If I could offer a suggestion....
....you should check the specs on that engine, and more importantly find out about
the torque/RPM range that the engine runs in. For one thing, a 15CC tuned pipe is
really big....something you may not want to hang on an airplane in any case. But
more importantly, a tuned pipe may not do a darned thing for the performance of
that engine unless you are trying to get a large increase in power via RPM.
The things is....if you have a "torque engine" (low rpm) a tuned pipe isn't going to
help very much, if at all. On the other hand, if the engine is a screamer (high rpm)
you might be able to extract some more power from it.
There are other exhaust systems that may be better for your application, like the Jett
mufflers, and the Ultra Thrust type exhausts. Again, it depends on the torque design of
the engine....what you have to start out with, and what you want to end up with.
The bottom line is, not all engines will benefit from a tuned exhaust.
FBD.
