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I plan to put one in a Midget Mustang.
Thanks,
Jeff
That is a real packaging challenge.
A 2 rotor with cooling system would be a lot to shoe horn everything in.
A p-port one rotor might be a better idea.
Do you have a 3D dwg program?
Paul Lamar
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Hi Paul,
I agree it would be tight. I like the HP/weight ratio of the rotary.
So far the project is still in the planning stages. I know very little
about the rotary engines. I think the firewall width is about the same
as a rotary. I plan to move the cooling aft of the firewall.
I will be researching rotary engines more. The p port engine uses a
different intake port?
No drawing program yet......
Jeff
A P51 type cooling system would help. You will need some structural
changes
to the aft fuselage. If you scan that part of the dwgs and email them
to me I will see what can be done.
The 56 inch prop diameter is unusual. That implies a higher prop RPM so
perhaps you could save the weight and expense of a gear box and run the
all aluminum P-port Mazda at 3500 RPM direct drive. The intake runners
would
have to be about 36 inches long to get the torque peak down to 3000 RPM
but that could be done by wrapping them up and over the engine. An
aircraft
up draft carb would help or if you are bucks up a Motec EFI.
I always enjoy a design challenge so I will do a 3D for you. HP would
be about 200 X 3500 divided by 5252 or 133. Engine weight would be about
150 pounds less cooling system.
In the mean time read this article on the web site.
http://www.rotaryeng.net/fund-of-intake.html
Here are some picture of an RV4 to give you an idea of how
things ft in a narrow airplane.
Paul Lamar
Hi Paul,
Thanks! I like the EFI route The main use of the plane is to fly to
San Jose (about 300 miles) as fast as possible. MY wife is in San Jose
and I am in Victorville. So claim they cruise above 230 MPH with a
IO-360. I also like the narrowed nose that a rotary would allow. Plus
the sounds from a flat 4 big bore engine reminds me of a tractor.....
All of your help, energy, and efforts are greatly appreciated! Thanks
for the article!
Jeff
Paul/others,
What has been the experience with direct-drive engines in aviation
use? Does the stock "front" bearing enough for prop loads, or have
folks found it necessary to include an add-on bearing/hub to take those
loads and to reduce resultant thrust/bending loads on the e-shaft?
The layouts and stresses are very different from a rotary, but in
the VW and Corvair engine world add-on bearings and prop-hubs are common.
133 HP (approx) at 3500 RPM, even up to 200 lbs total would be very
acceptable for many aircraft, especially if it allows skipping the
cost/complexity of a PSRU. Static/low airspeed thrust would take a hit,
but that, too, might be fine for some designs.
Mark
The front main bearing (rear in the car) is fine for prop loads. The
problem is thrust loads.
Perry Mick destroyed the front thrust bearing in 650 hours with direct
drive ducted fan. It can be redesigned by doubling up on the needle
bearings. Minor mod.
The problem is the power to weight ratio is bad in direct drive at 3500
RPM unless you spend big bucks
on aluminum end housings. The 16X would be better if it every
appears. The 56 inch prop is also
rather inefficient at low speeds.
Jeff, it would be cheaper to build or buy an RV4.
Paul Lamar
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