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

-- Nope, Boeing surplus has gone the way of the Dodo bird. Actually, it
exists on line, but in a much abreviated form. Not the homebuilder's Valhala
where you could lose yourself for a whole day browsing.

Brian Trubee

Paul, I had an exhaust system on a full size Dodge in 1965 that didn't have
a muffler, just a larger tailpipe with strategically placed "dents" along
most of the length. Under accelleration it sounded like an air hose. While
trying to find out how it worked I ran across a description of exhaust parts
including catalitic converters. These converters are designed to withstand
temperatures higher than the exhaust gasses since they are combustion
devices. Possibly the shells of two of them could be emptied, baffled, and
installed in tandem as a muffler.

george grimes