've
noticed in the car (I drive an '86) is that if I cruise down the
highway in fourth gear, such that the rpms are around 4500-5000, the
oil temperature in the pan climbs to 200 or 210 or more. (I've
added an oil temp probe in the car, in the oil pan where the temp
switch normally goes for subzero start assist- don't need that
in Oregon) And this is with air ramming in the flat face of the oil
cooler, which is going to be better at getting air through the cooler
than the horizontal arrangement in the plane.
Isn't 210 degree oil temp in the pan OK? Oil in this location has
already been heated by the rotors and has not been cooled yet. From
reading Tracy's manual, the oil temp redline should be 210 degrees
<after> the oil cooler.
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______________________________________________________
Date: Thu, 21 Jan 1999 01:09:16 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
George Moore wrote:
Paul Yaw,
Your intake manifold tips seemed straightforward, but would it be
possible to post a sketch of the manifold you are describing for a
single barrel throttle body for a 6 port engine ?
I would also like to see a HP curve Paul so we can perhaps make
a better decision on the PSRU reduction ratio.
If you don't have a scanner
you can FAX me at 310 475 5517 or mail to:
Paul Lamar
830 East Santa Maria St
Suite 303
Santa Paula CA
93060
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______________________________________________________
Date: Thu, 21 Jan 1999 02:25:30 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
I think we can learn a lot from what Mazda did on their
Le Mans engines.
According to SAE paper 920309 Mazda 4-Rotor Rotary Engine for
the Le Mans 24-Hour Endurance Race Mazda were getting about
120 HP per rotor or about 240 HP for a two rotor normally
aspirated engine like the 13B at 6000 RPM.
Obviously this engine had a volumetric efficency of
well over 100%.
Three percent of this power or 7.2 HP came from
the use of three spark plugs per rotor which leaves
232 HP.
This was achieved with an intake pipe length of
about 24 inches which gave a torque peak at
about 6400 RPM. A slightly longer pipe length
would be called for to lower the torque peak
to about 6000 RPM but may be counter productive.
I estimate from scaleing the engine drawing that the
intake pipe diameter was about two inches in diameter.
Admittedly this was with a peripheral port rotor housing
and a 10:1 compression ratio.
But we should be able to get at least 200 HP with
a street ported side port engine with a 9.6:1
compression ratio and a tuned intake manifold.
IMHO Tuning the intake manifold can result in a volumetric
efficiency of greater than 100%. In other words a mild
supercharge effect. According to Taylor as much as a
5% gain in volumetric efficency can come from keeping
the manifold cool by using a non-metalic manifold.
Of course supplying the induction system with cold
ram air will also help greatly.
I also think we need to differentiate measuring the
steady state airflow from the dynamic ram effect of a
tuned intake manifold.
Paul Lamar
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______________________________________________________
Date: Thu, 21 Jan 1999 02:28:37 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil cooling
Perry Mick wrote:
Paul wrote:
Tracy has an auxilary cooler in the form of a water oil heat
exchanger in the pan. Take a look at the News Letter web site below
for some examples. Also see the web site for a link to a site that
talks about proper ducting.
I have Tracy's book, but forgot about that idea.
Previously I mentioned that I was measuring oil temp in the pan.
But this is worst case temp as the oil has just drained from the
engine. The oil flows through the oil cooler before entering the
engine, so to see how well the oil cooler is performing it would be best
to measure the oil temp after the oil cooler, before it enters
the engine. Mazdatrix sells an adaptor to do this, part number 11802,
that mounts under the oil filter and has two ports, one for oil temp
and one for oil pressure.
I think I read on an RX-7 page that the max oil temp you want going
into the engine is 210, but not certain of that number, may need to
verify that.
I'm going to get two of these adaptors on order, one for the plane
and one for the car, to get more data.
Perry J. Mick
Mazda 13B-powered LongEz N7XR
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______________________________________________________
Date: Thu, 21 Jan 1999 08:47:26 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Another comment on knock sensors]
BCGARDNER@aol.com wrote:
Paul,
You recall the paper you recommended by Paul Ko that delineated the
differences between the various 13B blocks? Paul Ko commented this morning on
knock sensor location. FYI and the consideration of the group.
Thanks for all you do to promote aviation use of the rotary.
Barry Gardner
Paul Ko's comments:
Subj: Re: Knock Sensors
Date: 01/21/1999 4:06:06 AM Central Standard Time
From: pko@rosarita.engr.ucdavis.edu (Paul Ko)
To: fc3s@foci.com
On Mon, 18 Jan 1999, F8LDZZ wrote:
Knock sensor by the spark plugs gives it a closer shot to the combustion
chamber where ignition of the fuel mixture takes place. Of course, moving
it to the front rotor housing makes the sensor dedicated to the front
rotor only.
I don't think that is true. Only one knock sensor is required for the
whole engine because the whole engine will vibrate during detonation, no
matter where you mount the knock sensor. And also, knock sensors are
piezo-electric devices which can only detect its own resonant frequency,
which for the Mazda units, I recall, is ~3600Hz. If I remember
correctly, I don't think knock sensor can detect magnitude. They just
output a signal when it is vibrated at its resonant frequency.
Paul Ko
pko@engr.ucdavis.edu
http://www.engr.ucdavis.edu/~
Formula SAE UCDavis Team Captain
http://mae.engr.ucdavis.edu/~fsae
When you talk about knock sensors you have to talk about
the whole package including the electronics. Unless one is privy
to the source code in the engine computer one never really knows
what is going on. I suspect with a dedicated signal processing
computer all sorts of improvements can be made including detecting
magnitude and a wide range of frequencies. The regular engine computer
just does not have enough time left over while doing its regular chores
to analyise the knock sensor signal in detail.
The car manufacturers guard this source code religiously and release it
to nobody except under court order.
With one or more dedicated signal processor(s) I am sure there would be a signal
to noise ratio advantage of having two knock sensors located close
to the source of the knock. That is why Mazda moved them in the first
place.
Paul
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______________________________________________________
Date: Thu, 21 Jan 1999 08:50:25 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold.
Anderson Ed wrote:
Your right, Paul, maybe the slot would improve the airflow{:>}.
To change the subject slightly, I mentioned my success with my last mod
to the oil cooler airflow situation. Well, it turns out while it was
great on a 15F OAT day, it was not so good when them temps rose into the
40-50F range. Still much better than before, but again at high
sustained power settings it rose above my 210F redline. Also, as you
probably read, Tracy who is using the stock oil cooler is actually
having his oil run a little too cool in some power settings. So, I got
to looking at the stock mazda oil cooler and comparing it to my Earl's
performance one installed.
I may have found a reason why my cooler does not appear to handle the
heat rejection as well as the stock one and wanted to run my findings
and logic by you and other folks on the list.
I noticed that the stock Mazda oil cooler is actually set up as a Cross
flow in that the oil cooler is divided so that oil comes in one end and
runs 19 1/2 inches down a set of three rows to the opposite end and then
flows back 19 1/2 inches through four bottom rows to the entry/exit
end. So all total the oil flows through 39 inches of oil cooler tube
while in the stock mazda cooler. On my cooler the oil flow is
"standard" in that it flows through 25 rows 11 inches long.
I assumed 0.5 Gallon/Minute of oil flow and 1/2 " dia for my -10 hose
that I am using. I then calculated the oil flow rate in inches/minute
(using 0.5 G/M) in the 1/2 inch hose and came up with 588 inches/minute
or 9.8 inches/second. Using that figure for oil flow velocity, I
calculated that the oil in my Earls cooler stays in the cooler 1.121
seconds while with the 39 inches of row in the mazda cooler it stays in
the that cooler for 3.97 seconds. Now since the oil is only being
cooled the time it is in the cooler, the conclusion I draw is that the
three fold longer stay in the cooling rows of the stock oil cooler may
be the reason why the stock cooler gives more cooling than my Earls
cooler, even thought they have equivalent cooling fin area.
If this reasoning does not have a fatal flaw in my logic or
calculations, it would mean I would need almost three times the fin area
in a Earls' cooler to match the stock Mazda cross flow cooler.
Ergo! I may find the solution to my oil temp problem is to replace my
Earl's with the stock oil cooler.
Comments???
Ed Anderson
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______________________________________________________
Date: Thu, 21 Jan 1999 08:52:10 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
Anderson Ed wrote:
Paul,
I got out my CAD drawings of my homemade intake manifold and discovered
that my intake route is almost exactly 12" from intake port on the block
to the base of the throttle body. Someone, perhaps you, mentioned that
PowerSport found that 12" killed performance - something about
standoff? And now based on what Paul Yaw has mentioned, it appears that
my missing HP may be indeed be in the intake manifold. Lets' see 18"
where I now have 12"?? Hummmm. Certainly interested in what Paul says
about HP at 6000 rpm for a six port.
Also, if you do get a response to the high temp expoxy, please let me
know.
Ed Anderson
Ed
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______________________________________________________
Date: Thu, 21 Jan 1999 10:24:24 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Composite intake manifold. Epoxy temp.
Anderson Ed wrote:
Rodger,
Sounds like excellent recommendations, now if we just knew of the
expoxy that met that criteria, I would be set to try it. Would you
happen to have some candidates in mind??
Ed Anderson
I called Klaus and he recommended calling Shell.
(800) Tec Epon or (800) 832 3766
Then my second telephone line went down. So somebody give it
a try please. The telephone company appears to be working on
my second line.
Characteristicly Klaus would not tell me what he used on
his O-200 sump :-)
He did say you should heat cure the hi temp epoxy after you get
the foam out.
He mentioned that Vinyl Ester resin as used in the GlasAirs
is good to 210 to 220 degrees F. Confirmed by the
Aircraft Spruce catalog. The problem with that is it
desolves blue styrofoam. If you use some other type of
foam you may have a problem digging it out.
The 98-99 A/C spruce catalog list MGS epoxy system 285 good to
221 to 230 degrees F. EZ-poxy with a post cure of
two hours at 150 degrees F is good to 196 deg F.
If you isolate the composite part of the manifold
from the flange and pipe part with silicon hose and hose clamps
and shield and insulate it from the exhaust heat I doubt if
the temp. of the manifold will get much over 100 degrees F.
You can check by putting your hand on any intake manifold
while the engine is running.
Paul
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______________________________________________________
Date: Thu, 21 Jan 1999 10:29:32 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Did a rod break?
MAR34807@aol.com wrote:
It was just a random fatal accident I picked out of this
months NTSB report. Nothing to do with homebuilding.
I think you are quoting the accident in which a friend of mine (my original
private/instrument flight instructor and now/was a PIC instrument instructor-
named flight instructor of the year in 97!) was killed this month in a Lake in
NH from just something that sounds like this! He was able to save the
"customer" whose plane it was-last I heard.
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______________________________________________________
Date: Thu, 21 Jan 1999 10:28:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
Anderson Ed wrote:
Based on Paul Yaw comment on reasonable expectation for HP from a 13B
six port, it is becoming clearer that my boat anchor slab manifold which
I tried to match as close as possible to the stock manifold is where I
am likely to find my missing 22.4 horse power. I believe my 2" dia
exhaust pipes, one for each port and straight thru (old glass pack but
with ceramic packing) mufflers for each pipe is probably not the
problem.
With Pauls suggestions about intake pipe sizes, it should not take long
to come up with a new intake manifold with better flow and much lighter.
Thanks Gents
Ed Anderson
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______________________________________________________
Date: Thu, 21 Jan 1999 10:31:16 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
StJames515@aol.com wrote:
Great Stuff, Paul!
Paul wrote:
IMHO Tuning the intake manifold can result in a volumetric
efficiency of greater than 100%. In other words a mild
supercharge effect.
How about the dynamic chamber to gain the supercharge effect with a shorter
(more managable in aircraft) induction tube length? Tracy Crook has used this
with positive (how much?) benefit on his RV4.
Best of Everthing
Tommy James
I'll let Tracy comment on that. I know he got more power.
Paul
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______________________________________________________
Date: Thu, 21 Jan 1999 11:10:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: [Fwd: True Displacment?????]
Anderson Ed wrote:
Paul, I have what is probably a rather dumb question (not that that is
too unusual for me) about the dispacement of a 13B. The reason for the
question is I am try to calculate airflow thru a rotor motor.
I am using 1300 cc or 80 CID as the basic displacement and do not know
if that is correct for the true displacment of the the 13B or is some
equivalent. To further explain my question the following:
My calculation involves the displacement of each rotor face. I taking
the 80 CID and dividing by two to get displacement per rotor = 40 CID
and then by 3(number of faces per rotor) to get displacement per rotor
face. 80/2/3 = 13.88 CID.
Now if that is factual, I should be able to get the aiflow at 6000 rpm
by the following: At 6000 rpm eccentric shaft I have 2000 rpm for the
rotors. If each rotor face is 1/6 of the total displacment of 80 CID
then the a single rotor face volume is 13.88 CID and since each rotor
face would make a complete rotation during 1 revolution of the rotor.
Then at 2000 rotor rpm the airflow (assuming 100% Volumetric efficiency)
would appear to be:
CID_per_Face*Number_faces_per_rotor*Number_rotors*RPM_of_rotor/1728 =
airflow CFM. or 13.88*3*2*2000/1728= 96 CFM airflow at 6000rpm eccentric
shaft (2000 rpm rotors).
However, we know that the airflow at 6000 rpm is certainly in the
250-300 CFM range verses 96 CFM. So my question is - is the typical
1300cc or 80CID figure commonly used for the 13B the actual displacement
or is it only an equivalent displacement???? And if an equivalent
displacement, what is the actual displacment or the displacement of one
rotor face as it draws in air and goes through its cycle. I read
somewhere that the actual equivalent displacement of a 13B compared to a
recriporcating engine was around 2100cc, but there was no explanation at
how they arrived at that.
Where am I screwing Up????
Ed Anderson
Here is a trick to clarify your thinking about the
displacement of the rotary engine.
Make a scale drawing of the side view of the engine
1/4 by 1/4 graph paper. Another way is to scale up a
copy of a side view of the engine untill it matches the external
dimensions of the engine. See the picture below. It is the top
chamber in question.
Count the little 1/4 by 1/4 squares. Multiply that number
by 16 to get the number of square inches of side area.
Multiply that number by the width of the rotor and you have
the displacement of one chamber. I cheated in calculus by
this method :-)
The rotor fires once per rev of the output shaft...
just like a two cycle, one cylinder piston engine. So the
displacement of a 13B (what ever you make of it)
is equal to a two cylinder two cycle engine.
In racing they equate it to a four cycle with twice
the rotary displacement.
Paul
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______________________________________________________
Date: Thu, 21 Jan 1999 11:18:37 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Geschwender Hy-Vo drives
Lonnie Wood wrote:
Paul,
There was an article in Sport Aviation, March 97 on Fred
He has been building Hy-Vo Chain drives for a long time. He claims
never to have had a failure..
There is also a company in Washington, Aero Kinetics, that seems to
be doing very well with their chain drives.
I think the chain drive should not be discounted. It seems from their
experiences that they can work quite well.
In my plane the 8" offset worked out quite well to get the prop up higher out
of the weeds.
There is also the wee bit of advantage of producing less heat and a slight
bit more efficient than gears, but who's counting?
Lonnie
rwood@iceinternet.com
I am sure it well Lonnie. Fred Geschwender passed away.
I doubt the more efficient (heat) bit Lonnie. There is no beating a
stright cut single reduction spur gear.
Calculate the increase in that eight inch offset for the aluminum
housing at a temp of about 220 degrees F compared to room temp.
That should give you a minimum dimension on the room temp
slack required by the chain.
Paul
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______________________________________________________
Date: Thu, 21 Jan 1999 11:20:00 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Composite intake manifold.
Archie Frangoudis wrote:
After reading this message,let me respond to the Nylon manifold we designed for GM.
It is Nylon based, the remainder is proprietary.(or was at the time. Almost four years ago).
Hope I did not mislead readers. The same material is used for Valve covers,
and Timing chain covers.
Archie
--
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______________________________________________________
Date: Thu, 21 Jan 1999 11:21:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Turrentine 13b rebuild tape
tom wrote:
Got the tape yesterday. Its actually 2 tapes. Quality is PRETTY good,
definitely good enough for the purpose intended. Great info so far, but I
haven't had a chance to watch much yet. I wasn't expecting 2 tapes, so
there must be a lot of info there. I will post a thorough review later.
tom
Tom Jelly, HSBC Futures at the CME 312-559-1057 7am-2pm. 773-348-6549
(H) 773-206-6764 (cell)
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______________________________________________________
Date: Thu, 21 Jan 1999 11:37:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake Manifolds
Chuck Dunlap wrote:
I am running a 13B with stock lower intake manifold with injectors ala
Tracy Crook's setup. My first attemp was with a squarish aluminum
built-up plenum that just sat on top of the lower manifold with throttle
body underneath to the side. I got 4200 static RPM. I was disappointed.
I then built a new manifold with the plenum on the other side near the
plugs. (This is an upright installation.) The new manifold is about 24"
between intake ports and throttle body, with two 1-1/4" primary tubes
and two 1-1/2" secondary tubes. I now get 4700 RPM static. Much better.
The throttle body is off a 300ZX Nissan. This is with a 70" Performance
Prop and 2.17 Ross redrive. Clark (the prop maker) says this is a 15 to
20 HP gain. This confirms what I have read about the intake being very
responsive to tuning. Thanks to everyone for all the good info flowing
from this list- it sure helps everyone to not have to "re-invent the
wheel" by duplicating efforts.
Chuck Dunlap RV-6 S.E. Arizona
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______________________________________________________
Date: Thu, 21 Jan 1999 11:48:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: True Displacment?????
Anderson Ed wrote:
Thanks Paul, I understand your technique to get the volume of a chamber
(worked for me in Calculue as well {:>}). Apparently I was trying tocompare the rotor flat area to the displacement of a piston where as If
I understand you correctly it is the volume of the chamber of a rotor
housing or rather the volume of the rotor in the chamber. I think each
chamber is around 640 CCM. I follow the anology to a two cylinder/two
cycle piston engine. I believe the anlogy to a four cycle with twice the
displacement. But, just wanted to figure how much air it pumped.
So I believe If I am following you, my calculations should not consider
6 faces on 2 rotors so much as two rotors of 640 CCM displacement each
revolving at 1/3 the eccentric shaft rpm.
Ok let me go chew on that a while
Thanks, again
Ed
Paul wrote:
Anderson Ed wrote:
Paul, I have what is probably a rather dumb question (not that that is
too unusual for me) about the dispacement of a 13B. The reason for the
question is I am try to calculate airflow thru a rotor motor.
I am using 1300 cc or 80 CID as the basic displacement and do not know
if that is correct for the true displacment of the the 13B or is some
equivalent. To further explain my question the following:
My calculation involves the displacement of each rotor face. I taking
the 80 CID and dividing by two to get displacement per rotor = 40 CID
and then by 3(number of faces per rotor) to get displacement per rotor
face. 80/2/3 = 13.88 CID.
Now if that is factual, I should be able to get the aiflow at 6000 rpm
by the following: At 6000 rpm eccentric shaft I have 2000 rpm for the
rotors. If each rotor face is 1/6 of the total displacment of 80 CID
then the a single rotor face volume is 13.88 CID and since each rotor
face would make a complete rotation during 1 revolution of the rotor.
Then at 2000 rotor rpm the airflow (assuming 100% Volumetric efficiency)
would appear to be:
CID_per_Face*Number_faces_per_rotor*Number_rotors*RPM_of_rotor/1728 =
airflow CFM. or 13.88*3*2*2000/1728= 96 CFM airflow at 6000rpm eccentric
shaft (2000 rpm rotors).
However, we know that the airflow at 6000 rpm is certainly in the
250-300 CFM range verses 96 CFM. So my question is - is the typical
1300cc or 80CID figure commonly used for the 13B the actual displacement
or is it only an equivalent displacement???? And if an equivalent
displacement, what is the actual displacment or the displacement of one
rotor face as it draws in air and goes through its cycle. I read
somewhere that the actual equivalent displacement of a 13B compared to a
recriporcating engine was around 2100cc, but there was no explanation at
how they arrived at that.
Where am I screwing Up????
Ed Anderson
Here is a trick to clarify your thinking about the
displacement of the rotary engine.
Make a scale drawing of the side view of the engine
1/4 by 1/4 graph paper. Another way is to scale up a
copy of a side view of the engine untill it matches the external
dimensions of the engine. See the picture below. It is the top
chamber in question.
Count the little 1/4 by 1/4 squares. Multiply that number
by 16 to get the number of square inches of side area.
Multiply that number by the width of the rotor and you have
the displacement of one chamber. I cheated in calculus by
this method :-)
The rotor fires once per rev of the output shaft...
just like a two cycle, one cylinder piston engine. So the
displacement of a 13B (what ever you make of it)
is equal to a two cylinder two cycle engine.
In racing they equate it to a four cycle with twice
the rotary displacement.
Paul
What I have trouble with is equating the rate of the chamber
changing volume to that of a piston engine changing volume.
The tuning of a piston engine is frequently related to the piston
speed so a lot of work tuning piston engines is tough
to apply to the rotary. I think the best approach is pay
attention to what Mazda has done.
Paul
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______________________________________________________
Date: Thu, 21 Jan 1999 12:02:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
Jeff Spitzer wrote:
At 02:25 AM 1/21/99 -0800, you wrote:
Obviously this engine had a volumetric efficency of
well over 100%.
<snip>
IMHO Tuning the intake manifold can result in a volumetric
efficiency of greater than 100%. In other words a mild
supercharge effect.
<snip>
The Moller engne acheived 130% V.E. with tuned intake and exhaust. The
exhaust tuning was much more important than intake and port overlap is
extremely important too.
Jeff Spitzer
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______________________________________________________
Date: Thu, 21 Jan 1999 12:07:10 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold.
Jeff Spitzer wrote:
Anderson Ed wrote:
I noticed that the stock Mazda oil cooler is actually set up as a Cross
flow in that the oil cooler is divided so that oil comes in one end and
runs 19 1/2 inches down a set of three rows to the opposite end and then
flows back 19 1/2 inches through four bottom rows to the entry/exit
end. So all total the oil flows through 39 inches of oil cooler tube
while in the stock mazda cooler. On my cooler the oil flow is
"standard" in that it flows through 25 rows 11 inches long.
Heat exchangers are not designed on a time or
distance criteria. The main things that matter are fin
type/density/construction and temperature differential. The Earl's cooler
is actually superior in basic calcs because the hot oil is in contact with
more air while it is still hot. In the stock cooler the oil cools as it
flows through the 39" of length and by the time it gets to the end the
effectiveness of the heat exchanger (due to temp diff) is greatly reduced.
If the two units have about the same face area and the Earl's cools less
then it is definately from poor airflow and not cooler design. BTW, the
"ideal" cooler is a type called counter-flow. If you can image the air
flowing from front to back and the oil flowing from back to front (not side
to side as in your cross flow alternatives) then the hot oil would be
cooled by the heated air and the cooled oil would be cooled by the fresh,
cool air. These heat exchangers have the best package and cooling
efficiency.
Jeff Spitzer
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______________________________________________________
Date: Thu, 21 Jan 1999 12:46:25 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: True Displacment?????
Jeff Spitzer wrote:
At 11:10 AM 1/21/99 -0800, you wrote:
Anderson Ed wrote:
Paul, I have what is probably a rather dumb question (not that that is
too unusual for me) about the displacement of a 13B.
I think the 1300 cc is the displacement of one crank rotation. Use that
and see if your airflow numbers come out right.
Jeff Spitzer
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______________________________________________________
Date: Thu, 21 Jan 1999 12:46:25 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: True Displacment?????
Jeff Spitzer wrote:
At 11:10 AM 1/21/99 -0800, you wrote:
Anderson Ed wrote:
Paul, I have what is probably a rather dumb question (not that that is
too unusual for me) about the displacement of a 13B.
I think the 1300 cc is the displacement of one crank rotation. Use that
and see if your airflow numbers come out right.
Jeff Spitzer
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______________________________________________________
Date: Thu, 21 Jan 1999 12:48:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Prop pich and static RPM
Anderson Ed wrote:
Chuck
I have a 68 inch x 72 inch pitch prop from Clark Lydick (Performance
Propellers) and turn 5000 rpms static. I noticed your prop is 2" longer
which would obviously create more load and lower your static RPM, so
4700 does not sound bad. What is the pitch of your prop??
Ed Anderson
RV-6A
Vienna, VA
Paul wrote:
Chuck Dunlap wrote:
I am running a 13B with stock lower intake manifold with injectors ala
Tracy Crook's setup. My first attemp was with a squarish aluminum
built-up plenum that just sat on top of the lower manifold with throttle
body underneath to the side. I got 4200 static RPM. I was disappointed.
