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

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This would make a good poor country fighter plane for shooting down
insurgency fighters. WW I aviation history repeats itself :)

Paul Lamar

                       
There is a belly scoop just barely visible in the first pic (near landing gear strut also just visible abaft wing trailing edge), similar to a P-51 type scoop...
-Dan