Over on the engine section the question was asked about a muffler for a small engine with 360 degree exhaust ports. This is very close to what a Cox engine muffler does. I remember seeing and reading on here or maybe on Stuka Stunt about some one that came up with a home made muffler for Cox engines based on using bicycle inner tubes. I've done a basic search on the 1/2A section and the engine section with no results, but I don't think I'm imagining this. I need to post on the Cox Engine Forum also and will do that tonight, This might have been 10 years ago or longer. I just remember thinking that the concept was pretty sound, and the originator of it said it was pretty effective and very little, if any , power loss. I've just slept too many times since then to remember details!
Type at you later,
Dan