I then built a new manifold with the plenum on the other side near the
plugs. (This is an upright installation.) The new manifold is about 24"
between intake ports and throttle body, with two 1-1/4" primary tubes
and two 1-1/2" secondary tubes. I now get 4700 RPM static. Much better.
The throttle body is off a 300ZX Nissan. This is with a 70" Performance
Prop and 2.17 Ross redrive. Clark (the prop maker) says this is a 15 to
20 HP gain. This confirms what I have read about the intake being very
responsive to tuning. Thanks to everyone for all the good info flowing
from this list- it sure helps everyone to not have to "re-invent the
wheel" by duplicating efforts.
Chuck Dunlap RV-6 S.E. Arizona
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______________________________________________________
Date: Thu, 21 Jan 1999 13:38:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ed Anderson's Performance composite intake manifold.
Anderson Ed wrote:
Ah Shucks! Once again, true knowledge and understanding transends
mathematics.
Thanks Jeff, I was just about to start getting serious about yanking out
the Earl unit and sticking in the Stock Mazda cooler.
I understand the greater efficiency due to greater temp differential
between the oil and air with the Earl unit and decreasing with the mazda
unit as the oil temp continued to decrease over the 39" length. But
guess I thought the longer dwell in the longer tube length of the Mazda
unit would provide an net increase in heat removed from the oil. But in
the one case I have the heat of the oil being rejected by 25 11" rows
compared to 3.5 39" rows.
If I could restate my understanding of what I think I heard you say.
Because I have twenty five 11" rows in the Earl, the greater temp
difference maintained between the oil and air over the shorter lenght of
the 11" x 25 rows should result in more heat being transferred from the
oil to the air than would result from the 3.5 39" long rows of the Mazda
unit due to the decreasing temp difference between the oil and air (as
the oil continued to cool flowing down that longer length)all else being
equal.
Trying a different viewpoint, I have 25x11 =275 linear inches of oil
tube/row with the earl unit and 3.5x39=136 linear inches of oil tube/row
with the mazda unit. Therefore assuming same size or tubes and number
of fins attached to both units, then again it would appear that the Earl
unit is superior in heat transfer capacity.
So, it looks like back to the aiflow side of the problem, sigh!
Seriously , thanks again Jeff, I do appreciate your insight.
Ed Anderson
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______________________________________________________
Date: Thu, 21 Jan 1999 14:11:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Displacement II???
Anderson Ed wrote:
Ok Paul, I went back after your comments and scratched my head some more
on calculating airflow for a rotary. Based on your comment and some
info I got off the Webring/rotary net this what I now have.
Comments???
1. Each rotor chamber displaces 40 cubic inches
2. Each chamber volume is displaced 3 times during one rotor rev
(apparently each face is consider to have swept the entire volume during
the one revolution) or 40x3=120 CID
3. With two rotors this displacement equals 120x2=240 cubic inches of
displacement during one rev of the two rotors
I think you are off here Ed. Perhaps by a factor of two.
One gulp of air comes in and is burned once per rev per rotor.
Forget the three faces on the the rotor. They just confuse
the heck out of the issue :-) Paul
4. Assuming 6000 rpm eccentric shaft then rotor rpm = 6000/3=2000 rpm
5. 240 CID x 2000 rpm/1728= 277 CFM of air displaced at 6000 rpm
eccentric shaft which is close to what I hear mentioned for 6000.
6. Paul Yaw stated today that a stock 13B with
90% volumertic efficiency should produce 172HP.
7. Plugging this into the spreadsheet I get 278 CFM airflow
which with a 13.5 Air/fuel ratio gives 176 HP which is close to the
power Paul Yaw stated HP of 172 HP.
OR
8. I may have completely misunderstood what was explained to me and
all the above is garbage.
That is the best I can do for now. I hope to get a formula from the
engine experts that will either subtantiate the above or give me formula
for calculating airflow based on the phyical airpump characteristics of
the rotor motor. This should not be so hard! I think I am going to go
fly and forget this head scratching for a while {:>}
So many questions, so little understanding
Ed Anderson
Appreciate your question and if the spreadsheet is going to be useful
then I need to make certain I understand how the air pump works.
Ed
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______________________________________________________
Date: Thu, 21 Jan 1999 16:10:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Displacement II???
Anderson Ed wrote:
You are probably correct. But, I guess I am puzzel a bit by why
calculating the airflow of a rotary is apparently so difficult. It is
certainly straight forward with a recripocating engine. I mean we have a
phyiscal form moving (rotating) and we know the dimensions of it (don't
we?). If so much air "Y" is displaced per rotor revolution then "Y" x
RPM should get us close to the airflow, shouldn't it. This was the only
"Logic" I could use to get the calculations to give me around 250 CFM at
6000 rpm eccentric shaft.
Common you engine guys - is it impossible to calculate the rotor airflow
based on physical principals - just difficult or what????
Thanks
Ed Anderson
Think of it this way Ed. The intake stroke starts when the eccentric is
pointin West. It ends when it is pointing North. Compression ends
when it is pointing East. Expansion ends when it is pointing South.
and Exhaust ends when it is pointing West again.
Don't even think about the rotor turning on the eccentric shaft.
Think of it as a two cylinder two cycle engine.
So displacement is one chamber displacement times two for a two
rotor. It pumps twice as much air as as four cycle piston engine and so
does a two cycle piston engine with the same displacement
Paul
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______________________________________________________
Date: Thu, 21 Jan 1999 16:29:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Displacement II???
Brent Regan wrote:
C'mon guys.
Each rotor displaces 40 cubic inches per E-shaft revolution
A 13B (1300 cc) displaced 80 cubic inches per E-shaft revolution.
It takes the E-shaft 3 rotations to turn the rotor once.
The confusion comes because 4 stroke engines' displacement is based on TWO
revolutions of the crank.
Good point.... well put.
A 200 cubic inch 4 stroke engine displaces 100 cubic
inches per revolution OF THE CRANK. This is why race sanctioning bodies
handicap rotaries by 2X on displacement. It allows a displacement per
revolution comparison.
All bow down in the face of the truth.
Brent
Thanks Brent.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 00:07:42 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: True Displacment
Paul Yaw wrote:
Hi everyone,
The exact displacement is 1308 c.c., or 79.82 c.i. With a compression
ratio of 9.4:1 the volume at top dead center is 4.75 c.i. The volume at
bottom dead center is 44.66 c.i. The difference between the two volumes
(39.91) is the displacement per rotor, per revolution. Since the
difference between 80 c.i., and 79.82 c.i. is only a few tenths of a
percent, 80 c.i. is the number that is normally stated. So
(80Xrpm)/1728 is the airflow at 100 percent volumetric efficiency.
Plain and simple.
Paul Yaw
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______________________________________________________
Date: Fri, 22 Jan 1999 00:06:11 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil Temp
Tracy Crook wrote:
Isn't 210 degree oil temp in the pan OK? Oil in this location has
already been heated by the rotors and has not been cooled yet. From
reading Tracy's manual, the oil temp redline should be 210 degrees
<after> the oil cooler.
210 degrees in the pan is no problem at all. There is around a 25 - 30
degree drop after the oil cooler if things are working right. I have temp
probes in both places.
Measuring this differential might be the best way to gauge the effectiveness
of oil cooler installations. BTW, Do you know what the difference is on
your engine Ed (Anderson)?
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Fri, 22 Jan 1999 00:12:11 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
Tracy Crook wrote:
Well , I was going to stay out of this one but since you ask......
I think we must remember there are two different methods of tuning at work
here.
The tuned pipe manifold that has been the major topic of discussion on this
thread depends almost entirely on inertial effects (once the air starts
moving in the pipe it wants to stay in motion) and the resonant frequency of
the pipe. (major simplification here) This is certainly a legitimate method
of increasing volumetric efficiency but it has certain drawbacks. One is
that the improvement works over a small range of engine speeds (and as has
been pointed out, actually hurts at others) and the pipe length is rather
long at the engine speeds we want in aircraft use.
The other method (the one I designed around) is the "Dynamic Chamber"
effect as described in Kenichi Yamamoto's book. I reprinted the charts
showing how this worked at the end of my conversion manual. The full
explanation of this effect would require a much longer message than this but
if you study and understand what is going on here, you will see that it
depends on the fortuitous timing between the two rotors in the 13B. (note
that this will NOT work on a three rotor 20B due to the different timing
relationships between rotors). One really nice thing about it is that it
is a broad band effect. It works at ALL engine speeds and has none of the
"dead spots" of the tuned pipe.
The Dynamic Chamber can also take advantage of runner tuning effects as
well. And as a bonus, the tuning in a manifold of this type uses the
combined runner length of BOTH rotors thus cutting the required length for a
given engine speed in half compared to the tuned pipe manifold.
If this sounds like so much wishful thinking, take a careful look at engine
specs of the 88 and 89 normally aspirated RX7. The 88 was rated at 146 HP
while the 89 was 160 or 165 (I've seen both figures mentioned). Note that
power was specified at 6500 RPM in both cases. The really interesting part
is how the increase was achieved. The compression ratio increase from 9.4
to 9.7 had no significant effect. The horsepower gain was the result of a
couple of barrel valves placed in the intake manifold which SHORTENED the
runner length at engine speeds above 4000 rpm. What is really amazing is
that all these tuning devices worked in Mazda's stock manifold. Paul Yaw is
absolutely correct about it being a terrible implementation. The ideas were
excellent but the execution sucked.
A related factoid often overlooked in Mazda's manifold design is that much
of the tuning was aimed at increasing the engine torque between 2500 and
3500 RPM. This is the rpm range where the engine actually lives in the car
and torque here determines how powerful the engine is perceived to be by the
average driver. We, of course, care almost nothing about these engine
speeds.
I will soon have some more data on this subject. Today I bolted on (my test
stand engine) a manifold with Dynamic chamber with what most people would
consider ridiculously short runners. It is aimed at engine speeds of 7000
rpm and is made of fiberglass. First run is planned for a week or so from
now. If it works it will soon be flying on a Glasair.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Fri, 22 Jan 1999 00:20:14 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: True Displacment?????
Tracy Crook wrote:
In reply to Ed's question about 13B displacement, I think of it like this:
The engine processes (burns) its rated displacement (1308 cc or 80 cubic
inches) of fuel / air mixture on each turn of the crank. This is the same
as a piston engine of exactly twice the displacement since only half the
cylinders fire in one revolution.
Pauls two stroke analogy works pretty well too.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Fri, 22 Jan 1999 00:22:21 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Modifying the ports on a six port engine.
Finn Lassen wrote:
Anderson Ed wrote:
Yes, it is the 6 port 13B. However, the torque tube airflow tubes have
been removed as I did not feel I need much low RPM torque.
Ed, did you (or the guy who did the porting for you) smooth out the sharp
corner/end of the torque tube openings/tunnels?
Unlike Tracy, I actually removed the tubes, and poured JB-weld down there at
at 45 degree angle for a relatively smooth transition.
Finn
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Date: Fri, 22 Jan 1999 01:09:05 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Tracy Crook's dynamic effect intake system.
Tracy Crook wrote:
snip........
The other method (the one I designed around) is the "Dynamic Chamber"
effect as described in Kenichi Yamamoto's book. I reprinted the charts
showing how this worked at the end of my conversion manual. The full
explanation of this effect would require a much longer message than this but
if you study and understand what is going on here, you will see that it
depends on the fortuitous timing between the two rotors in the 13B. (note
that this will NOT work on a three rotor 20B due to the different timing
relationships between rotors). One really nice thing about it is that it
is a broad band effect. It works at ALL engine speeds and has none of the
"dead spots" of the tuned pipe.
The Dynamic Chamber can also take advantage of runner tuning effects as
well. And as a bonus, the tuning in a manifold of this type uses the
combined runner length of BOTH rotors thus cutting the required length for a
given engine speed in half compared to the tuned pipe manifold.
If this sounds like so much wishful thinking, take a careful look at engine
specs of the 88 and 89 normally aspirated RX7. The 88 was rated at 146 HP
while the 89 was 160 or 165 (I've seen both figures mentioned). Note that
power was specified at 6500 RPM in both cases. The really interesting part
is how the increase was achieved. The compression ratio increase from 9.4
to 9.7 had no significant effect. The horsepower gain was the result of a
couple of barrel valves placed in the intake manifold which SHORTENED the
runner length at engine speeds above 4000 rpm. What is really amazing is
that all these tuning devices worked in Mazda's stock manifold. Paul Yaw is
absolutely correct about it being a terrible implementation. The ideas were
excellent but the execution sucked.
A related factoid often overlooked in Mazda's manifold design is that much
of the tuning was aimed at increasing the engine torque between 2500 and
3500 RPM. This is the rpm range where the engine actually lives in the car
and torque here determines how powerful the engine is perceived to be by the
average driver. We, of course, care almost nothing about these engine
speeds.
I will soon have some more data on this subject. Today I bolted on (my test
stand engine) a manifold with Dynamic chamber with what most people would
consider ridiculously short runners. It is aimed at engine speeds of 7000
rpm and is made of fiberglass. First run is planned for a week or so from
now. If it works it will soon be flying on a Glasair.
Tracy Crook rws@altavista.net
Here is a diagram to go along with Tracy's description. It appears
to me the diagram is labeled wrongly. The upper one should be
the high speed configuration and the lower one should be the low speed
configuration. There is a diagram of the effects on the next page
that bear me out on this contention. The stock rotary valve Tracy mentioned
is clearly shown. It is not necessary in an aircraft engine (as Tracy
mentioned) as we don't care about power or BSFC at much less than 5000
RPM.
Pressure pulses in intake manifolds travel at the speed
of sound more or less. So for high speeds short distances are indicated
and for low speeds long distances are indicated. This is why we need
long pipes for conventional pipe tuning at 6000 RPM.
This diagram is from SAE paper 900036 New Technology Employed for the
Latest 13B-Rotary Engine.
These are two rotor engines that have been butterflyed for the sake of
illustration. They are not two... one rotor engines :-)
Tracy.... I have one question for you. What epoxy formulation did you
use on that fiberglass intake manifold?
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 02:04:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifold tuning.
This nifty little chart from Bill Carroll's Mazda Rotary
Engine Manual illustrates the differences in the rate
of change of the intake volume. This is one of the
reasons that tuning technology from piston engines does not
work well with a rotary engine.
I suspect that when the rate
of change of the intake volume matches the speed of
sound the tuning effect works best. In electronics this
is called impedence matching. Or low VSWR Ed :-)
Notice the piston engine completes its volume expansion
in 180 degrees of crank rotation while the rotary takes
270 degrees of e-shaft rotation. Not only that the next
intake expansion takes place at 810 degrees in the rotary
while not until 900 degrees for the four stroke piston engine.
What happens around 540 degrees in the four stroke is
compression and expansion. This is happening in the
background in the rotary engine during this time as it
compleats all four cycles in only 360 degrees.
A true multi-tasking internal combustion engine.
Truly one of the wonders of the world!
I feel special just fooling around with these things :-)
Therefor for a given RPM things will be different with the
rotary in regard to intake tuning.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 03:12:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
Paul Yaw wrote:
Hi everybody,
I would like to point out a few things concerning intake tuning that I
think are inaccurate, and expand on a few others.
For some reason that I cannot explain, whenever I verbally disagree with
someone I tend to feel that I am being argumantative and abrasive. As a
result, I normally keep my mouth shut if I disagree with someones
opinion. Because of that weird personality quirk, I had not intended to
respond to this. Then it occured to me that I certainly wasn't doing
anyone a favor since the whole point of this mailing list is the
exchange of ideas. So here goes.
Tracy Crook wrote:
I think we must remember there are two different methods of tuning at work
here.
The tuned pipe manifold that has been the major topic of discussion on this
thread depends almost entirely on inertial effects
A "tuned pipe" refers to using the naturallly occuring organ pipe
resonance to "supercharge" the engine. Inertial supercharging is an
entirely different matter, but both methods rely on increasing the
pressure at the intake port during the period from bottom dead center to
intake port closing.(Approximately 70 degrees after bottom dead center
on a 6-port 13B) The purpose is to create a pressure differential
between the intake port, and the chamber so that the chamber will
continue to fill even though its volume is decreasing.
(once the air starts
moving in the pipe it wants to stay in motion) and the resonant frequency of
the pipe. (major simplification here) This is certainly a legitimate method
of increasing volumetric efficiency but it has certain drawbacks. One is
that the improvement works over a small range of engine speeds (and as has
been pointed out, actually hurts at others) and the pipe length is rather
long at the engine speeds we want in aircraft use.
Regardless of the length of a pipe, these pressure waves will ALWAYS
exist. However, the pressure waves will typically be stronger in a
longer pipe of the same diameter. The reason for this is that upon port
opening the mixture in the intake pipe must be accelerated to initiate
flow. A longer pipe has a greater mass of mixture to be accelerated,
and so will require more energy to do so. This results in a stronger
initial pressure drop in the chamber which is what initiates the
pressure wave in the first place. In the case where the pressure wave
is initiated by the pressure increase after intake valve closing, the
same thing applies. The greater mass of mixture results in a higher
pressure which of course initiates a stronger pressure wave. Mazda, in
their SAE paper concerning the "Dynamic Chamber" completely ignores the
effect of the initial low pressure wave initiated at intake port
opening. Using long pipes for the purpose of harnessing high amplitude
pressure waves will most certainly have the effect of lessening the
power at some speeds, and increasing it at others.
The other method (the one I designed around) is the "Dynamic Chamber"
effect as described in Kenichi Yamamoto's book. I reprinted the charts
showing how this worked at the end of my conversion manual. The full
explanation of this effect would require a much longer message than this but
if you study and understand what is going on here, you will see that it
depends on the fortuitous timing between the two rotors in the 13B. (note
that this will NOT work on a three rotor 20B due to the different timing
relationships between rotors). One really nice thing about it is that it
is a broad band effect. It works at ALL engine speeds and has none of the
"dead spots" of the tuned pipe.
The "Dynamic Chamber" effect also relies on pressure waves travelling at
the speed of sound. For this reason it will be "in tune" at some speeds
and "out of tune" at others just like the pressure waves in an
independant runner manifold. The purpose is to have the pressure waves
arrive at the intake port at the proper time. Since the speed of sound
does not increase with engine speed, this can only happen over a very
narrow rpm range. If you look at SAE paper 831010 you can see that the
engine actually had better volumetric efficiency at 3000 rpm with a
separator in the plenum which kept each rotors pressure waves separate
from each other.
snip......... More stuff from Tracy.
In last months tech. article I went into a fair amount of detail on
pressure wave tuning. As it is written, it is meant to be applied to
the exhaust system, but pressure wave theory applies to intake and
exhaust in the same manner. You can find the article at
http://personal.riverusers.com/~yawpower/jantech.html
Good explanation of tuning effects Paul.
Thanks.
BTW what is the title of SAE paper 831010?
The proof of the various theories will be discovered in the long
run with actual performance of airplanes.
I might point out we don't give a fig about how broad the torque
curve is. The chart below is from Theory of Flight the classic
book by Von Mises. Pre is power required and Pav is power avialable.
Pav is mostly a function of the propellor. A variable pitch prop
or constant RPM prop (constant max HP) would convert the Pav to
almost a horzontal line. This chart is for a fixed pitch prop.
Paul Lamar
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______________________________________________________
Date: Fri, 22 Jan 1999 09:55:33 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Displacement II???
Anderson Ed wrote:
Paul, I understand your explanation and analogy to the 2 cycle engine,
but here is my dilemma.
If I had a 80 CID 4 stroke reciprocating engine I get the theoretical
airflow by:
(CID/2)xRPM/1728
(80/2)X6000/1728= 138 CFM airflow
If I had the same displacement for a 80 CID 2 cycle I get the
theoretical airflow by:
CID*rpm/1728= CFM
80*6000/1728 =277 CFM airflow or double that of the 4 stroke.
Now if I take the rotary and treat it like the two stroke I get
CID*rpm/1728 = 80*6000/1728= 277 CFM
which does agree with and certainly substantiates your viewpoint of
treating it as a two stroke.
I was just trying to get the airflow value based on the physical
displacement dimensions and rate of displacement. Because I know the
$%#@ rotors are only rotating at 2000 rpm with the shaft at 6000 rpm. It
is the rotors that displace the air, so how do I get 277 CFM out of 80
CID of rotors spinning 2000 rpm??. Because if I go:
80X2000/1728= 92 CFM which clearly is less than 277CFM. Now if I make
the assertion that each chamber volume is swept three times during one
rotor revolution then I have:
(80x3)x2000/1728=277 CFM which agrees with the value arrived at using
the 2 stroke analogy. Now I have no basis for asserting that my
calculations should threat the chamber as having being swept 3 times
during one revolution, except to treat the chamber with 3 flat areas as
as three cylinder in a reciprocating engine with three pistons.
Right in here somewhere must be the problem. The rotor does indeed
Rotate at 1/3 e-shaft speed.
But it not only rotates.... a spot on the face of the rotor
moves away from the intake port while enlargeing its volume at a
greater rate than it would if it merely rotated. As the chart shows
it does this in 1/3 of 270 degrees or 90 degrees of ROTOR rotation.
Never-the-less there should be no 1/3 factor in your calculations.
Forget the rotor rotation. Just remember it gulps one displacement's
worth of air in one e-shaft revolution just like a two cycle.
Here is the chart again in case you missed it. capchang.jpg
Also take another look at the animation on the Source for tip
seal site (Hurley engineering). Paul
So if I consider a 2 cycle, 6 cylinder (two chambers x 3 faces) engine
with each cylinder having 40 CID (one chamber), then I get
(40x6)x2000/1728= 277 CFM which again agrees with your analogy and
"justifies/Validates???-maybe" my assertion of the rotor chamber being
swept 3 times during a revolution as a valid concept. I any case, that
is my only basis for the way I calculated the airflow displacement.
Perhaps, it really does not matter, but I just have always had this need
to understand what was factors in such equations and results.
Yes, I can use 80 CID x 6000 RPM/1728 = 277 CFM, its simple and gives
the correct answer, but that did not concide with my understanding of
the physical reality of two rotors spinning at 2000 rpm.
Sorry to bore you with my unwillingness to let go of this bone, but I
think this has exhausted its entertaiment value.
Appreciate your input as it did help me to better understand the 2 cycle
anlogy.
Ed Anderson
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______________________________________________________
Date: Fri, 22 Jan 1999 10:11:41 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
CC: Klaus Savier <lse@west.net>
Subject: Highest temp epoxy for intake manifold.]
Here you go folks 330 degree F epoxy.
Hunter GA (Gary) at MSXSCC wrote:
Paul wrote:
Do you have any recommendations for a high temp epoxy
that would work on an intake manifold. Hand lay up
over carved blue styrofoam.... possible low temp oven cure
after initial room temp cure.
Dear Paul Lamar
Yes, I suggest EPON Resin 862 cured with a chemical compound called
diaminocyclohexane, a.k.a. DCH or DCH-99. Both are available in quart
and possibly pint quantities from Miller Stephenson Chemical Co. in Danbury,
CT. 1-800-992-2424. '
The mix ratio is 17 / 100 by weight, i.e., 17 parts DCH per 100 parts EPON
862. Be accurate, use a digital scale if you have one. If not, check out
http://www.balances.com/index.html and shop for something with at least 1
gram accuracy. I have this model here -
http://www.balances.com/gs2001.html or look at the Ohaus LS2000
http://www.balances.com/ls.html.
Word of caution, when you receive the resin. It most probably will be
crystallized - do not use it in that condition. You know the drill.
Submerge the sealed can of resin in a bucket of hot tap water. Replenish
the hot water from time to time to reheat it. After about 2 hrs. or so, the
resin should be fully reconstituted to a liquid state. Allow to cool to RT
before using.
DCH is a pretty powerful corrosive with a rather strong ammonia smell.
Keep it off of you, don't sniff the container and wear gloves. It will have
a gel time in a 100 gram mass of about 50-60 minutes. In a laminate it
will take longer. Do not use it below 70F. Preferably 75F. After the
lay-up has cured a day or so, you can begin to post cure it. Start out at
about 120F gradually increasing to 170F-180F over period of a couple hrs.
Finally, hold the temperature at 180F for 16 hrs. Allow to cool slowly in
the oven.
The cured product will have a glass transition temperature between 300 and
330F.
Any questions, call me 1-800-832-3766
Gary
--
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______________________________________________________
Date: Fri, 22 Jan 1999 10:16:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil Temp
Tracy Crook wrote:
snip........
