With a rash of loss of power episodes, and with the lack of a definite cause, and with a common thread being that they had a Hushpower muffler, I'm thinking of either or both of these options- rip the guts out of my current hushpower muffler, or design and build a muffler that is the same dimensions as the Hushpower. It needs to have a 2" inlet be about 18" long, and be no wider than 4 1/2 inches in diameter. I'm thinking of ordering or making  2) 2 inch to  4 inch transitions made from .065 321 stainless, with a center section that is cylindrical. I want something that is not going to have it's guts blow out and obstruct the exhaust flow and kill power. It should also attenuate the exhaust note to some degree.

When I last checked my Hushpower, I took it off and it rattled like a baby rattle. I used a flexible camera and both inlet and outlet cones were intact. Still, this muffler is the thing that makes me most nervous about my installation.

Any ideas for the internal design of a muffler that is the same rough dimensions as my hushpower, but is somewhat failure tolerant?

I have one of those cylindrical SS mufflers made in Canada, I forget the name of the manufacturer, but it is cylindrical and about 24 inches long. It has angle  pieces welded across the cylinder part in a spiral pattern.  I might just cut it and shorten it to fit.

Thanks,
Brian Trubee

Is Boeing surplus still up there? If you can get some inconel that would be a way
to go. .065" 321 SS is pretty good. I would design it in two pieces and bolt them
together with 1/4 inch SS bolts. That way you can take it apart from time to inspect it.

Paul Lamar