Hi Paul,

 I have a BD5 that started life with a 650cc Hirth 2706 EFI engine.
Short story, the
 vibration was tearing it apart, no one could solve it, 20 flight
hours and had to put
 it on the shelf.
 Installed a RotMax 650 cc single rotor carbureted engine. Standard BD
drive system,
 modified intakes, two CDI ignitions, MSD coil splitter to one plug,
electric coolant
 pump.
 Engine cooling is fine, fan used only on the ground on hot days. It
has more power
 than the Hirth and is swinging a higher pitch prop.
 So far it all works except the exhaust system. The first one (first
pic) was 304ss,
 this was my first time around the block with a Wankel. The muffler
failed but it
 missed the prop so the landing was just a little noisy.
 Went to 321ss, same configuration, working but worried about the 1800
deg exhaust
 temp. I would like to put it inside and out the bottom, but again the
temp. Also try
 to get the noise down a little bit.
 Pic's 159 and 163 are the last config it flew with. Pic's 160 and
9652 is the inside
 setup that I am cautious of
 What do you think, any suggestions?

 Regards,
 George

 Wow a Rotamax wankel. How many engines did they sell?
 You did a better job than the Rotamax factory George.
 A good candidate for one of our coaxial mufflers on the side of the
fuse.

 It looks like you already have parts of it. The inner pipe with all
the holes.
 I'll send some pictures of the coax muffler with the next message.

 What is the takeoff RPM? Fuel burn?

 Paul Lamar

A rotary powered BD-5 is one my dreams....LOVE it! Btw- doesn't a
wankel powered BD-5 currently hold the BD-5 speed record?
-Dan

This could be your record holder,
http://www.airliners.net/photo/Bede-BD-5B/1060866/L/&sid=8719fa92aebb794ade55cdb85f461f97

Erik

No visible means of cooling 326 HP.

Small world. David Lednicer is the guy that turned me on the Kuchemann &
Weber book Aerodynamics of Propulsion.

Paul Lamar


Paul,
There is a radiator visible under the fuselage to the right of the right
main landing gear in the photo.

Moose

That looks like a scoop. The outlet appears to be below the prop shaft.

Paul Lamar