BTW, Do you know what the difference is on your engine Ed (Anderson)?
Tracy Crook rws@altavista.net
Anderson Ed wrote:
No Tracy, I don't. I only have an oil temp sensor after the oil
cooler. However, I have several unused fitting on the bottom of my oil
pan, it would probably not be very hard to screw in an oil temp sensor,
but it would be measuring temp of oil at the bottom of the pan. Don't
know how well that would represent oil temp out of the rotors.
Ed Anderson--
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______________________________________________________
Date: Fri, 22 Jan 1999 10:21:17 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifolds
Anderson Ed wrote:
Hi Paul Yaw,
Don't know enough to comment on the aiflow theory, but find it all very
interesting. However, I can comment on your comment about feeling like
you may be coming across abrasive. I don't read you that way on the net
and I personally don't think I can recall a time when I felt anyone of
the net was out of line. Sometimes strong views are held and defended,
but what the heck if someone is the Miltoast type they won't be on
this net talking about what interest us anyhow.
Keep it up, I think when we get two viewpoints discussed we all gain a
better understanding.
Ed Anderson
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______________________________________________________
Date: Fri, 22 Jan 1999 10:19:20 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Modifying the ports on a six port engine.
Paul wrote:
Finn Lassen wrote:
Ed, did you (or the guy who did the porting for you) smooth out the sharp
corner/end of the torque tube openings/tunnels?
Unlike Tracy, I actually removed the tubes, and poured JB-weld down there at
at 45 degree angle for a relatively smooth transition.
Finn
Anderson Ed wrote:
Finn,
I really don't know. The motor was overhauled and ported by Jay of
Tuscon, I belive Paul YaW may or may not have done flow work for Jay. I was
told the guy doing the porting really knew his stuff, so hopefully he
smoothed any sharp corners, but I don't really know. There does not
appear to be any expoxy filler in the tube holes.
Ed
--
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______________________________________________________
Date: Fri, 22 Jan 1999 10:49:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Composite intake manifold. Epoxy temp.
Bob and Marnie Falkiner wrote:
I made a light weight fuel fill pipe with safety poxy ( a hexel brand resin
i believe) but any of the common 2 component bis-phenol type resins should
be more than adequate. many of these are used for coating the bottom of
large fuel storage tanks, for example and can be post cured for good high
temperature performance. Don't go too high as it gets increasingly
"brittle" and more prone to cracking/crazing at lower temperatures. I
wrapped the blue core in a heavy polyethylene (i think i used vapour
barrier) and this gives a very smooth internal surface, and is easy to
remove after the blue foam is dug or dissolved out. cut it in long strips
about the same diameter of the tube, and it comes off easily later in long
strips (the epoxy will not stick to it). If you don't do this you will end
up with a very rough surface like a course sand casting, which i suspect
would give bigger flow losses in an intake manifold. you could use a piece
of 1/4" phenolic flat plate as the attachment point to the head as it has
very good heat resistance, and could limit the heat transfer further with a
thick gasket.
I've thought about doing this for the Revmaster in the past, as you could
get rid of about 20 pounds of ugly steel and shitty carburetors.
Good to hear from you Bob. Bob and I go back at least five years
or more back to the days of Genie before the Internet got to be
the only thing in the world. Auto piston engines and why you sould not
fly with them was the hot topic.
Bob is a chemical engineer working for Exxon last I heard.
Excellent tip on how to part the foam from the epoxy. I also
like the phenolic plate idea as it is a very high temp plastic.
See a prior post on the recommendations of Shell for a higher temp
epoxy.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 11:06:30 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct
Jeff Spitzer wrote:
There's no question that the P51 installation was exceptional and right.
My point was that things like that don't just "scale" to a different A/C.
Only the design intent scales.
Jeff Spitzer
Why not Jeff? Airfoils scale within the constraints of the reynolds
numbers. The boundry layer thickness percentages might be slightly
higher. It is not as if I am going to one tenth the size. Just half.
It probably won't be perfect but it should be ten times better than what
most people are doing with their cooling systems.
If nothing else it is an excellent atarting point.
Hopefully I can convince someone like Dave Lednicer to to a computer
refinement of the design for our purposes.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 11:10:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Coordinates on P51 duct
Bktrub@aol.com wrote:
There you guys go again, stealing a design from nature. Fishes gills work on
the same principal- the capillaries in the gills run opposite the flow of
water against them, so the least oxygenated blood, which has the greatest
affinity for O2, hence the greatest ability to scavange O2, is exposed to the
water just before it leaves the gill. The blood which is already partially
oxygenated is exposed to the freshest and most oxygenated water, and therefore
has a tendency to pick up more O2 out of the water.
I've been intending to put a P-51 type scoop under the belly of my RV-4 for
the cooling, using the bulkhead under the passenger seat for the mount for the
cooling elements. The scoop will be aproximately 26 inches long prior to the
radiator(s) and aproximately that long after the rads.The scoop opening will
be around 16" by 3" tall, 2" out from the skin of the aircraft. The rads can
be 26" wide by 8" tall, and thickness to be determined. A cooling flap is
incorporated. I can get you a sketch as soon as I get access to my brother's
scanner.
The construction of the fuselage starts soon. The intent is to use a 4 port 13b
with fuel injection, hopefully making ~ 160 HP.
The idea of trying to manage to design an effective cooling system AND fit it
into the engine cowling is too intimidating for me. I feel that in the long
run, it will be easier to start with a clean slate. The benefits are -
straight airflow in and out, with no direction change, simple design, and
flexiblity as far as cooling elements go. I still don't know how to
incorporate the oil cooling into the design. Use a heat exchanger, have a
separate cooler elswhere, sandwitch an oil cooler between two radiators?
Any Ideas?
You are doing the right thing! You will be rewarded with an exceptionally
fast airplane.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 14:15:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct
Jeff Spitzer wrote:
I know it sucks and what you are saying is essentially true. But the devil
is in the details. Someone who is not fully aware of what they are doing
can screw it up when they think they are just scaling. It has to do with
3-d vs 2-d flow affects if you scale the width different from the cross
section for instance, another thing that comes to mind that is much more
difficult to predict is the effect of the back pressure of the radiator
core(s) (and the combined effect of oil and water coolers) on allowable
diffusion rates. Even modeling this is difficult because you need good
heat exchanger flow coefficients. The duct can be much more aggressive (in
area increase) immediately before the HX due to the natural back pressure
effects of the core. This is slightly different for different cores. I'm
not aware of how much this effect was used in the P51 duct but I expect it
was. My point was not to be taken as "using the P51 stuff is a waste of
time" my point was supposed to be "the engineering behind the P51 duct is
much more useful in the real world than the full scale coordinates". The
engineering behind the P51 installation is very well understood (by some
good engineers) today although it was outstanding for its time 55 years
ago. The difficult part is passing on that info to the homebuilder.
Jeff Spitzer
I wish we had the capability. In the mean time it is better than nothing
which is what we had before we had these 2D coordinates..
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 14:21:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Displacement??
Anderson Ed wrote:
Ok Gents,
I saw Paul Yaw's reply as well as others and appreciate the information
about precise specs of the rotor. At the risk of becoming a bore on the
topic, and beginning to feel pretty stupid about this thing, I have one
last question concerning calculating airflow.
I understand that the equation 80CIDxRPM/1728 does give the airflow for
the 13B. My problem is I know at 6000 rpm of the Eccentric shaft, the
rotors are actually revolving at 2000 rpm. Now I know I have been told
to forget that relationship as I don't need to understand in order to
calculate the airflow using the above equation.
My problem is I just can't let it go for the following reason:
If the rotors have 80CID and THEY are actually physically revolving at
2000 rpm (Eccentric shaft at 6000 rpm) and displacing 80 CID each
revolution I don't get 277 CFM, I get 92 CFM.
The only way I can get the physical constraints to give me 277CFM at
2000 rpm ROTOR is to assume that each face of the rotor sweeps the full
volume of the chamber during one revolution. To wit:
40(CID/Rotor)*2(number rotors)*3(number faces sweeping the volume of 40
CID in one revolution)*2000 (rpm of the rotors or 6000/3 of the
eccentric shaft)/1728 = 277 CFM. The only unverified assumption that I
believe I make (and it indeed may be incorrect) is the the chamber
volume is swept by each of the three faces of the rotor during one
rotation. I don't have confidence in my assumption, but it is the only
rationale that I could come up for rotors spinning 2000 rpm to give 277
CFM.
Now perhaps there is some physical aspect of the rotor (or airflow) I
don't know about or understand. But simply telling me to use
80xrpm/1728 to get 277CFM at 6000 eccentric shaft rpm, while it provides
the correct answer, does not convey to me how the rotors actually
spinning at 2000 rpm with 80 CID produce 277 CFM.
Again, my apologies to those who understand the mysteries of the 13B.
In any case, this is the last time I will raise the topic as it has
occupied enough bandwidth{:>}(paul).
Ed Anderson
RotaryEngineAnimation.gif
BTW people I have updated the web site with the thread on composite
intake manifolds (and other things) as an experiment. Let me know
if you think this is a good idea.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 19:49:13 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Displacement??
Brent Regan wrote:
Ed,
Each lobe of the rotor displaces 40 cubic inches. There are three
lobes on the rotor. Each rotor rotation displaces 120 cubic inches NOT
40. If you insist on using 40 cubic inches and 2000 RPM then you need
to multiply by 6 lobes (three lobes per each of two rotors).
Brent
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______________________________________________________
Date: Fri, 22 Jan 1999 19:52:58 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: one-rotor
Byron Brandon Ward wrote:
Paul,
Do you know if anyone is using the one-rotor from the link on your web
site (www.onerotor.com) and if so how successful or unsuccessful it was?
Thanks,
Byron Ward
<wardb@umich.edu>
I don't know of any. It's running on NG so the power might not
be what you need. It would also be too expensive. I would just try to
buy a one rotor shaft and counter weights from them and not
a whole engine.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 10:59:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Intake manifold tuning.
Karl Szczypta wrote:
Paul,
Since the rotary has a longer expansion time within that
cycle wouldn't that make it more efficient over a piston
engine? If so why is the BSFC a wee bit higher?
Karl
In a word, heat loss to the combustion chamber walls which
results in incomplete burning of the fuel which results
in higher exhaust gas temperature. That is why turbo's
work so well on rotaries.
This of course is greatly over simplified. Did you get my book
list I uploaded about a month ago?
I got to figure out how to get text on the web site with
a link to it. Anybody have any suggestions after taking
a look at my web site HTML file?
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 22:44:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Interesting book
facilitator1@juno.com wrote:
Read Speed with Economy by Kent Paser.
Price of book 24.95+3.50 shipping
5672 West Chestnut Ave Littleton Colorado 80123
Check "CYCLONE " Headers at local speed shop, prevents hot exaust gasses
from flowing backwards into the combustion chamber.
Also check out exaust Jet THRUST Nozzle effect.
Vaporized fuel needs turbulance to stay in vapor state,
sharp corners after carb do that.
Enjoy book ! Some will not apply to rotary. Will apply to a/c.
Virg
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______________________________________________________
Date: Fri, 22 Jan 1999 22:46:14 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: one-rotor
Byron Brandon Ward wrote:
Do you know if anyone is using the one-rotor from the link on your web
site (www.onerotor.com) and if so how successful or unsuccessful it was?
I don't know of any. It's running on NG so the power might not
be what you need. It would also be too expensive. I would just try to
buy a one rotor shaft and counter weights from them and not
a whole engine.
From looking at the web site it appears that they offer gas engines as
well. Do you know how extensively modified the engine is from stock? i.e.
could you buy just the shaft as you say and build the rest of the engine
yourself. BTW I don't feel that the price is that unreasonable. A
converted VW would cost about the same (if you didn't do it yourself).
Then again quite a bit of modification of their engine may be required to
convert it to aircraft use.
Byron
I would build my own.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 22:54:23 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Six port verses four port engines & tuning.
Paul Yaw wrote:
Anyone searching for VE above 100% should start by selling their 6-port
engine. The easiest way to achieve this is with a peripheral port
engine. A PP engine has far superior intake port airflow, you can
easily mate a real manifold to it, and it has overlap, which is
essential when the goal is high VE. A poor motor cannot simply be
"tuned" to achieve a VE above 100%. Pulse tuning is quite helpful, but
it is no cure all. If the airflow potential is not there, all the pulse
tuning in the world is not going to turn it in to a fire breathing
beast..
Paul, I would like to see some dyno test of various tuned manifolds
at 6000 RPM. If you want to really get trick try to combine
max power at 6000 RPM and low BSFC at 4500 to 5000 RPM for
cruise economy.
I do not have any dyno results for a 13B with a custom built manifold.
If a customer is willing to spend the money for a custom manifold, and
extensive dyno tuning, a six port is out of the question. This kind of
custom work will show MUCH better results with either the old four port
housings, or later turbo four port housings. The six port housings have
horrible airflow numbers, and a set of extensively worked intake ports
will still flow much less than even a poorly ported four port housing.
I am not trying to discourage anyone, but I want everyone to understand
that if high VE is the primary goal, the six port engine should not even
be a consideration. As for BSFC, it is normally best at the engines
torque peak. The foremost consideration when trying to place the torque
peak is inlet, and exhaust velocity, and port timing. As for
appropriate tuned lengths, it will vary from engine to engine, but for
the most part it will be determined by port timing, and what rpm range
you would like to optimize. I do have a few dyno files here at home. I
will try to dig something up that might be interesting.
Oh, I almost forgot, the title of SAE paper #831010 is "Improvement of
Rotary Engine Performance by New Induction System"
Jeff Spitzer-You mentioned 130% VE for one of the Moller engines. Do
you know what the horsepower output was? If so, at what rpm?
Paul Yaw
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______________________________________________________
Date: Sat, 23 Jan 1999 09:33:26 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: dyno run
Paul Yaw wrote:
Hey Paul,
I dug up the only dyno run I could find for a low rpm engine. This is a
12A with a mild bridge port, 34" long 1 5/8 id headers, collected to a
single piece of 3" tubing 16" long, with a highly modified stock
carburetor, and a ported stock manifold with a plenum (Dynamic Chamber
in Mazda terminology)
The intent of this engine was to build peak
horsepower at 6500 rpm. The headers were built with a slip joint so
that the length could be adjusted on the dyno. Several 3/4" lexan
spacers were made for the manifold so that its length could be
adjusted. If I remember correctly, the runner length of the secondaries
ended up being about 18", and the primaries are shorter, but I cannot
remember by how much.
If you look at the info in the top right hand
corner of the screen, you will see that the air fuel ratio was extremely
rich. The carburetor had been converted to annular discharge (no
booster venturis) and the atomization was horrible. For this reason,
the engine made the best power with a very rich mixture. (Much of the
fuel was unburned, and simply passed into the exhaust. I understand
that this does not directly relate to an aircraft application, but since
you asked, I wanted to show something that was designed to make power at
relatively low rpm levels. (For a rotary anyway!) This will at least
give everyone an idea how much air is required to make this kind of
horsepower. The intake and exhaust lengths may also be appropriate, but
only as a starting point. Sorry I don't have anything for a low rpm
6-port.
Paul Yaw
Paul, I think you forgot to attach the "screen".
What info? Is there some graphics that go along with this?
We can handle .gif's and .jpg's.
Or FAX me something at (310) 475 5517.
Paul Lamar
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______________________________________________________
Date: Sat, 23 Jan 1999 09:48:30 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Six port verses four port engines & tuning.
Pebvjs@aol.com wrote:
When you say 6 port engine do you mean 4 intake + 2 exhaust, or six intake
ports?
Is a 4 port 2 peripheral intake + 2 exhaust ports?
Ed pebvjs@aol.com
So far all Mazda 13B and 12A engines have only two peripheral
exhaust ports. Some 13B engines had six intakes and some only four.
One on each side of each rotor for the four port.
Two extra ones at the very front and rear of the engine
for the six port engines. The diameter of these four ports
at front and rear is only about one inch.
The four port 12A engines have oval ports that are about one
inch wide and an inch and a half tall.
A street porting job entails enlarging and smoothing these
dimensions by useing a small air powered die grinder.
The peripheral intakes were only used in racing. Peripheral
intake rotor housings can be bought from Racing Beat and the Mazda
racing department.
Click on the News Letter web site below for a link to the Racing
Beat web site.
Paul
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______________________________________________________
Date: Sat, 23 Jan 1999 10:04:40 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Tracy Crook wrote:
Paul Yaw wrote:
The "Dynamic Chamber" effect also relies on pressure waves travelling at
the speed of sound. For this reason it will be "in tune" at some speeds
and "out of tune" at others just like the pressure waves in an
independant runner manifold. The purpose is to have the pressure waves
arrive at the intake port at the proper time. Since the speed of sound
does not increase with engine speed, this can only happen over a very
narrow rpm range. If you look at SAE paper 831010 you can see that the
engine actually had better volumetric efficiency at 3000 rpm with a
separator in the plenum which kept each rotors pressure waves separate
from each other.
When I made the comment about about " staying out of this one" it had
nothing to do with concern about being argumentative. It was a matter of
time. I really enjoy a spirited technical debate or Socratic dialog but
they can really eat up some serious hours. I followed one debate on
CompuServe's avsig forum (composite Vs aluminum design) that went on for
months. I got a great education just following it so don't hold back Paul
(Yaw)! There are no tender toes here.
To respond to your reply, I agree about the function of tuned pipes /
inertial tuning etc. I freely admitted that I greatly simplified the
explanation. My main point was that there was a significant difference
between them and the "Dynamic Chamber" (DC) technique developed by Mazda.
Just because they both use pressure waves does not mean they are the same.
The DC function does not primarily rely on a tuned length but rather the
fact that one rotor happens to close its intake port and enter the exhaust /
intake overlap period (which is the source of the pressure wave in this
case) during the last portion of the other rotors intake stroke. This would
happen even if the runner length were zero. I am not saying that zero is
the best runner length because as I stated before, even a DC manifold can
take advantage of inertial tuning as well.
The significance is that it is a lot easier to design a compact DC manifold
for aircraft use than to find room for 31 inch tuned pipes.
I don't even know the name of the SAE paper you cited so I can't say if we
are comparing apples to apples or not. As evidence that the DC design works
over all engine speeds, I attach the dyno chart from Yamamoto's book
comparing standard and new (dynamic chamber) manifolds on a 13B. note that
the DC design had higher torque at all engine speeds.
SAE paper #831010 is "Improvement of Rotary Engine Performance by
New Induction System"
Paul Lamar,
Thanks for digging up those diagrams on the 88 / 89 induction systems.
Yes, the High & Low speed captions are reversed.
The composite manifold I am testing was built by the Glasair flyer using the
same epoxy as on the plane. (not especially high temp stuff). It bolts to
the stock lower manifold, not directly to block so temperature will not be a
problem. The hottest it will get will be at engine shutdown when the engine
heat collects in the cowl.
Tracy Crook rws@altavista.net
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It seems altavista does not transmitt gif images Tracy. We did not
get this image at all let alone in a form which we can save.
Try FAXing me at (310) 475 5571. Do it real early in the morning
in FL (3 hr earlier) as my fax line and modem line are one and the same.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 10:12:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Steve Parkman and one-rotor
Lonnie Wood wrote:
Byron Brandon Ward wrote:
Paul,
Do you know if anyone is using the one-rotor from the link on your web
site (www.onerotor.com) and if so how successful or unsuccessful it was?
Thanks,
Byron Ward
<wardb@umich.edu>
Bryon,
I talked to Steve Parkman over a year ago. He said he had a customer
that had a one rotor running with his computer system. I do not know what
plane it was going on. Steve had a partner that might know something about
it. I checked their web site last week and it was still up and running at
www.flash.net/~swagaero/
Lonnie
rwood@iceinternet.com
Well Gerry Hess has one but he did not get it from onerotor.com.
Gerry Hess <GVH@yellowknife.com>
As I recall Paul Yaw mentioned he knew who owned the Parkman
web site one rotor.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 10:45:38 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Year Models 13B suitable for AC use.
David Munday wrote:
On Wed, 20 Jan 1999 13:57:30 -0800, Paul wrote:
Did you see the link on our NL web site on the subject Dave?
I assume you mean "13BT vs. 13B-REW" That's a great article on one
change in the Turbo between 88 and 89. The article implies there was
a change after 91, unless I misread it.
Tracy said: "it should be 1986 or later to get many of the
improvements Mazda incorporated (like the 12 pin rotor gears etc)," so
there was a big change between 85 and 86.
So There was a big break 85-86 and another 88-89 and a third 91-92.
What was the change in 91-92?
David Munday - mundayde@muohio.noise.edu
Webpage: http://www.nku.edu/~munday
PP-ASEL - Tandem Flybaby Builder - EAA-284 (Waynesville, OH)
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 11:21:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: one-rotor
Gerry Hess wrote:
Hello Byron;
I am the proud owner of a single rotor Mazda engine and I agree with Paul Lamar.
Build your own. These people are not admitting to using any Mazda componants
when the pictures show an obvious Mazda engine, and I believe in giving
credit where it is due. The manifold is cause for laughter, and the
statement ---'Our Patent Pending "Eccentric Shaft Technology ' will probably
piss off Felix Wankel, as the technology and info on making eccentric shafts
has been available for years. NASA built single rotors and published the
data and engineering drawings in the 80's. I think it is still on their web
site. So.. if you want to fly with a good pump engine and buy your Mazda
parts from onerotor, have fun. This forum is a gold mine of information and
can help us all build better and fly safer, and the help is definitely out
there if you build your own.
Gerry
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______________________________________________________
Date: Sat, 23 Jan 1999 11:22:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Design
Marc Pedings wrote:
Paul Lamar wrote:
It is remarkable what Morse is claiming.
It would be interesting to call them and ask them about
the difference.
Paul Lamar
I have a few tidbitz of information about the morse chains as well as an
engineering application from THEM. It includes: Life, chain sizes,
pitch, design ramifications, etc. I also included Gates Poly Chain data
for comparison.
I have moderate application experience (at work) with HyVo and have been
working on a PSRU drive in CAD and on the bench. I attached a file that
will give you a start! Go check out most any front wheel drive
transmission and a 4wd transfer cases. HyVo is the choice for these
applications.
Marc
As Bill Freeman and I pointed out Marc. The max continuous HP any
pickup truck is likely to see is 100 HP. Sport Utes even less.
That is total so a four wheel drive transfer case would be half that
or 50 HP.
Go ahead and build one but keep checking the prop back-lash.
BTW I got the zip file. It appears to be Windows 95/98 long file names.
Can you shorten them to no longer than eight characters with a
three character extension. Or change the first letter in each file
name to a unique character. I don't have pkunzip for Windows 95/98.
Or convert the text to plain ASCII text or HTML and send that.
Or convert the graphics to gif's and jpg's (the Internet standards.)
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 11:29:37 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds & turbo 13B's
Phil Williamson wrote:
What is the importance of a tuned intake on a turbocharged rotary? Can one get
away with short (er) runners to save space?
Should work more or less the same. Mazda felt it was important enough to
include it. The worlds most powerful 13B turbo engine (730HP) owned
bu Abel Ibarra also uses it.
I sorta like the idea of direct drive , which is why I'm thinking about
turbocharging. What does a decent turbo system cost compared to a PSRU. What about
weight?
Phil
About $2500 I would guess. Another $1200 if you use ceramic apex
seals. About the same weight as a PSRU. Don't forget to install
a large intercooler.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 12:00:14 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Design
The MORSE HV Chain system HP as follows. The Maximum HP is
dependent on the smallest sprocket.
I will publish my detailed engineering analysis in CAD when I
complete it. This is just for information purposes only.
The 1/2" pitch was recommended to handle the higher 5400 RPM
and still give reasonable HP ratings. 3/8 pitch is not strong enough
and 3/4" pitch isn't rated to a high enough RPM.
I will have my page up soon with my progress & drawings. ENJOY!!!
Marc Pedings
marc@juno.com (AIRSIG & public drop box)
marc@airnet.net (regular private mail)
1188797 ICQ
1/2" pitch, HP Per 1 inch of width verses RPM
Teeth 1500 1800 2100 2400 2700 3000 3600
19 47 56 65 74 83 91 107
21 52 62 72 82 91 100 117
23 57 68 78 89 99 108 126
39 94 110 125 139 151 161
41 98 115 130 144 156 165
43 102 119 135 149 160 169
Teeth 4200 4800 5400 6000 6600
19 122 136 148 159 167
21 133 146 158 167 174
23 142 155 166 174 178
1/2" Pitch Chain Weights per foot length
Size Weight Average Ultimate Tensile Strength in Pounds
1" 1.15 10,000
1.5" 1.73 15,000
2" 2.3 20,000
3" 4.6 30,000
Weights of sprockets all 1/2 inch pitch.
specific bore sizes must be ordered.
