The Cessna 120-140 Association Forum

My 1946 140 has the original exhaust and heat muffs. I'm wondering whether the muffs were made from stainless steel or aluminum. If someone knows which alloy that would be icing on the cake.

They are aluminum. I expect 3003 given the amount of forming required.

They are kind of amazing pieces, really. You realize this when you try to form new ends for them and rivet them on. Very light, steel stand-offs, very light. Amazing they last as long as they do.

Still looking for a set of straight pipe heat muffs. Passed up a set; didnt know I was going to need to replace but upon further examination mine are shot.

What do people use for the external clamps on the exhaust muffs?