This is the muffler I designed a few years ago. The object was to build something that could be hidden inside a cowling.

It was originally for the .72 but seemed a bit too restrictive.

Here it is on the .62 and has not shown any problems but the engine is not fully broken in as yet.

I will report as soon as I've done some more evaluation.

Bob Z.

Bob showed me this muffler at Brodaks, it's a jewel and am hoping he or someone will start producing the things.

Maybe Pat Johnston could start making them.

Yeah but thing will dump the exhaust inside the airplane.  You got one installed on a plane.  Please show us.

Doug and Brad - good calls from both of you.

First off - the muffler can be rotated by simple loosening the large hex bolt. OR, it can be removed and flipped over such that the pipe is in front. The accompanying photos of the device mounted on a SAITO .72 cylinder should clarify.

The muffler was originally built for a .72 which was installed a very tight cowled in application. I had limited working space so I made it thin - too thin, in fact. During test running, the .72 ran slightly hot but the power was noticeably down. No such problems on the .50 or .56 - haven't run it on the .62 yet. I plan to build another version with approximately 50% more volume.

For the record, the muffler operates on the principle of radial diffusion to dissipate energy. Not a new idea as it is employed by a commercially available system called the "Super Trap" (TM), designed by Paul Moller. When I worked with Dr. Moller in the 80s, he explained the principle. Since I'm not strong in thermodynamics or compressible fluid dynamics, I was understandably lost!!!

Therefore, my muffler is more or less fabricated, not really engineered.

Bob Z.

Who knows? When I was working there, (~1986) there was lots of activity centered around the prototype - he had already started working with the rotary engines.

A number of earlier protos, electric powered, I believe, did indeed fly but I'm not sure about the Skycar. You might see if he has a website.

Bob Z.