Teeth Weight (approx. in LB)
19 2.5 1" Face Width
21 3.3
23 4.0
38 16.1
42 20.2
19 3.3 1 1/2" Face Width
21 4.3
23 5.1
38 19.7
42 24.6
19 4.1 2" Face Width
21 5.2
23 6.3
38 20.1
42 25.1
19 5.3 3" Face Width
21 6.9
23 8.6
38 27.2
42 33.9
It occcurs to me this data could be for automotive
low duty cycle use which would explain the descrepancy
with the MEHB data.
You might want to double the width just in case.
I would use a three inch width to be conservative.
That is not going to add that much weight or cost.
If it proved to be over designed in the flying
prototype you could always reduce it later to save
a little weight.
Keep checking the back-lash in the prototype.
If it does not increase rapidly you are home free.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 16:48:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Inherent balance of multi-rotor stacking?
Dale Smith wrote:
Forgive the ignorance ... I am an old turbine driver, but very new to
the Wankel engine and it's "wobbling balance"on an eccentric. It is
my understanding that in a piston engine, the inherent balance is very
much a factor of cylinder number and placement i.e. Inline 4, V-6,
V-8, even dual bank 18 cylinder "big round" motors (with appropriate
firing sequences).
My question is: Does the addition of more rotors, 3 or 4 (or more)
ever reach a "natural point of balance" such as V-8s and V-12s do. I
know in the V-6 is impossible to achieve balance without offset
cranks, trick counterweights, etc. (just a function of it's V-6
design).
Is there a Wankel "sweet number"? With a corresponding firing
sequence i.e. 1-3-2 or 1-4-2-3 ?
I seem to remember NASA doing a lot of work with the Wankel that was
showcased at OSH in the early 1980's. Theirs was a Diesel design, if
I recall. Anybody have line on this research? Should be in the
public domain. Thanks, Dale Smith
Unlike a piston engine they are all in total balance.
The only thing that varies is the number of torque pulses.
One pulse per rotor, per rev.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 16:54:02 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 12A dyno run
Paul Yaw wrote:
Oops! Here it is as a .gif
Paul Yaw
Not bad for a carburated 12A rotor motor. We should be able to get
at least 10 or twenty more HP out of an EFI 13B.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 17:06:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Paul Yaw wrote:
Tracy Crook wrote:
To respond to your reply, I agree about the function of tuned pipes /
inertial tuning etc. I freely admitted that I greatly simplified the
explanation. My main point was that there was a significant difference
between them and the "Dynamic Chamber" (DC) technique developed by Mazda.
Just because they both use pressure waves does not mean they are the same.
It is just another way of using these pressure waves which exist in all
manifolds.
The DC function does not primarily rely on a tuned length but rather the
fact that one rotor happens to close its intake port and enter the exhaust /
intake overlap period (which is the source of the pressure wave in this
case) during the last portion of the other rotors intake stroke. This would
happen even if the runner length were zero. I am not saying that zero is
the best runner length because as I stated before, even a DC manifold can
take advantage of inertial tuning as well.
This pressure rise in the manifold will create a pressure wave which
will travel in any direction that the intake tubing allows. In this
case, this high pressure wave must reach the other rotor approximately
110 degrees later to be effective. In other words, the intake closing
of rotor number two actually occurs about 110 degrees after the overlap
period, (and corresponding pressure spike). Since 110 degrees is
equivalent to a given amount of time, based on engine rpm, the purpose
is to provide an appropriate distance between the two ports to delay the
wave by this amount. Rather than looking at this as a "tuning" effect,
It might be easier to simply think of it as a delay. Lengthening the
runners will result in a longer delay, or a greater amount of time
before the pressure wave from one rotor reaches the other. This will
make the arrival of the pressure wave appropriate for a lower rpm. I
think the confusion may be based on the assumption that the pressure
rise at the intake port caused by the spike of exhaust gasses
pressurizes the ENTIRE manifold. This is NOT the case, as doing so
would require a substantial amount of flow. In other words, for the
pressure rise caused by the exhaust backflow to pressurize the ENTIRE
manifold, a substantial amount of exhaust gasses would have to flow into
the manifold, which of course would not help power output at all. So in
fact the beneficial high presure is simply in the form of a very brief
pressure wave. I would also like to point out that the pressure spike
caused by the momentary blast of exhaust gasses is much weaker with an
open exhaust system. The 6-port engine in its stock form is mated to a
cast iron manifold with several catalytic converters, and a restrictive
muffler. At high speeds, the exhaust backpressure measured in the
exhaust manifold averages about 5psi. A proper exhaust system will have
much less backpressure, and in some cases the exhaust induced "spike"
will disappear completely. Now having said all of that which seems
quite contrary to your current designs, I feel that using a plenum is
quite effective, and feel that your manifold designs should work quite
well. As for independant runner setups, there are many different tuned
lengths that will work for a given rpm range. This is true for the
exhaust system as well. As an example, a race engine will normally show
simmilar results with 24", or 96" primary header tubes. The same is
true of the intake system. I do not currently have equiptment to
measure pressure waves in the exhaust system, but I have measured them
in the intake, and there are actually a whole series of pressure waves
bouncing around and many different manifold combinations will give
similar results for a given rpm. On thing that Mazda didn't mention in
their paperwork is a Helmholtz resonance. This is very complex, and
nearly impossible to quantify mathematically, but it does exist, and
this phenomena has been the topic of several SAE papers. Essentially a
helmholtz resonance is what occurs when you blow across the top of a
bottle, and hear a note. A resonant circuit is the result of the air in
the bottle, which is the spring, and the weight of the air in the neck
which is the mass that is resonating. These correspond to the "Dynamic
Chamber", and the runners. If you fill the bottle partially with water,
you have increased the spring rate which will result in a higher
resonance or note. Increasing the mass of air in the neck will lower
the resonant frequency, and so lower the note. I am only pointing this
out to make it clear that resonant tuning is quite complex, and best
arrived at by cut and try testing. I would love to see you make your
next manifold with adjustable length so that the optimum length could be
arrived at. The end result would be something that other people could
mimic with the assurance that it would be right for their application.
Assuming of course that they had the same engine and exhaust system.
What would be ideal is if someone would agree to reproduce a given
design, which could be optimized on the dyno. Any takers?
The significance is that it is a lot easier to design a compact DC manifold
for aircraft use than to find room for 31 inch tuned pipes.
I feel that similar, if not better results could be achieved with an
independant runner manifold, and that this could be accomplished with
reasonable lengths. The reason is that the plenum chamber has the
affect of lessening the amplitude of these waves. The waves would be
much stronger in an independant runner manifold. Of course that
requires complex throttle bodies, and so for the sake of practicality, a
plenum chamber seems most appropriate. If you would like to tackle the
project of designing a scratch built manifold that is optimized for
aircraft use, I would gladly help with flow testing, and the lengths
could be arrived at on the dyno. If you then wanted to produce these
pieces, it would make life easy for everyone else, AND you could make
some money selling them. I would like to stress again though that the
biggest improvements will come from designing something that will FLOW.
This in combination with proper tuned lengths would work MUCH better
than the current setups. I suspect that this would make the kind of
power that everyone is looking for regardless of the VE.
snip....
The reason for the improvement at ALL engine speeds is the variable port
timing. Mazda made a big deal out of a simple plenum chamber. Once
again, the DC setup IS utilizing pressure waves, and so it is rpm
dependant. The absolute best power boost from pressure wave tuning will
occur with an independant runner manifold. A plenum in fact is simply
the easiest way to feed several runners from a single throttle body
assembly.
The composite manifold I am testing was built by the Glasair flyer using the
same epoxy as on the plane. (not especially high temp stuff). It bolts to
the stock lower manifold, not directly to block so temperature will not be a
problem. The hottest it will get will be at engine shutdown when the engine
heat collects in the cowl.
Tracy Crook rws@altavista.net
I would like to point out that the lower manifold half is where the
majority of the airflow restriction occurs. When I flow test these
pieces, I first flow the ports themselves. This gives me a baseline
number. I then add the rest of the induction system piece by piece, and
record the airflow numbers as I go. The biggest whammie occurs when the
lower manifold half is bolted up. Nasty piece!
Paul Yaw
We can debate this till we are blue in the face. I want to see some
actual results both ways. Tracy needs a dyno. Tracy please borrow that
Glasair manifold and Fed Ex it to Paul Yaw for testing :-)
Paul
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______________________________________________________
Date: Sat, 23 Jan 1999 17:07:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Steve Parkman and one-rotor
Paul Yaw wrote:
Sorry, I don't know anything about the Parkman one rotor. Myself,
Chris Ross, and Gerry Hess built Gerry's one rotor. Maybe we should
call it the 6.5B? Ha ha! By the way, the one rotor site is worth
looking at from an educational viewpoint. Study that manifold VERY
closely, and then make sure you never build anything like that
yourself. That is a fine example of what not to do.
Paul Yaw
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______________________________________________________
Date: Sat, 23 Jan 1999 17:15:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: one-rotor
Byron Brandon Ward wrote:
Gerry Hess wrote:
I am the proud owner of a single rotor Mazda engine and
I agree with Paul Lamar.
Build your own. These people are not admitting to using any Mazda componants
when the pictures show an obvious Mazda engine, and I believe in giving
credit where it is due.
They do admit to using Mazda parts if you look closely
parts from onerotor, have fun. This forum is a gold mine of information and
can help us all build better and fly safer, and the help is definitely out
there if you build your own.
I agree. The main reservation I have in building my own is that my
knowledge of engines in general and rotaries in paricular is pretty
limited.
Byron
Jump right in there Byron. Just make sure it has oil pressure before
you start it up. Get that video tape and a shop manual too.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 20:35:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
StJames515@aol.com wrote:
Paul Yaw wrote:
What would be ideal is if someone would agree to reproduce a given design,
which could be optimized on the dyno. Any takers?
Paul Yaw and Tracy Crook: I would be interested in this idea as I am at the
point where I need to finalize a manifold design for my own project. If you
guys can give me a sketch of a combo unit, I will build it and let you test
the result.
Also,. Paul, will you elaborate on what constitutes an "independant runner
manifold"???
TIA
Tommy James
Tommy please take a look at this compact
intake manifold and build it out of blue foam and plain
epoxy fiberglas as a test item. Send it to Paul Yaw.
Let me know if you need help in some way with more details or
what ever. I can re-design it slightly to make it possible
to change the length of the intake tubes for dyno tuning
purposes.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 20:43:21 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Fuel vapor separation.
Archie Frangoudis wrote:
In all out piston racing engines, (normally aspirated), we only polish the
exhausts.
The intakes are reshaped +ACY- smoothed, then flowed. In some instances, the
intakes must be coarse blasted to keep the vapor in suspension.
We even prick punch certain areas to induce turbulence when necessary.
Another thing that keeps reversion down is that every time an intake pulse
makes a transition, is should enter a slightly larger area, (or tube),
this creates a +ACI-dam+ACI- effect, and stops the wave from contaminating the
combustion mix (from exhaust pulses) ,or from destroying venturi velocity
(intake)
on carburated vehicles.
Archie
We are kind of beyond carbs Archie :-)
Most are using electronic direct port fuel injection and you don't
have to worry about vapor separation.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 20:27:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Tracy Crook wrote:
The reason for the improvement at ALL engine speeds is the variable port
timing. Mazda made a big deal out of a simple plenum chamber. Once
again, the DC setup IS utilizing pressure waves, and so it is rpm
dependant. The absolute best power boost from pressure wave tuning will
occur with an independant runner manifold. A plenum in fact is simply
the easiest way to feed several runners from a single throttle body
assembly.
Here is the only point that I think we really disagree on Paul Yaw.
There is a
significant difference between a plenum chamber and a "dynamic chamber"
(DC). ( Wish Mazda had come up with a less hokey name for it.)
Your comments about the plenum chamber reducing the amplitude of pressure
waves is absolutely true and shows me that you do understand how they work.
But, the DC is a different animal and Mazda wasn't just putting a new name
on the plenum chamber. For the DC to function, the two rotors must be
connected to opposite ends in order for the pressure wave energy to be
effectively reflected from one to the other. Another key point is that the
cross sectional area of the DC is not much different than the runners
themselves. It's not really a chamber at all. If it were, the pressure
wave would be attenuated as you pointed out.
In looking more closely at the data from Mazda, I also agree that the delay
of the manifolding is beneficial to the DC effect as well. Mazda did not
spell this out but this is my conclusion based on their data. The
fundamental characteristic of the DC that really helps in the aircraft
environment is that the effective runner length that the rotors "see" is
the total length from one rotor intake port to the other, which makes things
a lot easier to fit under the cowl.
<snip more from Paul Yaw>
I would like to point out that the lower manifold half is where the
majority of the airflow restriction occurs. When I flow test these
pieces, I first flow the ports themselves. This gives me a baseline
number. I then add the rest of the induction system piece by piece, and
record the airflow numbers as I go. The biggest whammie occurs when the
lower manifold half is bolted up. Nasty piece!
Paul Yaw
Tracy Crook wrote:
I also agree that Mazda's lower 6 port manafold is a real piece of junk. I
do think it can be significantly improved with a little work though. Just
removing all that barrel valve actuating linkage helps a bit and of course,
streamlining the square corner of the valve itself helps a lot too. Its
nice that we have the freedom to do this in airplane use. It would probably
not be very satisfactory in a car. BTW, have you ever tried this Paul? I
figured as long as we are stuck with the six port endhousings, we might as
well make the best of the factory manifold.
I'll tri sending the Mazda Dyno chart in JPG format and see if it works this
time.
Tracy Crook rws@altavista.net
The HP in this chart is somewhat disappointing.
Where did that chart come from Tracy?
I hope your implementation of it generates more HP or I am going
to build one of my wrapped up pigtail manifolds and send
it to Paul Yaw for testing :-)
BTW I took a look at a six port and I think the entire dividing
wall between the two parts can be ground away. Epoxy weld
can then be poured in there to streamline it.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 22:29:24 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Corvette LS-1 V8 inake manifold
Here is a picture of the Chevy LS-1 nylon intake manifold.
It is a wrapped up, pigtail, compact manifold just like
my drawing.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Sat, 23 Jan 1999 22:34:37 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Data Source?
Bill Freeman wrote:
Paul,
I got the message from Marc, and then the chain
data at the end. Did he put that out, or did you add
it? Trying to get to the source.
Marc sent it to me. It was one of the few files on the
zipped stuff he sent I could handle.
How is it that the industrial drive ratings are in the
16 to 27 hp range (per inch) and the other ratings
quoted are 40-100 hp per inch? Is this for automotive
horsepower ratings? A 3-6X difference is very hard
to cover up with handwaving. What is going on here?
Any automotive (or motorcycle) based power estimates
are extremely deceiving. It only takes about 15-20 hp to
run a car down the road at 65 mph. Even a VERY heavy
loaded pickup going up a steep interstate at 65 mph will
see a max of about 100 HP, and even then for only 5 minutes
or so. Cruising a 250 hp rotary at 75% will have 187.5 HP
running thru it for HOURS, not seconds or minutes. Cars
only see these loads for 2-3 seconds at a time.
Comparing any automotive application is VERY deceiving.
AC conditions are most like industrial applications, and
not at all like automotive applications, except in Germany,
and even there the traffic limits the max continuous speed
and thereby max continuous HP.
Bill
I think they are automotive duty cycle HP ratings.
Makes sense as that is Morse's main market.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sat, 23 Jan 1999 22:38:22 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Engine / Prop Thrust
larry k cox wrote:
Hi Paul,
I realize that it isn't very academic, but sometimes up here at fly-ins
we compare aircraft engine/prop thrust by tying the tail to a post with a
couple of ropes with a spring scales inserted in the line. Pulleys can be
used to adjust for spring scales that are too small. Of course the data
is general and raw but it is easy to compare the thrust of similar
planes and engines with dissimilar props etc. You can sure tell the
difference in thrust of a C180 with a standard prop and a comparable C180
with an 88in. seaplane prop. You can also see the difference between a
Super Cub with a tired engine and one with a fresh engine. You can also
tell the difference before the engine is leaned properly and after.
Before initial flight, I think I would use this simple method to tweek
engine and prop for maximum thrust output, and even compare with aircraft
of similar weight and engine power.
Larry Cox lkcox2@juno.com
Delta Junction, AK.
Sounds like fun. See my homemade dyno and thrust test stand
drawing on the News Letter web site.
Opps! I see you are using Juno... that won't work. Sorry!
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 00:30:48 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: New composite intake manifold design
I re-drew the compact intake manifold for composite
construction and smaller intake pipes as per
Paul Yaw's suggestion. The plenum is larger and made
in two halfs for modification of the pipes if necessary
to re-tune the manifold. the two halfs can be bolted
together with a bunch of 6-32 screws and nuts and
sealed with RTV.
Inch and a half styrofoam sheet is cut out to
a three inch radius 1.5 inchs wide. It is then carved
to a round shape. The resulting male pipe molds are then
covered with long strips of plastic to act
as a separator for the epoxy fiberglass tape wound
around the male molds.
Common guys this is going to work. Somebody build one
and send it to Paul Yaw for dyno testing.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 00:42:47 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Boost Pressure
V. E. Welch wrote:
Paul,
What would you recommend as the maximum boost pressure for a turbo on a 13B?
Vince
I would guess 10 psi boost is doable. You should go with a big
intercooler, ceramic apex seals and good knock sensors. (two)
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 09:06:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Design
Marc Pedings wrote:
It occcurs to me this data could be for automotive
low duty cycle use which would explain the descrepancy
with the MEHB data.
No, it isn't. It is for primary industrail and commercial application.
Shock loads, torque reversal, etc.(as per the engineering manual) is
figured into the service factor. I highly recommend anyone acquiring
their manual.
You might want to double the width just in case.
With the file I am sending, you will see very similair data to the rotary
(160 HP). Service factors in the engineering analysis is based on 24-7
operation at specified horsepower. I specifically requested this and
spent ALOT of time with Morse for an application. Yes, I would recommend
2" width. But hey, 3 inches is even better.
I would use a three inch width to be conservative.
That is not going to add that much weight or cost.
Weight by using their flatter "C" webbed hub style instead of the offset
face "B" style SOLID hub will save you about 40% weight. You will be
suprised that with the additional centrifugal load of the 3 inch chain is
not beneficial for the life of the chain. Note the analysis sheets.
(being sent separate)
If it proved to be over designed in the flying
prototype you could always reduce it later to save
a little weight.
Keep checking the back-lash in the prototype.
If it does not increase rapidly you are home free.
Good ole' Vulkan coupling. Or an automotive clutch plate. After all,
that is what they are supposed to be for: Torque reversal at low RPM's
to keep your manual tranny from chatterting. Although a VulkanUSA
TORFLEX can accomplish the same thing with one drawback. No back stop
incase the rubber or silicone fails.
Marc
I am amazed Marc. I wonder what modern technology Morse came up
with to so improve the silent chain. In your discussions with them
did they mention why their chains are so much better than what
is listed in the MEHB's. I am real curious.
One good thing about a two rotor rotary. No torque reversals.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 09:20:39 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: New composite intake manifold design
Here are more details.
That linen based phenolic is real expensive when
ordered from AirCraft Spruce.
You might want to make the injector holders out of aluminum
and couple them to the composite intake manifold with silicone
hoses and hose clamps.
I tried to keep the sizes of the phenolic blocks as
small as possible. You might be able to cut them
down a little depending on the exact engine you have.
You can port out the phenolic blocks to match the oval
intake ports as per Paul Yaw's suggestion.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 10:10:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: New composite intake manifold design
Marvin Kaye wrote:
Hi Paul,
Your new intake manifold assumes a lot of space under the cowl... it is
really quite a large device, probably 2/3 the volume of the engine block.
I know there is no way I could fit that thing under a Lancair cowl and
still have room for an exhaust system and other things. Additionally your
new design suggests that the plenum is going to have to be self-supporting,
and as such is going to have to be made with a foam or honeycomb core to
keep from collapsing when the throttle is closed. I would suggest that you
go back a bit to your original design and use the intake tubes as the ribs
for the plenum. It could still be taken apart by means of the flanges you
have shown, but it should be built around the tubes over another release
layer so the tubes provide the stiffening to keep the outer layer in shape.
This would also reduce the outside diameter quite a bit and make fitting
the exhaust runners less problematic. Just a few thoughts.
<marv>
Feel free to make modifications. I just felt a larger plenum
would keep Paul Yaw happy :-)
With six layers of epoxy 10 oz fiberglass I don't think it will collapse.
You can bond fiberglass/foam pillars to the tubes
to support the plenum if you are worried about it.
If you want to try a smaller plenum:
The plenum is made in two parts and is symetrical so the parts
can be made on one male mold. Just cut it down until it fits
over the tubes and we will get Paul Yaw to test it on the dyno.
Yes. As I recall there is not a lot of
room in your cowling unlike say, a Glass-Star or RV-6.
Also if you are mounting your engine plugs up there is even less
room for this type of manifold. In that case un-wrap it and wrap it
around the engine. That's the beauty of composites. Try to squeeze
in pipes at least 24 inches long. Try going stright down for
a few inches before doing a large radius 180 and then going up.
BTW I have a simple alternator bracket design I am getting ready to upload
so there is no real excuse for plugs up. It mounts where the air conditioner
normally mounts. You will also have to cut off the neck on the water
pump and weld a plate on it.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 10:22:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Operating RPM
V. E. Welch wrote:
There has been several posts that seemed to imply that 6000 to 6500 RPM
would be an acceptable max for airplane use of the 13B. If a PSRU is sized
to produce 2750 prop RPM at 6000 engine RPM (2.18:1) then running the engine
at 70% for cruise (4200 RPM) would only generate 1926 prop RPM, this seems a
little low. Am I missing something here? What do you feel that a good
cruising RPM would be for maximum reliability and longevity of the
powerplant? What limit should be set for the max engine RPM?
Vince
BTW 70% RPM is not necessarily 70% HP. Manifold pressure is
the best indication of percent power.
Max RPM depends on how you tune it. The other problem is if the
prop gets much smaller in diameter its efficiency falls off.
So all things considered max RPM comes out about 6000 to 6500 RPM
with a 2.18:1 PSRU. If you want more performance naturally
aspirated go to higher reduction PSRU.
Cruise is what ever you would like with a fixed pitch prop.
Unlike a piston engine things in the engine are not stopping and
reversing direction so RPM is not that hard on a rotary.
Tracy is encorporating MPG in his fuel injection system so you
can set cruise to the MPG you would like. If you are in a hurry
of course you could cruise at 5000 to 5500 RPM probably with
out hurting the engine providing all temps are within limits.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 13:20:16 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Exhaust & Intake tuning lengths.
Archie Frangoudis wrote:
Do not think I can make SnF.
Am contemplating a Performance GT, but in conversation, does not look like
it will be available until late this year.
It normally uses a 350 Chev of 300hp. ( simple, and inexpensive for me),
but......... I am somewhat intrigued and enamored
by the use of a rotary of approx. the same hp.
While here, Is it practical to machine conventional rotor housings for
peripheral port?
If so, are there prints available for location,size, etc?
Thanks, archie
I know of no prints but there are some section drawings and a lot
of picture. Racing Beat (and Everett Hatch I think) rolls their own.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 13:23:23 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Stock intake manifolds
Lonnie Wood wrote:
For those of you using the stock manifold parts for making a
Tracy Crook type intake here are some tips.
Where the lower portion bolts to the engine you will notice that
it can move around a lot on the installation bolts. Make a couple
of bushings to keep the manifold in alignment. The proper size
4130 tubing works well. Bore the holes in the manifold if you need
to fit the bushing. Then make a gasket that fits the manifold
exactly. Put this gasket on the engine with bolts and your newly
made bushings and see how well the ports line up. Do this as well
on the next section of manifold. On mine I found I had to grind out
the manifold as well as the ports on the engine to get a perfect
alignement.
In some places there was a 1/8" misalignement.
I do not know if this will make a big difference in overall power
but hey, couldn't hurt.
I also cut away and carved 1/2 of the weight of the lower manifold.
Was a hell of a lot of work. It would probably have been easier starting
from scratch.
Thanks to Tracy for inspiring me to scrap the much to heavy
dynamic chamber.
Lonnie
rwood@iceinternet.com
--
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 13:24:38 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Corvette LS-1 V8 inake manifold
Archie Frangoudis wrote:
If someone wants to experiment with lengths, diameters, or just take a
closer look, I have a couple of the pre-production prototypes for lending.
Yes, LENDING.
In production, these were cast in a proprietary lead-solder based medium.
Archie
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______________________________________________________
Date: Sun, 24 Jan 1999 13:41:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds real world data.
Brent Regan wrote:
The following facts are based on empirical knowledge, direct observation and
published data.
After the intake port opens, a low pressure pulse is produced. This pulse
propagates along the intake runner until it reaches the end (the end being the
point where the diameter of the runner increases significantly) where it inverts
and returns as a high pressure pulse. It has been demonstrated that the
characteristics of this pulse (amplitude, duration, slope) are proportional to the
air requirements of the engine at that throttle setting and RPM. The runner length
should be set so that the returning pressure pulse coincides with the closing of
the intake port. For proper wave reflection the runner must terminate in a full
radius bell mouth (Radius >25% ID for >90 degrees). The absence of the bell mouth
will result in a vena contracta significantly smaller than the runner ID and
attendant flow losses.
I specify a one inch radius bell mouth on the latest design but that is
easily changed.
The intake tube ID should be selected so that the mean air velocity during the
intake period is 100 meters per second (3937 inches per second). For a 40 cuin
rotary at 6000 RPM and a Ve of 1.0 the intake runner diameter should be 1.313 (1.50
tube with a 0.065 wall). For a Ve of 1.3 you want an ID of 1.497 inches.
Is 1.5 close enough? :-)
At 6000 the port open duration is 0.0075 seconds. Sea Level speed of sound is 1100
ft/sec so the propagation distance for the port open period is 99 inches. The peek
amplitude of the of the induction pulse occurs between 25% and 30% of the initial
port opening, therefore the optimal propagation length should be between 40% and
50% of the total. The runner length is 1/2 the propagation length or, in this case,
between 19.8 and 24.75 inches. Actual length must be determined empirically.
Variable length induction is pointless on an aircraft engine.
I suggest slightly longer so torque peak occurs closer to cruise RPM for
BSFC improvement reasons.
Exhaust lengths always seem to end up between 26 and 31 inches (regardless of RPM)
and their diameters are proportional to the amount of horsepower they are flowing
(0.025 square inches per horsepower seems about right).
Paul's pig tail induction, while cleaver, suffers two drawbacks. It has no bell
mouth on the end of the induction runner and the large angle the flow is turned
through will cause the wave front to skew, reducing it's peek amplitude. This is
because the path around the ID is shorter than the OD. This is the same effect that
requires track and field runners to start in a stagger, so they all run the same
distance, and finish in a line.
I added the bell mouth in the last design. What can I do to adjust for
the skew or is it something one must live with? What do you estimate this
wrap up is going to cost in the way of HP?
Get whatever turning you need to do done as close to the port as possible and then
run a straight, parallel wall pipe for the remainder.
In 1984, the peripheral port 12As we were building for Daytona were making 200
horsepower and 175 ftlb at 6000 RPM. Peek torque of 190 ftlb was at 7000 RPM (255
Hp). A 13b should be 8% better. If you could tune for that 190 ftlb at 6000 then a
13b at 205 ftlb and 6000 RPM will make 234 Hp. The 4 rotor Le Mans engine made
448.6 ftlb at 6000 (556 Hp) or 224.3 ftlb (278 Hp) for a 2 rotor.
I want a turbo normalized 26b motor in my Lancair IV-P. Hmmmmmm....
Brent
I am blown away Brent. Wonderful info. Easily put to practical use.
This and selcted messages are going on the web site.
Thanks a bunch Brent.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 14:10:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Tracy Crook wrote:
Paul Lamar wrote:
The HP in this chart is somewhat disappointing.
Where did that chart come from Tracy?
I hope your implementation of it generates more HP or I am going
to build one of my wrapped up pigtail manifolds and send
it to Paul Yaw for testing :-)
BTW I took a look at a six port and I think the entire dividing
wall between the two parts can be ground away. Epoxy weld
can then be poured in there to streamline it.
Paul Lamar
Gee, I thought 160 HP at 6000 rpm was pretty good considering the context.
Remember this is an auto manufacturers chart which means the test was
conducted with ALL the auto accessories, exhaust system, that lousy factory
manifold with the square corner barrel valves etc. It is not much of a
stretch for me to believe that 20 more HP can be had from a cleanup of
intake tract and free flowing exhaust.
No dyno here but I did see an increase in rpm on my test stand engine with
propeller load. My manifold fits easily under the cowl along with water &
oil cooling systems and I have out-climbed other RVs with 160 HP Lycomings
(and one with 180 HP Lycoming). The cost to build was under $25 and took
less than 6 hours to fabricate.
I suspect that your pigtail design would give slightly better performance
if done right but I would never get it to fit any of the available spaces
under the cowl of my RV-4.
RV-6's are side by side so they have more space than tandem RV-4's and Rv-3's
the RV-8 has the RV-6 type cowl.
BTW Everett Hatch's intake manifold was an exact implementation of what Brent
recommended and sounds like it would fit in almost any upright engine
installed in almost any cowl. Even Lancairs with side mount alternators.
Allen Tolle was able to go over 230 MPH with this engine in an RV-3
in the Sun & Fun 100 mile race. Everett claimed over 200 HP.
See the picture taken in Everett's shop attached. everhat1.jpg
One of my newsletter subscribers is trying your idea of eliminating the
bridge between the ports in 6 port housings & reshaping. I think its a good
idea if executed properly.
You already have the chart from my last message so I won't send it again.
It was from a Mazda SAE paper (partial) that someone sent me but I never got
the cover sheet so I don't know the number. It might be the one Paul Yaw
referred to. The title sounded right.
Tracy Crook rws@altavista.net
It looks like it might be from a real old paper because of the low HP.
So that 83 SAE paper sounds about right. 160 HP and 654 cc sounds
like an early 13B engine.
Thanks Tracy.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 16:08:58 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Another comment on knock sensors
MAR34807@aol.com wrote:
My 3 rotor has 3 knock sensors, 1 in each housing like
the 13Brewtt, fwiw....
Yes! I thought some of the stuff on the RX7 list was wrong.
Nobody is on there checking.
Now all we need is a way of reading those knock sensors.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 16:22:13 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Operating RPM
Marvin Kaye wrote:
At 10:22 AM 1/24/99 -0800, you wrote:
V. E. Welch wrote:
There has been several posts that seemed to imply that 6000 to 6500 RPM
would be an acceptable max for airplane use of the 13B. If a PSRU is sized
to produce 2750 prop RPM at 6000 engine RPM (2.18:1) then running the engine
at 70% for cruise (4200 RPM) would only generate 1926 prop RPM, this seems a
My game plan is to redline the (13B turbo) engine (and develop max HP) at
6300 RPM. This gives about 2890 prop RPM, probably a bit on the high side
but shouldn't be a problem with a 68-70" prop. I'm also planing for cruise
RPM to be around 5300 (or 2430 prop RPM), and will tune the engine for max
torque at this point. Interestingly enough, the recent dyno chart uploaded
by Paul Yaw for a 12A engine shows the peaks in just about the right places
for this regime and would be just about what I would hope for on my
installation. Obviously getting there will be the trick, but I hope this
gives you some food for thought.
<Marv>
I want to remind people that that chart was for a carb 180 HP 12A. A 13B
should do about 200 HP with the same level of technology just because
of the increased displacement alone. Even better with EFI.
So far not too many people other than Everett Hatch has achieved
that 13B rotor motor power level in an airplane.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 17:51:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Messages in digest from? & Hi temp epoxy.
Carl Stevens wrote:
MAR34807@aol.com wrote:
Paul, any way this email could be "digested" like other email lists? I know
this may present a problem for attachments, but they could be sent
seperately?
FWIW-there seem to be many more messages now!
I'd second that if possible. Maybe a majordomo setup? I know there are
a few programs that allow digest or single message options.
Carl Stevens
P.S. I have a call into Jon Sharp to see what they are
using for their epoxy system on the baffels. I think
I remember him telling me it was a Shell product that required
a 110 degree cure and a post cure bu has a pretty high T.G.
I think you missed the message from Shell.
Look on the NL web site below and read the instructions for building composite
intake manifolds. Therein you will find all the intructions for using
hi temp Shell epoxy.
I believe the guy that wrote that messages is Jon Sharp's crew chief.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Sun, 24 Jan 1999 19:51:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Composite manifold heat soak.
Alfonso Lebron wrote:
I am not an engineer but it seems to me that the hottest it will get, after engine
shutdown, will be due not the heat collected in the cowl but rather that directly
transmitted from the block to the lower manifold then to the composite piece since
now there is no flow of air and fuel to cool it.
Had anybody tried to grasp an intake manifold after engine shutdown? I guess it would
be hot enough to let go.
If I happen to be wrong, an explanation would add to my education, thanks
Alfonso Lebron
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______________________________________________________
Date: Sun, 24 Jan 1999 19:55:28 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: GlaStar engine
Jim2130@aol.com wrote:
Do you have any plans to offer rotary engine packages (firewall-forward?) for
the Stoddard-Hamilton GlaStar?
I don't but it seems like a good business for someone
to get into judging by the response we are getting with this
news letter. However stuff like that is risky for a business.
You might want to plan on doing it yourself.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Sun, 24 Jan 1999 21:57:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Silent Chain Design]
Marc Pedings wrote:
Paul Lamar Wrote:
I am amazed Marc. I wonder what modern technology Morse came up
with to so improve the silent chain.
Hmm. I believe we are talking about two different animals here. Ramsey makes
the silent chain. It's ratings are MUCH more conservative than HyVo. Tell ya
what :-)
One silent type chain is like every other silent type chain
whatever it is called.... HyVo or what have you.
There are steel links with teeth on one side that are held together
with pins that work on sprockets that look like course tooth gears.
I will be glad to scan in the pertinant excerpts from their
engineering manual and some of their applications. I am not sure if I have a
Ramsey Tech manual, but I will check. If I have it, I will scan it too for
comparison. IF not, I'll jog to Applied Technologies and snag one. Plus, that
will give me the opportunity for everyone to have a more legible copy. I have
TONS of manuals for VARIOUS other products if anyone wants them made
available. I have price lists too from various local supply houses.
is listed in the MEHB's. I am real curious.
MEHB...? sorry, I didn't catch what that abbreviates.
MEHB = Mechanical Engineers Hand Book. The most famous of which
is Mark's Standard Handbook for Mechanical Engineers.
$125 at Borders or Amazon.com
One good thing about a two rotor rotary. No torque reversals.
VERY VERY TRUE! Ahhh. the beauty of Felix's work!
Marc Pedings
I know they have made some changes in the pins that hold the
links together. Rather than slide they sort of roll. Is that
the trick they use to justify the extrodinary HP ratings?
Three to six times better is hard to believe.
This, I would think, would only affect the wear and maybe the efficiency
of the drive. It would also reduce the strength of the chain all other
things being equal.
Maybe they came up with unobtainium to make it out of :-)
I need to talk to a Morse engineer that can tell me why their chain is
so much better than everybody elses.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Mon, 25 Jan 1999 07:22:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Reverse engine rotation for twin.
George Moore wrote:
Paul,
I was a little confused by the posted question by Jean Prudhomme. Was
Jean asking about reversing the rotation of the rotors and eccentric or
turning the engine 180 degrees and using the front snout on the reversed
engine as the drive ? The reason I ask, is in reference to past
discussions over making a 4 rotor by joining (2) 13B's with a coupling.
If you could drive one prop from the front end of one engine, would
the lack of a thrust bearing surface for the now reversed force on the
eccentric shaft become the downfall of this arrangement?
Just curious, as usual, why you coudn't take power off of the front
end of the eccentric shaft ?
IMHO I think you would be asking for trouble. The shaft diameter
on the front of the engine is much smaller.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Mon, 25 Jan 1999 07:27:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Single rotor engines
Paul Mikonis wrote:
Hi Paul,
Any references to single rotor engines cut from 2-rotor jobs? This is
similiar to 1/2 VW
concept. ( For a retiree economics is a driving factor.) Application
might be a small plane
for EAA member. regards Paul
See the newsletter web site below for examples of one rotor engines.
They are indeed cut down from two rotor engines.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Mon, 25 Jan 1999 07:37:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Year Models 13B suitable for AC use.
David Morris wrote:
G'day from DMRH.
In regards to the different types of engines available from the 80,s
onwards you-all should consider simplifying things like we do here in
the land of OZ.
Rather than understanding each year of production we place the RX's in
"series" or versions. Take a look at the table below.
1st gen................SA series..................series I..............78-80
...........................................................series II.............81-83
...........................................................series III............84-85
2nd gen...............FC series.................series IV............86-88
...........................................................series V.............89-91
3rd gen...............FD series..................series VI...........92-95
...........................................................series VII..........96-98
...........................................................series VIII.........99-??
Now the American market only went as far as the series VI but here in Oz
we got the series VII aswell.
The talk between all you guys centres mainly on the series IV vs V
engines. My opinion would always be to use the series V engine as Mazda
did a total re-design of the engine for 89 onwards which still carrys on
to this day. The difficulty some will find is the series V's
electronically controlled oil metering pump as oppossed to the series IV
's mechanical one, but thats easily fixed.
The series V turbocharger flows better due to a different "twin scroll"
design (thats were the TURBO II sticker comes from) & the manifolding on
the NON-turbo 13B is completely redone. etc etc.
Consider it.
This system works remarkably well here in Oz ( & NZ for what it's worth)
REgards
David Morris
http://www.3rotor.com/dmrh
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______________________________________________________
Date: Mon, 25 Jan 1999 13:52:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Volumetric Eff. & the Moller engine.
Jeff Spitzer wrote:
Paul Yaw wrote:
Jeff Spitzer-You mentioned 130% VE for one of the Moller engines. Do
you know what the horsepower output was? If so, at what rpm?
Paul Yaw
The Moller engine displaced 530cc per rotor for 1060 total. We were making
150 BHP at 7500 RPM. The engine was normally aspirated with peripheral
ports. Note that some of that airflow may have been going straight out the
exhaust during the overlap and we actually didn't figure out how much we
were trapping.
Jeff Spitzer
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______________________________________________________
Date: Mon, 25 Jan 1999 13:55:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Jeff Spitzer wrote:
Tracy Crook wrote:
To respond to your reply, I agree about the function of tuned pipes /
inertial tuning etc. I freely admitted that I greatly simplified the
explanation. My main point was that there was a significant difference
between them and the "Dynamic Chamber" (DC) technique developed by Mazda.
Just because they both use pressure waves does not mean they are the same.
The DC function does not primarily rely on a tuned length but rather the
fact that one rotor happens to close its intake port and enter the exhaust /
intake overlap period (which is the source of the pressure wave in this
case) during the last portion of the other rotors intake stroke. This
would happen even if the runner length were zero. I am not saying that zero is
the best runner length because as I stated before, even a DC manifold can
take advantage of inertial tuning as well.
Sorry, but this is just not true. The speed of sound is strictly enforced
regardless of manifold design. All pressure waves have a time when they are
generated and a finite time to travel to some other point of interest.
Whether those waves bounce off a box or an open end of the pipe, the timing
for them to reach their destination when they can do the most good will be
a function of pipe length, air temp (speed of sound) and RPM regardless of
configuration/type.
Jeff Spitzer
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Mon, 25 Jan 1999 13:57:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Inherent balance of multi-rotor stacking?
Jeff Spitzer wrote:
At 04:48 PM 1/23/99 -0800, you wrote:
Unlike a piston engine they are all in total balance.
The only thing that varies is the number of torque pulses.
One pulse per rotor, per rev.
Paul Lamar
Yes, but a 4-rotor can be balanced without counterweights.
That's pretty sweet.
Jeff Spitzer
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Mon, 25 Jan 1999 14:00:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 12A dyno run chart.
Jeff Spitzer wrote:
Paul Lamar wrote:
BTW Paul Yaw, That is way too broad of a torque and HP
curve can you peak it up some for aircraft use :-)
Paul Lamar
And herein lies one beautiful thing about rotaries: Flat torque! That's
nothing, Ive seen truly flat torque curves on peripheral port engines that
span 1500 RPM+.
Jeff Spitzer
One? Heck yet another beautiful thing!
Paul Lamar
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______________________________________________________
Date: Mon, 25 Jan 1999 16:15:25 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 12A dyno chart.
Jeff Spitzer wrote:
I want to remind people that that chart was for a carb 180 HP 12A. A 13B
should do about 200 HP with the same level of technology just because
of the increased displacement alone. Even better with EFI.
So far not too many people other than Everett Hatch has achieved
that 13B rotor motor power level in an airplane.
Paul Lamar
That's because the chart was for peripheral ports, no?
Jeff Spitzer
Don't know. Paul Yaw?
Paul Lamar
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______________________________________________________
Date: Mon, 25 Jan 1999 20:05:50 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Source for used engines in the US
StJames515@aol.com wrote:
Hi Phil,
I would try Mazmart in Atlanta (see http://www.mazmart.com) (I think the
contact was Bob McMillan) for a late model junk engine. I paid $425 a year or
so ago for a '89 6port 13B core engine (no injectors, alternator, etc.). I
tore it down and could not measure wear except in the seals. The overhaul kit
cost double that.
Good shopping
Tommy James
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______________________________________________________
Date: Mon, 25 Jan 1999 22:55:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Source for used engines in the US
Archie Frangoudis wrote:
I may be a neophyte to the realm of rotaries, but my first purchase was a 13B core for +ACQ-300.
I realized that in order to accumulate enough usable housings, etc. this would be costly.
I found it more economical to purchase complete cars ( wrecks, worn outs, or just plain sick).
With one of these, you get everything. Transmission, radiator, oil cooler,
electronics, and many items to trade or bargain with.
I have never paid more than +ACQ-200. for a complete car, many of which were derivable.
Keep your eyes open, they are out there.
Archie
Pardon my ignorance Archie but what does ACQ mean?
How do you get rid of the stuff you don't need? Do the junk
yards take it off your hands.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Tue, 26 Jan 1999 08:08:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Determining the tube loads in motor mounts.
Wrathall Mark wrote:
Fantastic article Paul. This is the kind of info that everyone who knows
it, assumes it is so easy, it doesn't need to be written. And all those of
us who didn't know it can't remember enough school physics to start.
Thanks, keep it up.
Mark Wrathall
Thanks Mark.
I thought about it for six months before I got around to doing
it. I also want to thank Alex Kozloff for clarifying my thinking
on this. Thanks again Alex.
Any any ideas on how to make it clearer?
Paul Lamar
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______________________________________________________
Date: Tue, 26 Jan 1999 08:33:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
CC: Allen Lyons CARB <alyons@arb.ca.gov>
Subject: Source for used engines in the US
Archie Frangoudis wrote:
Paul, I do not know what ACQ means. Is it coming through on my messages? If
so, I do not know why.
The bodies of RX7's are easy to sell, I usually get +ACQ-50 or so, and have
people calling frequently.
Perhaps I should open a salvage yard for RX 7's. Scrap yards, and one Auto
salvage company will haul all my discards away for free. Not a bad deal overall.
Archie
Yes. See above. What kind of computer are you using Archie? Modem?
Browser? Email program? Keyboard?
If you had some cheap land in the desert and you threw up a steel
shed and bought old RX7's some day they would be worth a lot.
There are a lot out here in CA because of the ludicrous smog rules
and the ludicrous price Mazda is charging for parts.
A Mazda igniton module is $300 each and there are two on the distributor.
The law says you cannot change the stock Mazda ignition system and still
pass smog in CA.
I once had a smog inspection station bounce my
Dodge Caravan because I had a peice of rubber hose with a bolt stuck
in it sealing a tap in the intake manifold. I had to get an official
rubber cap part from Dodge to plug that hole. We are talking about less
than one ounce of rubber. The smog inspector said he would be fined
$700 if he was caught passing the Caravan with the hose on there.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Tue, 26 Jan 1999 10:55:56 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Source for used engines in the US
Anderson Ed wrote:
Paul, around my neck of the woods, Vienna, VA, I am able to get ignition
modules from salvage yard for $50 if I take them off myself. Most are
simply left on the firewall when they yank the engine. Takes a little
work but you can get six for $300{:>}. Archie might want to check hislocal foreign car salvage yard.
Ed Anderson
The kind I am talking about are mounted on the 1985 RX7 12A distributor.
I am about to res-erect my wifes RX7 sitting in the hangar and I need two
known good ones. If anybody has a couple let me know the price.
If I can't get it through smog I might use the engine to test intakes.
I also have a 1976 13B Cosmo sitting in there but in another ten years
it will be classified as an antique and will not have to pass CA smog :-)
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Tue, 26 Jan 1999 11:20:40 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
facilitator1@juno.com wrote:
Paul <rotaryeng@earthlink.net> writes:
Sport Aviation had articles on Exaust Gasses and
Pipes , Etc. Was in the last 6 mo I think. Quite an
engineering discussion. Virg
Not too useful for rotaries as I recall.
To each his own, gasses, pulses etc don't care where they come from, they
all obey the same laws. Virg
True Virg and I did re-read the article after you mentioned it.
It was in the January 1997 Sport Aviation page 34.
Was there a later one than that?
They mentioned a computer program in there that could calc
engine tuning. I might like to talk to the guy and see if
it is adaptable to the rotary.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Tue, 26 Jan 1999 12:01:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ionization current knock detection
David Munday wrote:
Since knock detection has been a recent topic here I thought I'd
forward this little gem to the list. Does anyone here know what an
ionization current knock detector is or how it works? Would it be
more or less difficult than using DSP to sort out the acoustic knock
signature from all the noise up there?
Found on rec.aviation.homebuilt
" I'm working on a CDI-based IGN system that will use Ionization Current
measurement for Knock Detection (like the Saab system; nice for aircraft in
high-vibration environment; the acoustic knock detectors don't work too well in
noisy aircraft FWFs). There's a company in Australia that has an EXCELLENT,
well-designed, inexpensive kit, with real quality parts, for playing with CDI (you
have to wind yer own pulse transformers, tho, so the slothful needn't apply).
That's where I got my base CDI stuff I'm using. Had to import the bloody things, I
did! Much rather had gone down undah to get them tho; they have some eXcellent
wines in Australia these days, mates. B)"
--
David Munday - mundayde@muohio.noise.edu
My email address is not noisy.
Webpage: http://www.nku.edu/~munday
PP-ASEL - Tandem Flybaby Builder - EAA-284 (Waynesville, OH)
"Adopt, Adapt, and Improve" -- Motto of the Round Table
Don't know the answer to that until I see a skematic for the kit.
What you do is measure the resistence across the spark plug gap
just before you fire the spark plug. This can then detect pre-ignition.
You somehow must protect the circuitry from the impending
high voltage spark energy. I don't think a relay will cut it.
I am not sure if Saab ever put it into production.
David Morris might have some info on this kit since he is down
there. Dave what do you say??? <dmrh@3rotor.com>
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Tue, 26 Jan 1999 12:06:16 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A.M.W. AKA 2Si PSRU.
kwalsh@inhale.com wrote:
AMW was always claiming that thay had a 200hp 2 stroke, and they kinda did.
Using their cylinders as a modular type arrangement, they made a flat six
that was put in an SCCA open cockpit car and evidentally did quite well.
No plane ever flew with one, to my knowledge. I believe Nick Jones used
the 3 cylinder version in his little Lightning Bug single place plane. Nick
also did the larger White Lightning 4 place kit that never really caught
on.
Kevin
The only possible problem I can foresee is the flat six two cycle has six
torque pulses per rev while the 13B has two, much bigger, torque pulses
per rev.
Paul
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______________________________________________________
Date: Tue, 26 Jan 1999 12:42:20 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A lot of things.
ingenuir@ix.netcom.com wrote:
On 01/25/99 23:15:44 you wrote:
Bill Martin wrote:
Paul,
The oil cooler in the pictures is a sheet metal pan welded over the existing
oil pan to make a chamber about 3/8" in depth with an inlet on one end and
exit on the other.It is pinned in the center to preclude expansion.
Hello, Paul & Bill & group:
These photos are great in showing real hardware and design nuances. Thanks.
Some hints for future photo documentation:
1) Please either zoom into the key features or crop or blow up the picture as
possible. Space around the subject just adds bandwidth to the attachment and
creates graininess when we zoom in to view it.
2) Please include a yard-stick or yo-yo in the same plane whenever possible.
This enables viewers to scale the details either for understanding or analysis.
3) Try to take near isometric or near orthogonal views. Again, this gives
better sense of scale and proportion.
4) Additional views (few, please) may be needed.
5) Captions help, e-mail descriptions of the subject really help.
6) Light the subject to maximize contrast range. (OK, a black pan will still
have limited contrast range.)
7) Paul, I know Linux & Win-95 long names help to find these files, but I use
my old Win3.1 "legacy" version of MS-PowerPoint to re-color your gray and
turquoise backgrounds to white and to attach labels to stuff I print. It's much
happier with 8 character names.
What works best for me is get three inch prints, scan in at 150 dots per inch
and crop like mad. As far as the 8 character file names I try but
it is tough keeping track of hundreds of photo's. Switch over to
Linux Gary :-) Gimp photo shop comes for free. Paul Lamar
Gary Moir
ps: Note that if you spell M-O-I-R fast enough, you can say my name without
adding the "e". My Scottish ancestors apparently decided to save the extra ink,
so we just use the 4 letters in the name. :-)
pps: I just got back to the message where you described your process of
calculating the firewall reactions and asked if I agreed with your method.
Basically, you are scaling the physical geometry to solve the reactions as
vectors. I sent some notes on this before. That's a good approach, however, you
need to account for 6 "degrees of freedom", that is: You need to keep the
engine from moving or rotating in any of the three orthogonal directions. I
think your calculations assume only the vertical direction matters due to
symmetry. I will look at the details and do an independent calc as soon as I
wrap up the end of Jan. taxes. I do offer a quick-look NASTRAN analysis
starting at $200 for other customers, so that is available to anyone that's
interested. I plan to set up a demo case soon. It looks like I need a table of
3-D locations of the strut ends and engine/psru/prop cg's to do that.
I can be reached at:
GAMA Ingenuirity, Inc., 310-378-7076, 800-303-GAMA,
ingenuir@ix.netcom.com
The loads in the other directions are all low compared to the loads
as a result of a six G pull up or a hard landing. Both of which are
stright down. Airplanes rarely experience even a one G side load
unless of course you can fly a sustained knife edge. Very few people
are going to be doing any six G push overs from an inverted position.
Thrust loads are small at speed. Max thrust might occur at max climb
rate.
However thanks for bringing these points up Gary Moir :-)
Paul Lamar
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______________________________________________________
Date: Tue, 26 Jan 1999 13:06:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 12A dyno run chart & a broad torque curve.
Gary Palmer wrote:
Paul,
Just a comment on the thread re non applicability of a broad power
curve for aircraft usage. I would agree that if one has a constant speed
prop, then there is less value in a broad power curve. However, many of us
have fixed pitch props that are optimized for cruise. Consequently, we need
a broader power band to obtain better take-off performance from a coarse
pitched prop. Consider my own Lancair 235, with a 115HP Lyc O235; I could
only turn up a bit over 2,000 rpm for takeoff (approx. 70 HP) and normally
cruised at 2500 rpm. More power at rpms 25% below cruise would be extremely
advantageous. It looks like the rotary will help there and let me take a
simpler brute force approach to obtaining better takeoff performance.
Regards.............Gary Palmer
Gary, good to hear from you. I did not visit during Christmas time
as I thought the Ottawa EAA Chapter was empty because it was so
cold with so much snow. Do they plow that road out to the chapter
building?
My point was the low speed efficiency of a fixed pitch prop so
overwhelms the torque factor that there is little point in a broad
engine torque curve. Don't forget with a 2:1 PSRU the engine
is turning 4000 RPM when the prop is turning 2000 RPM
Here is a trick. Calculate the acceleration, MPH and distance covered
by the airplane every 0.1 second during its take off run.
You will find that high initial thrust
or HP has little to do with the take off performance. What really matters
is high thrust starting about 40 MPH when the runway real estate is
dis-appearing at a faster rate. Luckily the prop efficiency and prop RPM
gets much better starting around this speed range.
I can do this with a Quick Basic program, a prop efficiency curve and a
HP curve. I think most people could care less when it comes to programs of
this type. Am I wrong folks? (If I could find the time.)
Paul Lamar
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______________________________________________________
Date: Tue, 26 Jan 1999 15:43:28 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ionization current knock detection
Jeff Spitzer wrote:
What you do is measure the resistence across the spark plug gap
just before you fire the spark plug. This can then detect pre-ignition.
You somehow must protect the circuitry from the impending
high voltage spark energy. I don't think a relay will cut it.
I am not sure if Saab ever put it into production.
David Morris might have some info on this kit since he is down
there. Dave what do you say??? <dmrh@3rotor.com>
Paul Lamar
My guess, from a non-electronic guy, is that you measure the ionization
current during the spark and from that deduce cylinder pressure. Higher
cylinder pressures (due to detonation) would require higher voltages? I
dunno, maybe I should just shut up.
Jeff Spitzer
You might be right Jeff I don't really know for sure. I only remember
what I read about the Saab system. Sounds like what you propose would
be easier to do.
Another issue is detonation as opposed to pre-ignition.
As I recall detonation can take place after ignition.
Unfortunately one cannot search the SAE web site for papers prior
to one year ago. Is anybody in a University situation that
can computer search for the SAE paper on the Saab setup?
Paul Lamar
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______________________________________________________
Date: Tue, 26 Jan 1999 23:53:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Calculating the time,distance & speed for takeoff
Gary Palmer wrote:
Paul,
Basically I think you are suggesting a program to do a simple
integration. Given my Calculus is non existent these days, I would be
interested in a simple Basic program. In fact if Quick Basic is essentially
similar to MS basic, I could probably translate to an Excel spreadsheet with
Visual Basic code for those who have bought the whole enchilada from Billy
boy. I am assuming you have the two tables needed to drive the integration.
I for one would find it very useful, and educational. I am still not
totally convinced since in my case the rpm stays low (2100 to 2200) until I
start to level out and accelerate from best climb speed of 120 mph.
Sounds like you have too much pitch Gary.
Over Christmas things were probably very quiet, we only have a
couple of hardy types attempting to fly this winter. The back road isn't
plowed this year but you can simply walk across the ramp from the First Air
parking lot if you are up again this winter.
Regards.............Gary
OK I have thought about it a little bit and here is what I need.
I need a simple text data file in this form.
MPH verses prop thrust and prop RPM
Example:
0,50,1900 'static thrust and RPM
5,75,1950
10,100,2000
15,125,2050
20,130,2110
25,133,2200
30,139,2280
etc.
etc.
up to 70 MPH
The guy who made the prop should have this data.
I have a program written making an assumption on the rate
of change of prop eff and HP as a function of speed but it is
a guess.
Paul Lamar
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______________________________________________________
Date: Tue, 26 Jan 1999 23:56:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ionization current knock detection
Byron Brandon Ward wrote:
Unfortunately one cannot search the SAE web site for papers prior
to one year ago. Is anybody in a University situation that
can computer search for the SAE paper on the Saab setup?
I'm at University of Michigan and would be glad to search for you but I
have no idea how to.
Byron
Tell the librarians what you want Byron and they should do it for you.
Use key words like "Saab" "SAE", and "ignition".
Paul Lamar
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______________________________________________________
Date: Wed, 27 Jan 1999 00:00:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: A.M.W. AKA 2Si PSRU.
Bill Martin wrote:
Paul,
The motor mount is a piece of 6061 - 1/2 " thick which you can see is butted up to the
block.On each end,I machined a pocket for Lycoming mounts and welded extentions to match
the thickness of the mounts.I then took the Mazda transmission case front and cut off 2
1/2" and welded a half inch plate cut to fit inside at the right dimension to accept the
a.m.w. case.The case comes with two locaters which my machinist installed incorrectly so I
had it done again after welding a plug in the wrong hole location.The second time it came
out right.The rubber isolater is captured by a ring inside so it can't expand and it really
locates the center very well.A lot of good engineering in this box-if it works""
Again,the starter problem is a real one so anyone interested in this box should talk
to a.m.w. about this problem before purchasing it.I have examined this box and I believe a 12" flywheel
can be installed ahead of the other flywheel and made to work but it will be a real
engineering project .To locate the new location for the starter and keep it inside the cowling.
Of course,it's all in fun.
Bill Martin
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______________________________________________________
Date: Wed, 27 Jan 1999 00:07:13 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Source for used engines in the US
George Moore wrote:
Paul,
I went back and looked at Archies other posts, and everywhere that
+ACQ- showed up, it became obvious that it was meant to be a $ (dollar
sign) ! It's really amazing what different systems can do with the
simplest of texts.
In re-reading Archies posts, is he saying that he has used Rotary
engines for sale, since he has mentioned that he buys whole cars and
sells the empty hulk to scrap yards ?
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______________________________________________________
Date: Wed, 27 Jan 1999 06:00:32 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Source for used engines in the US
TERF Email wrote:
Scrap recycling yards will pay for the steel. I have sent LOTS of em' out
that way. Not lots of cash maybe $30 or so depending on the market. Of
course you have to get em' there. Sometimes the steel yard will come and
get them if you ask nice. You usually won't get paid though. For what it
is worth..
Matthew Tait mtait@terf.com
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______________________________________________________
Date: Wed, 27 Jan 1999 06:02:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Source for used engines in the US
TERF Email wrote:
I have a number of these ignition modules hanging around. I could part with
a couple and even test em' first to make sure they are OK. Email me
directly
This brings me to another point. I have about 5 or 6 complete sets of
excellent 12A engine sets I have kitted out ready to be cleaned and
re-assemble if anybody would like to buy some. As I mentioned I am moving
my business and cash is much easier to carry. ;-)
Thanks for the commercial I will now return you to your regularly
scheduled newsletter.... Thanks
Matthew Tait mtait@terf.com
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Wed, 27 Jan 1999 09:22:05 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Source for used engines in the US
Archie Frangoudis wrote:
In reply to George Moore's question regarding my engines for sale,
I am not selling any engine, transmission, or related parts. Just
accumulating them.
(just in case).
Keep the info flowing, gentlemen. I teach part-time at a local college, but
am still learning myself.
Archie
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Wed, 27 Jan 1999 09:27:12 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Tracy Crook wrote:
See! I told you this could take months!
OK, here's the way I see this (which of course could be wrong and anyone who
can show me that has my thanks).
Start with rotor 1 as it closes its intake port. Due to inertial effects
in the intake path a pressure wave is generated (you already understand this
so I wont elaborate). The DC manifold is designed in such a way that this
pressure wave is reflected over to the rotor 2 intake port which (here is
the important part ) is OPEN. This happens regardless of engine speed,
manifold length, etc. Now, as Paul Yaw pointed out, the timing of the
pressure wave arrival at rotor 2 is best if delayed just a bit (to make the
wave arrive near the last part of intake stroke) and the manifold length
helps here. BUT, this delay does not require the kind of length called out
by the classic tuned pipe manifold. If this distinction seems like a moot
point, you have probably never had to shoehorn all the engine & systems into
a tight, streamlined airplane cowl. Trust me, this is a big deal.
BTW, you are generally right on the money technically Jeff so I was
surprised at you statement about pressure waves being distorted in curved
manifolds. I do not have a good enough theoretical background to argue it
on that basis but all theory must yield or be modified by real world
results. There is probably no more critical application where the integrity
of pressure waves and tuning effects are more important than in a musical
instrument. As a brass musician I can tell you that curves in the tube
(both conical and cylindrical bore) have no significant effect on this.
This has been verified by very detailed spectral analysis of the pressure
waves emerging from brass instruments built specifically to test this
theory.
My thanks to Paul Yaw for his offer to help in testing of manifold design.
I am reluctant to accept, knowing that Dyno time is expensive and is his
stock in trade but I just may have to take him up on it!
OK, enough of this goofing off for me. Back to the engine monitor design.
Tracy Crook rws@altavista.net
Thats good to hear for my compact wrapped up pig tail intake manifold as
well.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Wed, 27 Jan 1999 09:36:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: IVO prop problems
Castle, Ron wrote:
Paul,
I forward the email regarding the IVOP prop problem that Mr. Bates
referred to, with the pitch of their prop, Thought the response was a little
vague.....
Ron Castle
----------
From: ivoprop@pacbell.net[SMTP:ivoprop@pacbell.net]
Sent: Tuesday, January 26, 1999 2:41 PM
To: ron.castle@lmco.com; LesDrag@aol.com
Subject: Re: Fwd: FW: IVO prop problems
We have our Magnum prop on a Glasair II RG IO360 going 245mph
Another pusher aircraft in the Turkish Airforce is going around 300mph
Ron/Ivoprop 800 367 6676
Well perhaps they have a two foot diameter spinner blocking the
bad part of the blade. Or perhaps they have added cuffs.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Wed, 27 Jan 1999 10:14:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: IVO prop problems
Castle, Ron wrote:
Paul,
I forward the email regarding the IVOP prop problem that Mr. Bates
referred to, with the pitch of their prop, Thought the response was a little
vague.....
Ron Castle
----------
From: ivoprop@pacbell.net[SMTP:ivoprop@pacbell.net]
Sent: Tuesday, January 26, 1999 2:41 PM
To: ron.castle@lmco.com; LesDrag@aol.com
Subject: Re: Fwd: FW: IVO prop problems
We have our Magnum prop on a Glasair II RG IO360 going 245mph
Another pusher aircraft in the Turkish Airforce is going around 300mph
Ron/Ivoprop 800 367 6676
BTW I have also heard that when used on a pusher the bad part of
the blade near the hub is masked by the wake of the fueslage so it works
better.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Thu, 21 Jan 1999 11:31:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P-51 duct coordinates
I asked David for the coordinates of the P51 cooling duct
with the hopes we could scale it for cooling the rotary
engine. It is probably the best cooling arrangement
for a liquid cooled aircraft engine ever developed.
This is a DXF file for all you people with a CAD
program. For those that don't I will try to upload
a gif that could be scaled.
The file is both attached and included as plain ASCII text
in the body of this message.
Paul
David Lednicer wrote:
Try the attached file - I think it should be what you are looking
for.
-------------------------------------------------------------------
David Lednicer | "Applied Computational Fluid Dynamics"
Analytical Methods, Inc. | email: dave@amiwest.com
2133 152nd Ave NE | tel: (425) 643-9090
Redmond, WA 98052 USA | fax: (425) 746-1299
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ENDSEC
0
EOF
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 21 Jan 1999 13:21:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P-51 duct coordinates
This is all I have so far but I am working on more.
Don't forget this is cooling about 1600 to 2000 HP.
I would like to get the coords on sections
along the duct.
The bump is the oil cooler I think.
Paul
--
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 21 Jan 1999 13:36:22 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Coordinates on P51 duct
Jeff wrote:
BTW, the
"ideal" cooler is a type called counter-flow. If you can image the air
flowing from front to back and the oil flowing from back to front (not side
to side as in your cross flow alternatives) then the hot oil would be
cooled by the heated air and the cooled oil would be cooled by the fresh,
cool air. These heat exchangers have the best package and cooling
efficiency.
Jeff Spitzer
This might have applications in the P51 duct. Lets assume for the moment
you have two 3 inch rad cores belly to belly making up a six inch thick
rad for this P51 type cooling system. You scale the linear dimensions
by half giving one quarter the rad cooling surface area for
400 to 500 HP cooling capability. Just as a rough first cut.
It is best to put the hot water
in the back rad first and then then the front rad.
Or maybe better yet... three two inch thick rad cores. Water in back...
out front.
Paul
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______________________________________________________
Date: Thu, 21 Jan 1999 20:48:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Coordinates on P51 duct
Jeff Spitzer wrote:
This might have applications in the P51 duct. Lets assume for the moment
you have two 3 inch rad cores belly to belly making up a six inch thick
rad for this P51 type cooling system. You scale the linear dimensions
by half giving one quarter the rad cooling surface area for
400 to 500 HP cooling capability. Just as a rough first cut.
It is best to put the hot water
in the back rad first and then then the front rad.
Or maybe better yet... three two inch thick rad cores. Water in back...
out front.
Paul
Yes, this is typically referred to as a multipass crossflow arrangement and
is definitely more efficient than a single pass of 6" thick.
Jeff Spitzer
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______________________________________________________
Date: Thu, 21 Jan 1999 20:52:11 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct
Jeff Spitzer wrote:
Equally important to the duct design is its integration to the airframe.
Simply scaling and copying the p51 duct is of no interest to me.
Understanding the engineering behind it (known as design intent) is much
more useful. That would entail things like diffusion rates vs. turning
angles and percent of internal and external diffusion. A curving diffuser
is still a cut and try (a la North American) or CFD effort for good
performance. The duct entry and exit are dependent on outside flow
conditions and therefore have little particular value taken alone.
Jeff Spitzer
I assume you would put it in the same place the designers of
the P51 put it. Namely well forward of the trailing edge
of the wing to take advantage of the thin boundry layer
and high pressure area found there.
Paul
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______________________________________________________
Date: Fri, 22 Jan 1999 00:04:39 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P-51 duct coordinates
V. E. Welch wrote:
I'm running Autocad LT 98. When I tried to look at the file I got an error
on line 1049 that aborted the load.
I am working on it. It appears to be only two dimensional anyway
so I am trying to obtain the three dimensional coordinates.
See a later message for an attached gif.
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Fri, 22 Jan 1999 00:18:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct
Alfonso Lebron wrote:
This site, which was once posted in this newsletter is what I am using as a
guide in the cooling system construction for a GP-4. The only point that is
still not very clear is the width of the radiator. Is it the same a 300 mm. as
compared to a 600mm. wide radiator?
http://www.inforamp.net/~raac/techtips.html
Any imput would be interesting to say the least.
Alfonso Lebron
We have had that link on our News Letter web site for quite some time.
The P51 style duct would be ideal for your GP-4. Unfortunately I am
still missing cross sectional information but I am working on it.
I cannot emphasize enough how important properly ducting the cooling
system is.
It is as least as important as the amount of HP generated by the
engine.
Paul
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Wed, 27 Jan 1999 14:05:48 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Cooling and the P51 duct.
Alivic@wport.com wrote:
Paul,
I'm still in the dreaming stages of rotary power for my
still in the box RV8. I've been out to see Trracy Crook and have all of
his literature as well as Bruce Turrentine's tapes. All of this stuff
adds to my enthusiasm for this type of development project.
I wrote a few weeks ago regarding the potential virtue of
ceramic coating the rotors in hopes of containing more of the energy of
combustion. Today's question deals with cooling which seems to be a
very common problem with all auto conversions. I have been studying the
WWII designs and followed the thread here recently. Does utilizing a
fluid to oil heat exchanger have potential to meet all the cooling needs
of a 13B assuming a well designed P51 type radiator under the wing of an
RV8?
Your input is greatly appreciated. Tony Livic
We are not sure yet. Several people are building water to oil
heat exchangers as we speak. It will just cool the oil if it
works. You still need a water rad. I just recieved the sections
on the P51 duct from David Lednicer. Stay tuned.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Wed, 27 Jan 1999 14:41:09 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct sections.
Here is the parent DXF files for those of you that have a CAD
program.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Wed, 27 Jan 1999 14:52:42 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Cooling and the P51 duct.
Bktrub@aol.com wrote:
Has anyone tried taking a regular aluminum heat exchanger and mounting it in
the oil pan in such a way that the oil must pass through it to get to the
sump? It could be mounted in on a baffle plate similar to the oil/ air
separator that Tracy Crook used. It could be a cheap, light and easy to
fabricate oil/water heat exchanger. -Just thinking out loud.
Brian Trubee
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Wed, 27 Jan 1999 15:28:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: David Lednicer <dave@amiwest.com>
Subject: [Fwd: P-51 duct]
David Lednicer wrote:
Attached is a CAD file containing sections through the inlet and
exit duct.
-------------------------------------------------------------------
David Lednicer | "Applied Computational Fluid Dynamics"
Analytical Methods, Inc. | email: dave@amiwest.com
2133 152nd Ave NE | tel: (425) 643-9090
Redmond, WA 98052 USA | fax: (425) 746-1299
---------------------------------------------------------------
Name: ductsec.dxf
Part 1.2 Type: Plain Text (TEXT/PLAIN)
Encoding: BASE64
Thank you very much for this file David. I think it will help our
readers solve their cooling problems. Do you think it can
be scaled down 50% without losing too much of its
functionalty?
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Wed, 27 Jan 1999 21:26:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Cooling and the P51 duct.
Carl Stevens wrote:
WWII designs and followed the thread here recently. Does utilizing a
fluid to oil heat exchanger have potential to meet all the cooling needs
of a 13B assuming a well designed P51 type radiator under the wing of an
RV8?
We are not sure yet. Several people are building water to oil
heat exchangers as we speak. It will just cool the oil if it
The Soob people are using a water/oil cooler called the Modine
cooler, apparently with good success. It gets the water up to
temp faster and keeps the oil temp cooler. The Soob list archives
have many recent listings.
Carl
"I will find a way, or I will make one."
-- Seneca
--
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Wed, 27 Jan 1999 21:33:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Ionization current knock detection
Byron Brandon Ward wrote:
Paul, I have the SAE paper you were looking for. "Closed Loop Ignition
Control by Ionization Current Interpretation". I havn't read it yet and
probably wouldn't understand it anyway, but in skimming it it seems to be
what you were looking for. The paper number, by the way, is 970854 if that
helps. I have a hard copy and can scan it and attach to an email if that
will work for you (10 pages). Don't have access to a fax machine
unfortunatly so I can't do it that way.
Byron
Good work Byron. Try to use OCR on it. If that does not work don't bother
scanning it as ten pages of jpg's will create a huge file.
You can scan just the picture and skematics. I am particularly
interested in the skematic.
It is better for those that are interested to just order the
paper from the SAE if it has to be scanned as ten large jpg's.
Thanks for researching that. It might be the answer to the knock
problem with high boost turbo's.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Wed, 27 Jan 1999 21:52:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct sections.
I just want to say how lucky we are to recieve those
P51 cooling duct sections. This information could have
easily been lost to antiquity. This duct design played
a major role in winning World War II. When the Germans
saw P51's escorting B17's over Berlin they were stunned.
At that point they knew they had lost the war.
This duct design, developed in a wind tunnel, must have cost
a fortune in 1940 terms. It was major factor in the P51's
excellent fuel efficiency and hence it's long range.
I hope all of you will seriously take this into consideration
when planing the cooling system of your rotary powered airplane.
As time goes on I will try to convert these drawings
into something more useful for building a foam male mold
for purposes of laying up a fiberglass scale replica
In the mean time if you have specific questions on
dimensions let me know.
BTW if anybody has trouble with that DXF file let me
know and I will re-send it as a zip file.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 01:30:19 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: IVO prop problems
Tracy Crook wrote:
We have our Magnum prop on a Glasair II RG IO360 going 245mph
Another pusher aircraft in the Turkish Airforce is going around 300mph
Ron/Ivoprop 800 367 6676
Well perhaps they have a two foot diameter spinner blocking the
bad part of the blade. Or perhaps they have added cuffs.
Paul Lamar
Numbers by themselves don't mean a lot. I want to know what the same
airplane would do with a known good prop. An I0 360 powered RV-4 with its
gear hanging out went faster than that Glasair II RG which is a cleaner
airplane.
Pushers do have an advantage with the IVO because the hub area is in
disturbed air already.
Tracy Crook rws@altavista.net
--
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 01:32:36 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Cooling the oil with an oil cooler imbedded in the pan.
Tracy Crook wrote:
Bktrub@aol.com wrote:
Has anyone tried taking a regular aluminum heat exchanger and mounting it in
the oil pan in such a way that the oil must pass through it to get to the
sump? It could be mounted in on a baffle plate similar to the oil/ air
separator that Tracy Crook used. It could be a cheap, light and easy to
fabricate oil/water heat exchanger. -Just thinking out loud.
Brian Trubee
This is the preferred implementation as I see it. I would have gone that
way but I was too impatient to stop & solve the interference problem with
the oil pickup tube. It could be done.
Tracy Crook rws@altavista.net
--
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Thu, 28 Jan 1999 01:42:47 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 12A Dyno Chart BSFC
Bill Freeman wrote:
Paul,
Did you note the BSFC number of 0.58 on the dyno
chart. Yikes! This could almost be a turbine.
Bill
It is not far off an aircooled aircraft engine at full power.
Fortunately it gets a lot better at cruise as Tracy has found
you can run a rotary at 100 degrees lean of peak unlike
an aircooled aircraft engine.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
______________________________________________________
Date: Thu, 28 Jan 1999 07:34:12 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Torque pulses in rotary engines verse piston engines.
BCGARDNER@aol.com wrote:
Ahhh, Paul,
I'm back to asking you to fill in the gaps in my engineering education. Given
Bill Freeman's clear and intuitive explanation of torque pulses in a rotary,
I'm left wondering what Everett Hatch was trying to solve with his complicated
approach to torsional resonance. Isn't this a related problem? Hatch spent
lots of time and money solving this one.
I got down my copy of Tracy Crook's book and re-read his explanation of how
using a light prop changed the resonance frequency. But I'm still trying to
put together how the rotary has less negative torque but can still develop a
frequency vibration that Everett Hatch found tore apart their drive train.
Care to take a crack at discussing torsional resonance?
TIA.
Barry Gardner
Everett was a great engineer but even the best of them can be wrong
once in awhile.
I think Everett had a dyno shaft coupling that was either previously cracked
or happened to have a resonent frequency that coincided with the frequency
the rotary was putting out at max power around 6500 RPM in his case.
In all due respect Everett never fully developed his gear box to my
satisfaction. In fact Allan Tolle had one of the fastest times
flying in the Sun & Fun time-to-climb contest. Unfortunately a PSRU bearing
failed in the Sun & Fun 100-mile-race knocking Allan Tolle's RV3 out
of the final flyoff in the time-to-climb. Admittedly Everett was running
laughing gas in the engine but so was Pushy Galore.
Both Bill Freeman and I were there with Everett and Allan.
Everett did not believe in clutch disk centers. He attempted to
build a direct drive PSRU. It might have worked given more development
time. We owe a lot to Tracy and others that have flown the Ross unit
for at least 600 hours proving the concept of a clutch disk center
combined with a Ford C6 planetary reduction.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 07:45:05 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Tracy Crook wrote:
snip.....
OK, here's the way I see this (which of course could be wrong and anyone who
can show me that has my thanks).
Start with rotor 1 as it closes its intake port. Due to inertial effects
in the intake path a pressure wave is generated (you already understand this
so I wont elaborate). The DC manifold is designed in such a way that this
pressure wave is reflected over to the rotor 2 intake port which (here is
the important part ) is OPEN. This happens regardless of engine speed,
manifold length, etc. Now, as Paul Yaw pointed out, the timing of the
pressure wave arrival at rotor 2 is best if delayed just a bit (to make the
wave arrive near the last part of intake stroke) and the manifold length
helps here. BUT, this delay does not require the kind of length called out
by the classic tuned pipe manifold. If this distinction seems like a moot
point, you have probably never had to shoehorn all the engine & systems into
a tight, streamlined airplane cowl. Trust me, this is a big deal.
Sorry! I don't think I am going to trust you on this one Tracy :-)
Everett Hatch was able to get a classic tuned pipe intake manifold into
Allan Tolle's RV 3 without the additional volume of the cheeks on
the cowl that you enjoy. Jeff did indeed shoehorn all the engine & systems
of the rotary into a Moller ducted fan cowl.
I am not saying the dynamic chamber is any better or worse than a classic
tuned pipe intake manifold. I am saying the jury is still out :-)
snip.....
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 07:49:41 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 12A Dyno Chart BSFC
Paul Yaw wrote:
Paul wrote:
Bill Freeman wrote:
Paul,
Did you note the BSFC number of 0.58 on the dyno
chart. Yikes! This could almost be a turbine.
Bill
It is not far off an aircooled aircraft engine at full power.
Fortunately it gets a lot better at cruise as Tracy has found
you can run a rotary at 100 degrees lean of peak unlike
an aircooled aircraft engine.
You can expect a slightly better BSFC with a stock 13B, as opposed to a
stock 12A which is what you saw on the last post. (The low powered
engine) The stock 12A exhaust port is so restrictive, (58 cfm at 25" of
water pressure drop, as opposed to about 98 cfm for the 13B!) that the
pumping losses during the exhaust cycle are HUGE. On a stock 13B, with
an air fuel ratio in the mid to high 13's (peak power mixture) you could
expect about .52-.53 at peak power, and .49-.51 at peak torque. This of
course is with a full power mixture. I have never tried to lean one out
on the dyno, so I can't make any claims about a lean cruise mixture.
Paul Yaw
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______________________________________________________
Date: Thu, 28 Jan 1999 08:59:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Peak Torque Measurement in 12A Dyno Chart BSFC
Carl Stevens wrote:
On Thu, 28 Jan 1999, Paul wrote:
Paul Yaw wrote:
... On a stock 13B, with
an air fuel ratio in the mid to high 13's (peak power mixture) you could
expect about .52-.53 at peak power, and .49-.51 at peak torque. This of
course is with a full power mixture. I have never tried to lean one out
on the dyno, so I can't make any claims about a lean cruise mixture.
I hope I did not miss this already but where do you measure peak
torque? I have heard that the Torque curve goes pretty flat over
a wide power band so it the measurment taken at the beginning of the
flat? Please excuse my ignorance, I have looked out on the webpage
but do not see the dyno chart posted yet. (I have a slow connection
at home so all large {>30K} postings are filtered out on my serverbefore I download mail. Long story...)
Carl
It is at least from 4000 RPM up which you will be using in an
aircraft engine. The dyno charts are not on the web site.
The pictures and charts on this newsletter are at least
50% of the content. So if your ISP (Juno is the worst with
none at all) cannot handle that I suggest changing ISP's.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 09:26:39 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Tracy Crook wrote:
Sorry! I don't think I am going to trust you on this one Tracy :-)
Everett Hatch was able to get a classic tuned pipe intake manifold into
Allan Tolle's RV 3 without the additional volume of the cheeks on
the cowl that you enjoy. Jeff did indeed shoehorn all the engine & systems
of the rotary into a Moller ducted fan cowl.
I am not saying the dynamic chamber is any better or worse than a classic
tuned pipe intake manifold. I am saying the jury is still out :-)
snip.....
Paul Lamar
Sure, it can be done. Racing Beat developed one of the tightest
installations I ever saw. BUT, Everett, Moller, and Racing Beat were
working with a budget that I'll bet was well into 6 figures. My entire
firewall forward budget was less than $5200. and that included
instrumentation & PSRU. THAT'S the big deal :-)
Tracy Crook rws@altavista.net
Nah! Not Everett! He was just a farmer :-) What is the big deal
about four 1.5 inch pipes 24 inches long wrapped over the engine?
I think your toes are hurting Tracy :-)
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 12:24:27 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct mold section listing half size.
StJames515@aol.com wrote:
Paul,
Good Morning!
Not being an engineer and not having CAD are a real handicap for this
builder/experimenter, so if you could communicate the P-51 info in a more
usable format, it would be greatly appreciated. This is a mod that I have
long been considering and have collected some design information, but do not
feel I have sufficent understanding to proceed when the time come.
Many Thanks,
Tommy James
Tommy, Here is a listing of every line segment in the P51 duct.
the text file is 173K. With this information you can make templates
two inches apart from one end of the duct to the other. With
these templates a male mold can be made for a half size
P51 cooling duct.
I have zipped the file with PKzip to reduce the download time.
Please plot one or two of the sections for us on brown paper and let
us know how it looks.
BTW if you try to print the file it will be about 85 pages so
I don't recommend doing that.
Load it into a text editor and just print a few pages at a time.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 16:23:31 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Torque pulses in rotary engines verse piston engines.
Phil Williamson wrote:
Paul wrote:
Bill Freeman wrote:
Paul,
You are probably confusing Phil on this one.
Bill,
I'm always plenty confused reading posts from you guys.:-) After reading some of
this stuff, I'm amazed I even have a damn pilots license.<g>
What's great is as the conversation goes on, some things begin to clear up...this
torque pulse thing not being one of them. I which Everett were still alive because
he was so dang handy (it took me all of 10 minutes to fly to his house). Course, I'd
be drivin' him nuts asking him to clear up some of my questions.
What I do now is just assume what Paul (and the rest of you folks) tells me is
true.:-) I save 99% of the posts here so I can re-read them many times.
Take care guys
Phil
Think of a boat anchored in the surf. Every time a wave comes along the
boat is raised. That's a torque pulse. If the boat drops below sea level thats
the down side of the torque pulse.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 16:48:57 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Cooling and the P51 duct.
Bktrub@aol.com wrote:
Paul, do you have the address of the website that has the article "Cooling
Systems for Automotive Conversions" By Hans Mayer? The majority of the article
discusses WW1 and WW2 aircraft. Thanks in advance.
Brian Trubee
Its on the Newsletter Web site below. It is the very first link under
interesting web sites. When you click on it look at your browser website
address box and therein will be the address.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 16:46:00 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Jeff Spitzer wrote:
Tracy Crook wrote:
Start with rotor 1 as it closes its intake port. Due to inertial effects
in the intake path a pressure wave is generated (you already understand this
so I wont elaborate). The DC manifold is designed in such a way that this
pressure wave is reflected over to the rotor 2 intake port which (here is
the important part ) is OPEN. This happens regardless of engine speed,
manifold length, etc.
Can you explain how the wave propagation rate, manifold length, and RPM
don't effect the time at which the waves arrive at #2?
BTW, you are generally right on the money technically Jeff so I was
surprised at you statement about pressure waves being distorted in curved
manifolds.
That was Brent. I agree with the theory but do not have first hand
knowledge of the validity. I know that waves are stretched/distorted by
the presence of the boundary layer among other things. In the musical
instrument the effect is a change in tonality compared to a straight pipe
but we are all used to the sounds produced by the curvy system. Try
building a trumpet with straight pipes...I bet it would sound funny. (Also
note the diffences between the flugelhorn and trumpet)
Paul wrote:
Thats good to hear for my compact wrapped up pig tail intake manifold as
well.
Yes, but your manifold has another problem that recently occurred to me.
You should never install injectors perpendicular to the pipe as you show.
The penetration will be sufficient to deposit the fuel on the far wall and
your atomization will be worse than a bad carb. The generally accepted
practice is to try to squirt the fuel down the tube (on the exit of a bend
for instance) and avoid wall contact or squirt onto a hot surface such as
the back of the intake valve.
Jeff Spitzer
I think you will have to tell Mazda Jeff. The Le man's engine used that
arrangement and they were getting 160 HP per rotor normally aspirated.
With timed fuel injection it is like pissing into the wind :-)
Picture of the Le Man's engine. lemanrot.jpg
The little black lump pointing stright down is the injector.
Note: The variably length tuned intake pipes.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 16:52:28 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Leaking seal in Ross PSRU.
Gerry Hess wrote:
Hi Paul;
I finally fired up the single rotor engine in my plane, and noticed
the Ross Drive input shaft immediately began to leak. I recall a
mention of a solution to this problem on the NL. Any ideas? I'm
thinking of replacing the stock seal with a double lipped seal.
Gerry
Tracy has done something with that as I recall.
It might be the finish or lack thereof on the seal
rubing surface. Also check the pressure in the box.
As I recall you have to put a flow restricter in the feed
line.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 16:54:36 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Knock ionization current technical paper list.
Byron Brandon Ward wrote:
Paul,
I think trying to upload this paper is going to be more trouble than its
worth. Here is a list of references however for those that are interested:
1) Lars Eriksson, Lars Nielsen, and Jan Nytomt. Ignition control by
ionization current interpretation. SAE SP-1149 (SAE paper No.
960045):73-79, 1996
2) J. Auzins, H. Johansson, and J. Nytomt. Ion-gap sense in missfire
detection, knock and engine control. SAE SP-1082, (SAE paper No.
950004):21-28, 1995
3) Anson Lee and Jan S. Pyko. Engine misfire detection by ionization
current monitoring. SAE SP-1082, (SAE paper No. 950003):9-19, 1995
4) Nick Collings, Steve Dinsdale, and Tim Hands. Plug fouling
inbestigations on a running engine - an application of a novel
multi-purpose diagnostic system based on the spark plug. (SAE paper No.
912318), 1991
5) A. Saitzkoff, R. Reinmann, T. Berglind, and M. Glavmo. An ionization
equilibrium analysis of the spark plug as an ionization sensor. (SAE paper
1996), 1996
6) M. Hubbard, P.D. Dobson, and J.D. Powell. Closed loop control of spark
advance using cylinder pressure sensor. "Journal of Dynamic Systems,
Measurement and Control", pages 141-420, december 1976
7) I. Glaser and J.D. Powell. Optimal closed loop spart control of an
automotive engine. (SAE paper No. 810058):11-21, 1981
8) K. Sawamoto, Y. Kawamura, T. Kita, and K. Matsushita. Individual
cylinder knock control by detecting cylinder pressure (SAE paper No.
871911), 1987
Hope this list helps,
Byron
Sure does Byron. Thanks a lot.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 17:11:04 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct mold section listing half size.
StJames515@aol.com wrote:
Hi Paul,
WOW! What a guy! Many thanks.!
I will be glad to work on this project for the benefit of others, but give me
a few days to get off the road and focus again.
Tommy James
Tommy I know a guy that may carve that mold out of blue styrofoam
using a 3D router controlled by a PC computer.
You load the DXF in and it routes the foam.
He will probably charge money. I don't know how much yet.
I am working on him. He currently is making
prop cores for Klause Savier.
BTW if half size is too small, scaling to other sizes is trivial.
Also anybody with a CAD program and a large plotter can
plot those sections full size on mylar directly. They then
can be cut out and used as templates directly. Unfortunately
my big plotter is down at the moment.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Thu, 28 Jan 1999 19:40:23 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Which direction to inject?
Jeff Spitzer wrote:
I think you will have to tell Mazda Jeff. The Le man's engine used that
arrangement and they were getting 160 HP per rotor normally aspirated.
With timed fuel injection it is like pissing into the wind :-)
Picture of the Le Man's engine. lemanrot.jpg
The little black lump pointing stright down is the injector.
Note: The variably length tuned intake pipes.
Well that said I still think they would have got better BSFC without
wetting the other wall. Maybe the pipe size, flow velocity, and closeness
to the port was such that the pissing in the wind meant that by the time it
hit the other wall the wall was already gone (and replaced by rotor). Note
that if you impart some momentum to the fuel perpendicular to the flow the
momentum will drive the fuel across until something stops it (a.k.a
Newton's law) I suppose turbulence could help but only in a random way.
Jeff Spitzer
You are forgeting aerodynamics Jeff. The droplets have frontal
area and drag so therefore some velocity in the direction of the
duct is imparted.
I have seen em where they piss upwind..... to get better mixin.
Next time you go out to the ole crick.... piss in the water
and see what happens :-) Its all a function of injection pressure,
air flow velocity and pattern.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Fri, 29 Jan 1999 19:27:40 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Cooling the oil with an oil cooler imbedded in the pan.
Gerry Hess wrote:
Jeff Spitzer wrote:
I think this thing is inside out. Oil has much worse heat transfer
characteristics than water and needs the extra area. I understand that
this unit has double area for water than it does for oil.
Jeff Spitzer
Yes, those were my first thoughts, too. This is electronic heat sink
stock, and I can flip it either way you like. But.. My understanding of
thermal dynamics ( very limited, I will leave it to the pencil pilots!) is
that heat energy excites electron movement in atoms, and the desired state
of any material is one of the least movement (or absolute zero). So in short
heat flows toward cold, to attempt to achieve this state. The higher the
heat, (like pressure?) the faster the transfer. The cooler material is the
water inside the heat exchanger. My thoughts were that the temp difference
would balance out against the poorer transfer rate of oil. The labyrinth of
the internal flow should break up any boundry layer by creating turbulance
in the water flow.
I can probably be proved wrong quickly, but lets hear some reasons, and
discussion before I finish welding this thing up. It seems to be a better
system then the old coil in the oil trick, and I remember back in Contact
magazine, when Tracy Crook built his first cave-man version of his engine(3
Mikuni's) the coil in the oil upped the thermal efficiency of his radiator
as well and caused the engine water temp to run cooler.
Gerry
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______________________________________________________
Date: Thu, 28 Jan 1999 21:40:59 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Paul Yaw wrote:
Paul wrote:
Tracy Crook wrote:
Sure, it can be done. Racing Beat developed one of the tightest
installations I ever saw. BUT, Everett, Moller, and Racing Beat were
working with a budget that I'll bet was well into 6 figures. My entire
firewall forward budget was less than $5200. and that included
instrumentation & PSRU. THAT'S the big deal :-)
Tracy Crook rws@altavista.net
Nah! Not Everett! He was just a farmer :-) What is the big deal
about four 1.5 inch pipes 24 inches long wrapped over the engine?
I think your toes are hurting Tracy :-)
Well, since I prompted this whole argument by whining about Tracy's
message, I feel obligated to state the obvious. Wether or not Tracy's
toes are hurting, he is flying! No matter when the pressure waves
arrive, or how they get there, they are doing it in the air.
Paul Yaw
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______________________________________________________
Date: Fri, 29 Jan 1999 00:11:34 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Phil Williamson wrote:
Paul wrote:
Nah! Not Everett! He was just a farmer :-) What is the big deal
about four 1.5 inch pipes 24 inches long wrapped over the engine?
I think your toes are hurting Tracy :-)
Farmer? ya, right.:-) Last time I was there I saw a fella on a tractor,
but it sure as heck wasn't Everett.<g>
How many folks here (other than Paul) got to see his "farm"? He grew
beans outside and wall to wall engines inside. My first small block chevy was
built with "leftover" engine parts that Everett said was junk (which meant
they wouldn't hold up to racing stress).
Phil
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______________________________________________________
Date: Fri, 29 Jan 1999 00:17:58 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Cooling the oil with an oil cooler imbedded in the pan.
Gerry Hess wrote:
Hi Brian Trubee
Here is the unit I am building to test in my engine. Most dimensions are
given, and the rest are easy to figure out. Off the shelf stock and a little
tig work and some pressure testing, and then we'll see what real world
physics does to it.
Gerry
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______________________________________________________
Date: Fri, 29 Jan 1999 11:35:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Leaking seal in Ross PSRU.
Kruiswyk, Neil wrote:
I had the same problem but it was my own fault. When I was assembling
and disassembling the engine (over and over and over) during
construction, I tried to pull the gearbox off in one piece while the
input shaft was semi stuck in the pilot bearing. The input shaft stayed
and I was trying to pull the sun gear through the oil seal. I nicked
the seal, which caused the leak. It was a 2 minute job to replace the
seal.
Neil
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______________________________________________________
Date: Fri, 29 Jan 1999 11:37:48 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil to water heat exchangers.
Kruiswyk, Neil wrote:
Brian,
Yup, a few of us are experimenting with exactly that. Marv has
built an interesting oil tank with coolant running through it. It has
yet to fly but our numbers would indicate success.
Jim and I are working on an external oil-water exchanger. It is
installed and is working very nicely in the cold Canadian weather.
We've installed temp probes and are building information to share with
the group. Keep your eyes peeled to this group for ground breaking
updates. :-)
Neil
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______________________________________________________
Date: Fri, 29 Jan 1999 11:48:27 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Tracy Crook wrote:
Nah! Not Everett! He was just a farmer :-) What is the big deal
about four 1.5 inch pipes 24 inches long wrapped over the engine?
I think your toes are hurting Tracy :-)
Paul Lamar
Farmer? Good story but.......
True, the manifold is not all that complicated or bulky (there were only 2
tubes) but If you had asked Everett about it (I did) he would have told
you that it would not work without his peripheral ported rotorhousings.
And if you use those you would need his lovely in-port throttle valves to
get it to idle in a civilized fashion. By the time you add up all the
requirements you have spent my whole engine (and maybe airplane) budget on
an intake system and spent 10 years. Everett started working on this thing
in 1985.
Yes! All true! But now we know how to do it thanks to Everett. :-) [P]
I am not trying to argue that my system is technically superior to
Everett's, Paul Yaw's or your (Paul Lamar) approach. My design would
probably come in last at the racetrack or dyno. When I talk engines &
airplanes, it is always with the assumption that the goal is -- To fly
soon, safely, and often. We only have so much time on the planet. I am
willing to give up the last 1% of engine power in order to spend more time
seeing it from the air.
Keep the arguments coming! I love this game almost as much as flying :-)
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Fri, 29 Jan 1999 12:07:53 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds]
Tracy Crook wrote:
Jeff Spitzer wrote:
snip....
Can you explain how the wave propagation rate, manifold length, and RPM
don't effect the time at which the waves arrive at #2?
The wave propagation rate & manifold length do affect the timing and help
delay the pulse to the end of rotor 2's intake cycle where it does the most
good. I tried to point out why RPM did not affect it by using the zero
length manifold example (impossible of course) in the original message. The
timing is not affected because the eccentric shaft, rotor & stationary gears
are rigid and keep rotor 1 & 2 in the same relationship timing-wise to each
other at all engine speeds. When rotor 1 intake port closes (the source of
the pressure wave), rotor 2's intake port is ALWAYS open regardless of
engine speed.
Tracy Crook
I think you need a little help explaining this Tracy. The duct from rotor
one to rotor two is divided into two by the plenum which by wave theory at this
point is atmospheric. So flow through the throttle body is zero. The pressure
at the other end of the duct with the just open port, rotor two, is below
atmosphereic (reference pressure RP for short) which creats a vacumme at
that point.
Nature abhors a vacumme so air starts flowing into the just open port
through the throttle body while the air pulse is traveling down the duct
from the other end, rotor one, at the speed of sound. It passes the
throttle body but for some strange reason (probably the inertia of the air previously
flowing in through the throttle body blocks it) it does not flow out there.
In a little while longer it hits the just closing port on the other end of
the duct enhancing the flow into rotor two.
Is this about right Tracy?
A sequence of drawings would help.
I will send the rest of your message in a bit.
Paul
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______________________________________________________
Date: Fri, 29 Jan 1999 12:09:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Leaking seal in Ross PSRU.
Tracy Crook wrote:
I had no luck with the Ross supplied seal (an expensive Viton seal) and
replaced it with a double lip Buna N rubber seal. It doesn't hold up to the
heat well and has to be changed at 300 hour intervals. Be sure to follow
the remarks Paul made. If these are the things causing your leak, it would
be better to stay with the Viton seal.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Fri, 29 Jan 1999 12:27:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Which direction to inject?
Tracy Crook wrote:
Paul Lamar wrote:
The Le man's engine used that arrangement
As in my drawing on the web site for the composite intake manifold.
and they were getting 160 HP per rotor normally aspirated.
A two rotor version like the 13B would of course be 320 HP.
With timed fuel injection it is like pissing into the wind :-)
Picture of the Le Man's engine. lemanrot.jpg
The little black lump pointing stright down is the injector.
Paul Lamar
Also note that the 13B has an atomizer (little disk filled with tiny holes)
mounted in the injector path to mix things up. Don't know if the Le Mans
engine had this though. I use the atomizers on the primaries but the
secondaries are squirting straight down the pipe so I didn't use them there.
On the other hand, a programming error on my prototype EFI had the timing
reversed (squirting when the intake was closed) and the only noticible
difference was at idle to 2000 rpm so it may not be that big a deal (in
airplanes). I didn't fly it that way so don't know if it affected fuel
economy.
Tracy Crook rws@altavista.net
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______________________________________________________
Date: Fri, 29 Jan 1999 06:41:56 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 13B short block in Sacramento
BCGARDNER@aol.com wrote:
Paul, I don't know if any of your list members are in the Sacramento area but
here's a guy advertising an '86 13B short block. It's almost certainly a six-
port because he doesn't mention a turbo, which had the four-port engine that
year.
FWIW.
Barry Gardner
Subj: (FC3S) [2] '86 parts, all must go!
Date: 01/28/1999 11:54:07 PM Central Standard Time
From: gollum@netcom.com (Smeagol)
Sender: owner-list@teamfc3s.org
To: barx7club@autox.team.net (BARX-7 List), list@teamfc3s.org
(FC3S List),
mazda@mailinglists.org (Mazda List), rx7@world.std.com (RX-7 List)
I still have many parts left over from the blue '86 base model RX-7 I am
parting out. Some of the more major items include:
... 13B short block, automatic transmission,... ignitors,...
Feel free to ask if something is not listed here.
The car is located in Roseville, CA (near Sacramento). Buyer covers
shipping. Open to all offers on everything, all must go immediately.
Someone make me an offer on everything, I'll let it go cheaply. If
you're in the Sac/SF area shipping costs may be avoided, come grab
whatever you want.
Thanks,
Mike
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______________________________________________________
Date: Fri, 29 Jan 1999 13:37:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Kruiswyk, Neil wrote:
I'm with Tracy on this one. If I had the money, time and a
professional Dyno, I would love to experiment on all sorts of things for
the Rotary as it applies to aircraft. Unfortunately, I don't have a
Dyno and very little of the other 2. After 3 different intake manifolds
(all of which worked, but to what extent I don't know) I finally bit the
bullet and went "off-the-shelf" with Racing Beats DelOrto manifold.
Everyone I've spoken to (including Mazdatrix) says it's the best on the
market. It's small, compact (could be lighter) works great and best of
all, I didn't have to built it 3 times.
My 2 cents worth.
Neil
I hear you Neil but somebody has to do it.
A home made dyno/test stand is not
that big of a deal. See the News Letter web site below. Also
for those of you just starting out I recommend building a dyno into
the motor mount if you are interested in getting the best performance
out of your airplane. With a built in dyno you can separate drag
and prop effects from HP effects.
The manifold Neil mentioned above will give less than optimum performance
in an airplane because it was designed to generate max power at
7500 RPM to 8500 RPM in a car. The requirements for a car engine
and an aircraft engine are worlds apart. This is why we are here.
BTW the Mazda paper on the dynamic chamber is SAE 841017 Recent Technology
Development of High-Powered Rotary Engine at Mazda.
The HP chart Tracy uploaded awhile ago came from that paper.
Here is a chart of the pressure wave in a dynamic chamber engine.
At this point (1984), in Mazda engine developement, the dynamic
chamber and six port configuration did not pay off that well
in the 6000 RPM speed range. The HP went up from 140 HP to
160 HP. I think 200 HP at 6000 RPM is do-able with the proper tuning.
The total intake port area for the six port is equal to a peripheral
port according to this paper. In reality the flow may not be equal
because the six port is divided... so skin friction drag in the
two parts is a major factor. If the divider is ground out with
a porting grinder and the resulting passage smoothed with epoxy
filler a great increase in power could result. Don't throw
those six port engines out just yet.
Paul Lamar
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______________________________________________________
Date: Fri, 29 Jan 1999 13:44:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct mold section listing half size.
Jeff Spitzer wrote:
I'll wait and see what Brent comes up with since he asked for the job.
Regarding the plots I'm not ready right now and was only asking about the
plotter for future availability. My job would be very big indeed and I
hope I could pay your friend a reasonable fee for ink, wear and tear, etc
and still save over a repro business.
Jeff Spitzer
BTW guys those are white lines on a black background. I thought the
file was blank when i tried it on a white background :-)
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______________________________________________________
Date: Fri, 29 Jan 1999 19:14:51 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct sections.
MAR34807@aol.com wrote:
I just finished reading the latest EAA mag article about the aerodynamics of
WWII fighters by Dave Lednicer. The P51 cooling duct was discussed in great
detail, and included was the pressure distribution analysis of the "boundary
layer seperation" in the cooling intake and how it affected the different
radiators/coolers/intercoolers. Also looked at was the FW190 wing coolers
(much less efficient). Worth a look! Can't say I understand a lot of
it........... and if it applies at most of our airspeeds!
Where you been? :-) This Sport Av article triggered what we are doing
here.
Paul Lamar
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______________________________________________________
Date: Fri, 29 Jan 1999 20:00:35 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Room in the cowl for a tuned intake manifold.
BTW guys I have been hearing a lot of opinons on here
on why a tuned intake manifold won't fit in one cowl or another.
I am not buying it guys.
Here is a scale drawing of a Lancair cowl with engine installed
in a normal upright position. The Lancair 215/320/360 cowl is probably
the tightest cowl around.
As you can see there is plenty of room for either a wrapped
up ten inch in diameter tuned intake manifold plenum or a 24 inch
stright pipe intake manifold that goes up and over the top of the
engine. The only thing you need do is move the alternator
and mount the engine upright. A slight modification of the
water pump neck is also required. Even four 1 1/2 inch diameter
pipes when bunched together are only 1 1/2 inches high (surprise)
and six inches wide.
See the news letter web site for a bracket that will mount
the alt. where the air conditioner compressor normally resides.
The type of motor mount you choose also has a lot to do with
it. The Questair type mount with the tubes out near the cowl
wall give plenty of room.
Paul Lamar
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______________________________________________________
Date: Fri, 29 Jan 1999 22:40:43 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Cooling the oil with an oil cooler imbedded in the pan.
Brent Regan wrote:
For best power transfer (cooling) the thermal impedance of the two
fluids should be matched. If one fluid has half the heat capacity
(specific heat) it needs to flow (mass) twice as fast or have twice the
area exposed (or 71% more of each).
Think of the aluminum as the impedance matching transformer.
Brent
--
Paul Lamar
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______________________________________________________
Date: Fri, 29 Jan 1999 22:52:27 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: P51 duct mold section listing half size.
Brent Regan wrote:
Got it. Imported fine into Autocad Mechanical Desktop 2.01. It is a 1/2 section
of the inside of the duct. Can you get the outside as well? In particular, the
boundary layer splitter.
I doubt that this will have much application to water cooled conversions as a
significant portion of the duct penetrates the fuselage (see Sport Avi 1/99 p. 88)
making a retrofit difficult.
How does the oil cooler airflow discharge?
Brent
I don't think the fuselage structure is an insurmountable problem.
Perhaps in the case of a Lancair IV where you have the gear.
In a case like that you might want to use Spitfire type rads.
IMHO the composite fueslages are easily modified around this duct.
It is not a high stress area of the fuselage.
I'll have to ask David Lednicer where the air from the oil cooler goes.
I would assume under the water rad.
I hate to ask him for the outside. He has been so helpful so far.
Why don't you give it a stab. David Lednicer <dave@amiwest.com>
Paul Lamar
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______________________________________________________
Date: Fri, 29 Jan 1999 22:58:08 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Paul Yaw wrote:
Tracy Crook wrote:
I am not trying to argue that my system is technically superior to
Everett's, Paul Yaw's
HEY, I don't even have a system. Only some suggestions for sufficient
airflow, and lot's of arguments about timing pressure waves.
or your (Paul Lamar) approach. My design would probably come in last
at the racetrack or dyno. When I talk engines &
airplanes, it is always with the assumption that the goal is -- To fly
soon, safely, and often. We only have so much time on the planet. I am
willing to give up the last 1% of engine power in order to spend more time
seeing it from the air.
Keep the arguments coming! I love this game almost as much as flying :-)
Have any of you noticed that it is much more fun to argue over the
internet? You can take the time to perfect your response, and you don't
have to worry about getting punched!
Paul Yaw
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______________________________________________________
Date: Fri, 29 Jan 1999 23:14:06 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Room in the cowl for a tuned intake manifold.
Bktrub@aol.com wrote:
Hear, hear!
Brian Trubee
Here is another scale drawing showing the Hatch type tuned intake
manifold stuffed into a Lancair 215/320/360. No problem!
Plenty of room! qammlan4.gif
Paul Lamar
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______________________________________________________
Date: Fri, 29 Jan 1999 23:38:10 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Paul Yaw wrote:
OK, here goes the theory behind the magical mystery dynamic chamber.
There are two waves that the dynamic system utilizes. The first is
generated at intake port closing. As the port closes, the intake charge
that was travelling at a high rate of speed is suddenly forced to come
to a screeching halt. This results in a steep pressure rise, and a high
pressure wave will propogate from this point towards rotor #2. The
second pressure wave is generated approximately 70 degrees later as the
intake port of the following chamber is opening. For the first 16
degrees that the intake port is open, the exhaust port is also open.
(This is the overlap period) Since there is a great deal of exhaust
back pressure, a puff of high pressure exhaust gasses will squirt up
into the intake tract. This of course will create another high pressure
wave which will also travel towards rotor #2.
Not necessarily Paul. In many cases the intake pressure is higher
during the overlap period. See the chart below. this is from the
same 1984 SAE paper mentioned before.
Now you have two high pressure waves travelling towards the other
rotor. Mazda found that the greatest increase in volumetric efficiency
occured when the first wave arrived at rotor #2 at BDC, and the second
wave arrived at rotor #2 at intake port closing. For the waves to
arrive at the appropriate time, they must be delayed by approximately
110 degrees of eccentric shaft rotation. If they were not, as in the
case of a zero length manifold, the first pressure wave would arrive at
110 degrees before bottom dead center, and the second wave would arrive
at 40 degrees before bottom dead center. In this instance they might do
some good, but not as much as if they arrived at the proper time. At
6000 rpm for instance, it takes .00306 seconds for the eccentric shaft
to turn 110 degrees. Based on the speed of sound in the manifold, Mazda
determined that the intake passages must be 500 mm., or 19.69 inches
long to delay these waves by .00306 seconds, or the equivalent of 110
degrees eccentric shaft rotation. At engine speeds above and below 6000
rpm, the supercharge effect will be reduced because the pressure waves
will not arrive at the most appropriate time.
I would like to point out that with a proper exhaust system, the second
pressure wave which is initiated by exhaust back pressure will not
exist, and so the remaining wave will need to be delayed by 180 degrees
if it is to arrive at the intake port closing of rotor #2. This (at
least on paper) corresponds to a runner length of 32.2 inches for
maximum effect at 6000 rpm. I should also point out that a high
pressure wave will have the greatest effect on volumetric efficiency if
it arrives right before intake port closing.
Interesting number. It seems very close to one that I have heard
mentioned on this newsletter before.
Paul Yaw
We need to get some of these manifolds on the dyno and see which ones
work the best.
Paul Lamar
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______________________________________________________
Date: Fri, 29 Jan 1999 23:49:03 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Paul Yaw wrote:
Paul wrote:
The total intake port area for the six port is equal to a peripheral
port according to this paper. In reality the flow may not be equal
The flow is not even close! Not because of friction, because of HUGE
amounts of turbulence caused by a really poor design.
Paul Yaw
We are addressing the poor design and turbulence with a miracle
epoxy called (as I recall) JB Weld :-) You pour it into the sixth
port and shape it to your needs. It works!
Paul Lamar
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______________________________________________________
Date: Sat, 30 Jan 1999 00:48:52 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Six port modifications.
This is basicaly what I had in mind as to six port
modifications. Note: the outer pipe size can go
up to 1.75 OD from 1.5 OD.
The rib between the ports is completely removed. sixport.gif
Paul Lamar
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______________________________________________________
Date: Sat, 30 Jan 1999 00:54:40 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Paul Yaw wrote:
Paul wrote:
We are addressing the poor design and turbulence with a miracle
epoxy called (as I recall) JB Weld :-) You pour it into the sixth
port and shape it to your needs. It works!
Paul Lamar
When I say poor design I am referring to the whole manifold, not just
the high speed port. I use a lot of epoxy in my work, and I have found
some putty's to work pretty well. The advantage for me is that I can
shape it before it cures so that I have less work to do afterwards. I
will be happy to flow test anyones port, manifold, chamber etc. It
doesn't take much time to mount it to the bench and flow it, so just let
me know if I can be of help.
Paul Yaw
You know we throw the stock manifold away. Too heavy if nothing else.
Paul Lamar
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______________________________________________________
Date: Sat, 30 Jan 1999 00:52:18 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Dynamic Chamber Intake manifolds
Paul Yaw wrote:
Paul wrote:
Paul Yaw wrote:
OK, here goes the theory behind the magical mystery dynamic chamber.
There are two waves that the dynamic system utilizes. The first is
generated at intake port closing. As the port closes, the intake charge
that was travelling at a high rate of speed is suddenly forced to come
to a screeching halt. This results in a steep pressure rise, and a high
pressure wave will propogate from this point towards rotor #2. The
second pressure wave is generated approximately 70 degrees later as the
intake port of the following chamber is opening. For the first 16
degrees that the intake port is open, the exhaust port is also open.
(This is the overlap period) Since there is a great deal of exhaust
back pressure, a puff of high pressure exhaust gasses will squirt up
into the intake tract. This of course will create another high pressure
wave which will also travel towards rotor #2.
Not necessarily Paul. In many cases the intake pressure is higher
during the overlap period. See the chart below. this is from the
same 1984 SAE paper mentioned before.
I cannot distinguish intake from exhaust pressure in this picture.
Is there any way to fix this?
Paul Yaw
That is about the best I can do with the zerox copy of the
SAE paper I had to work with. Perhaps buy the paper?
Paul Lamar
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______________________________________________________
Date: Sat, 30 Jan 1999 21:30:46 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Turbos?
Archie Frangoudis wrote:
I read all commentary regarding Wankels, but see very little regarding
turbocharged aircraft applications.
Being a racing engine builder, I am aware of the trade-offs, but the end
result is positive.
Comments?
Thanks, Archie
Turbo's are great but they cost more. You need a big intercooler and
Inconel turbines and exhaust manifolds. You will also need some
effective knock sensors.
If you want to go real fast up high turbo's are the way to go.
Don't forget the oxygen.
Paul Lamar
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______________________________________________________
Date: Mon, 25 Jan 1999 09:31:45 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Alternator side mount.
Below is a drawing of a suggested alternator mount.
The problem with the stock mount is; it makes the distance
from the e-shaft to the top of the engine too long
so the engine does not fit in a lot of cowls.
This also reduces the said dimension to less than that
from the e-shaft to the tips of the spark plugs
for those thinking of running the engine tilted
over 90 degrees. AKA "plugs up".
Paul Lamar
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______________________________________________________
Date: Mon, 25 Jan 1999 10:41:25 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Used engine dealers in Japan
If anybody is going to Japan I got this list out of a
Japanes Trade Org. publication.
If you have time check out some of these companies for prices
on used late model two and three rotor engines.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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______________________________________________________
Date: Mon, 25 Jan 1999 11:17:55 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Torque pulses in rotary engines verse piston engines.
Phil Williamson wrote:
Paul wrote:
One good thing about a two rotor rotary. No torque reversals.
Paul,
For those of us with less gray matter (speaking only for myself :-) ) would
you explain torque reversal?
I started shopping around in the junkyards for a 13b to play with today.
What would be a decent price I should look for? I'm looking for something to
play with first.
Phil
A four cylinder four cycle piston engine like a O-360 Lyco stops
and backs up twice per rev. That is why they are so hard on props.
The two rotor rotary engine torque on the other hand never goes
negative. the more you know about this engine the more wonderful it
becomes :-)
See the chart below. torqvar2.jpg
Less than $1G
Paul Lamar
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______________________________________________________
Date: Mon, 25 Jan 1999 16:00:01 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Determining the tube loads in motor mounts.
Make a scale drawing of the motor mount. Top view
and side view.
Step 1. If the tubes are tilted in when looking down from
the top of the motor mount rotate them so they are parallel
with the airplane center line.
The side view of the motor mount should then reflect the
true length of the tubes. We are just going to determine
the loads in the two critical tubes.
Step 2. Multiply the distance out from the firewall to
the rubber mount times 900 pounds or half the load from
the engine during a six G pull up. Divide that number
by the distance between the upper firewall mount and the
lower firewall mount. Draw arrows on the side view that
are to scale. In other words if the load is 930 # the arrow
should be 9.30 inches long. Use a machinist scale marked off
in 1/100 of an inch. Notice the bottom tube pushes in on the
fire wall and the upper tube pulls out of the firewall.
Notice also that the firewall pushes and pulls back :-).
Step 3. We will do the bottom tube first. Move the arrow
out to the end of the tube and draw a right triangle.
The length of the diagonal line is the compressive load
in the tube. In this case it is 974 pounds. Usually this is
the most critical tube due to a phenomena called buckling.
We will talk about that in the next message. The length of
the short vertical line is the vertical load on the fire
wall where this tube is bolted to. In this case it is 270
pounds.
Step 4. Move the arrow out to the end of the upper tube. Draw
another right triangle. Again the length of the diagonal
line is the tensile load in the uppper tube. In this case
it is 1123 pounds. The length of the vertical line is
the vertical load on the firwall imparted by this tube.
in this case 630 pounds. Note that 630 pounds and 270
pound equals 900 pounds.
I may have made some errors here so if you guys discover
them I am sure you will let me know about it in no uncertain
terms.
Paul Lamar
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______________________________________________________
Date: Mon, 25 Jan 1999 16:31:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil Pan heat exchanger.
Paul-attached are the photos of the oil cooler I constructed on my oil
pan.Sorry about the delay as I ran into a bad health problem but am up
and running again.The weight of the oil cooler without the pan weight is
5.1 lbs.
thanks for now.
Bill Martin
bill@laguna-01.laguna.com.mx
Bill, is this the pan with the convential oil cooler inside
or is it a classic plate and tube oil/pan heat exchanger?
Bill also sent some pictures of a very interesting PSRU
design. When he tells us more about it I will upload
some more of his pictures.
Paul
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______________________________________________________
Date: Mon, 25 Jan 1999 16:31:15 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil Pan heat exchanger.
Paul-attached are the photos of the oil cooler I constructed on my oil
pan.Sorry about the delay as I ran into a bad health problem but am up
and running again.The weight of the oil cooler without the pan weight is
5.1 lbs.
thanks for now.
Bill Martin
bill@laguna-01.laguna.com.mx
Bill, is this the pan with the convential oil cooler inside
or is it a classic plate and tube oil/pan heat exchanger?
Bill also sent some pictures of a very interesting PSRU
design. When he tells us more about it I will upload
some more of his pictures.
Paul
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______________________________________________________
Date: Mon, 25 Jan 1999 23:03:48 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 12A dyno run chart.
Paul Yaw wrote:
Paul wrote:
Jeff Spitzer wrote:
Paul Lamar wrote:
BTW Paul Yaw, That is way too broad of a torque and HP
curve can you peak it up some for aircraft use :-)
Paul Lamar
And herein lies one beautiful thing about rotaries: Flat torque! That's
nothing, Ive seen truly flat torque curves on peripheral port engines that
span 1500 RPM+.
Jeff Spitzer
Hey there,
Here's the funny part! I spend a great deal of time trying to build
broad torque curves for race and street engines. While this engine met
its goal of 180 hp at or below 6500 rpm, the powerband was extremely
narrow. So narrow in fact that I considered it to be useless for a
street engine. I understand that a broad torque curve does nothing for
an aircraft engine. Just for the hell of it, I am sending another
graph. This is a stock 12A with an upgraded street exhaust system, and a
stock carburetor that I modify for street use. I have overlayed this
against the original post. You will surely get a kick out of this! I
understand that this doesn't help the aircraft crowd, but it sure
illustrates why the rotary regularly outruns higher horsepowered
vehicles on the race track. This relatively stock setup in a 2450lb.
1st. gen. RX-7 will wax a late model Ford Mustang. I PROMISE, no more
auto related posts after this!
Paul Yaw
In electronics there is a quality of tuned circuit called Q. You need
to up your Q for aircraft use Paul Yaw :-) Usually in electronics
that means higher peaks.12ACARB2.gif
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
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Date: Mon, 25 Jan 1999 23:15:44 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Oil Pan heat exchanger. & A.M.W. PSRU.
Bill Martin wrote:
Paul,
The oil cooler in the pictures is a sheet metal pan welded over the existing
oil pan to make a chamber about 3/8" in depth with an inlet on one end and
exit on the other.It is pinned in the center to preclude expansion.
The p.s.r.u. was purchased from a.m.w..It has a 3" offset- flywheel of 8"
diameter and an electric srarter.The gear box is straight cut gears rated at
200h.p. It is a nice design with a 2.36 x 1 ratio.As it turns out the starter
is too small to turn the engine adequently.It also comes with a rubber isolater
built into the end of the gearbox.I purchased it direct frow a.m.w. for around
$750 for the box-$500 for the flywheel and rubber isolater. I haven't found a
solution to the starter yet as the length is very short
Bill Martin.
Got a phone number or address for A.M.W Bill? I am sure others on here
would be interested. What kind of airplane is that?
I like your alternator mount. The intake manifold and throttle body
came from where or what?
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
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Date: Thu, 28 Jan 1999 02:16:49 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: Tube Loads
Bill Freeman wrote:
Paul,
Haven't really had any time to go over the tube load
stuff, looks great at a glance. Will look it over.
I have a executable Basic program which I use in my
high-school outreach seminar each summer. It will
give you member loads for 2D truss structures which are
statically determinate and is super easy to use.
Not really good for 3d geometry, but if the out of plane
dimension (Z) is small, it will be close. You should use
a big factor of safety in a motor mount anyway. Can send
an executable if there is interest. Basically just a nice
*no frills* automation of the pretty simple sum of forces/sum of
moments hand method. What is easy to one person may
be very difficult to another.
One comment. Once you know the force that the tube
will have to support (along its axis), you can calculate
the stress in the tube (which is the design limit) from:
stress = force/area where the area is the
cross sectional area of the tube. So calc the area for
the outside diameter circle
area = PI * r * r or 3.1416 * outside radius squared
then subtract the area of the inside diameter circle,
same equation, but use the inner radius.
You want to keep the tube stress below the yield of
normalized 4130 chrome-moly steel which is about
66,000 psi. I would suggest a 10 G landing as the design
point for the engine mount. Air loads do not control
this part of the airframe.
If the stress is too high, use a thicker wall
or larger diameter tube to increae the area which will
reduce the stress. This is all there is to it for a
tube in tension. NOT SO SIMPLE for a tube in
compression since it will possibly fail due to buckling.
Take a plastic soda straw and pull on it as hard as you can
with your two hands. Can't break it, can you?
Now push on the ends with your thumbs - pretty easy
to crumple it up, huh? This is buckling, which is
a lateral (sideways) instability in a long skinny member
under compression. Long skinny structural members
can fail in buckling WAY below the yield stress tensile load.
The simplest thing to do about buckling is to use a
relatively large diameter tube to give a stronger
lateral stiffness. You can go look in std eng tables,
or if there is enough interest I'll do a short ' how to'
on basic buckling calcs. But, if you use a realtively
large diameter tube and decrease the wall thickness
to keep the cross sectional area in bounds i.e. not
too heavy, you will be more buckle resistant. Also,
a center brace, even with a *very* small brace tube, will
dramatically increase the buckling resistance, because
it cuts the effective length of the tube in half. Remember,
buckling only happens in tubes in compression.
Bill
Well done Bill. Thanks for doing this. I was going to
get around to this any day now.
I would like to have that program if you can attach it.
BTW the bible for this sort of thing is Analysis & Design of
Flight Vehicle Structures by E.F. Bruhn et. al.
Tri State Offset Company 817 Main Street
Cincinnati Ohio 45202 Published in January 1965.
I am sure Dick VanG keeps a copy along side his
drawing table or computer. I paid $14.75 for my
copy 30 years ago but I'll bet it is well over
$100 now. Well worth it however. Plenty of buckling
tables for both 4130 and aluminum tubing both round
and streamline. See the one below. bucktube.jpg
There is also a very good chapter
on aircraft loads with lots of worked examples.
The book reflects the distillation of 65 years
of experience with aircraft structures.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
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Date: Thu, 28 Jan 1999 08:51:22 -0800
From: Paul <rotaryeng@earthlink.net>
To: z <rotaryeng@earthlink.net>
Subject: 12A Dyno Chart & BSFC
Paul Yaw wrote:
Paul wrote:
Bill Freeman wrote:
Paul,
Did you note the BSFC number of 0.58 on the dyno
chart. Yikes! This could almost be a turbine.
Bill
It is not far off an aircooled aircraft engine at full power.
Fortunately it gets a lot better at cruise as Tracy has found
you can run a rotary at 100 degrees lean of peak unlike
an aircooled aircraft engine.
You can expect a slightly better BSFC with a stock 13B, as opposed to a
stock 12A which is what you saw on the last post. (The low powered
engine) The stock 12A exhaust port is so restrictive, (58 cfm at 25" of
water pressure drop, as opposed to about 98 cfm for the 13B!) that the
pumping losses during the exhaust cycle are HUGE. On a stock 13B, with
an air fuel ratio in the mid to high 13's (peak power mixture) you could
expect about .52-.53 at peak power, and .49-.51 at peak torque. This of
course is with a full power mixture. I have never tried to lean one out
on the dyno, so I can't make any claims about a lean cruise mixture.
Paul Yaw
The enclosed chart shows the heat balance of a rotary engine at low
power settings.
Note:
1. There is very little loss of power with a mixture of 17.5:1
2. The rapid decrease in unburned fuel with leaner mixtures.
This suggest that a turbo compound arrangement would recover
the remaining heat lost in the exhaust. A turbo compound is where
a geared exhaust turbine is used to feed waste energy in the exhaust
back into the e-shaft for useful additional power out without
an increase in fuel consumption. The Wright R3350 turbo compound
engines were able to power a Connie from LA to London in 1955
non-stop. The R3350's BSFC was 0.36 to 0.38.
I don't think we are anywhere near seeing the full beauty
and potential of the Wankel type rotary engine. There is much
more development to be done.
Paul Lamar
The Aircraft Rotary Engine Newsletter. Powered by Linux.
http://home.earthlink.net/~rotaryeng/ http://www.linux.org
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