The Cessna 120-140 Association Forum

Hello All,

Does anyone happen to have a set of exhaust muffs for the straight pipes? The bottom end of my left one just cracked off where the clamp holds it to the pipe, so I'm looking for something to fly on while I have a new set fabbed up. Thank you, Karl 310.614.two fivesixeight

I do have a set of the original " pancake " style exhaust stacks. Let me know if some part of these will work for you.
Bill

I have a set somewhere. I don't remember if they are serviceable, but I can check. Are you calling the pilot's side left?

If the end literally broke off, that might be a pretty easy fix. How about posting a picture?

Yes pilot side.

Seems like these are 0.032. Working with 0.04 5052 is kind of challenging. Are these things 3003 from the factory?

It wont upload a 3mb photo. Try these:

https://www.dropbox.com/scl/fi/29j59cgc ... sm9dc&dl=0

https://www.dropbox.com/scl/fi/1aoscte5 ... xdrfo&dl=0

I guess I will either rivet this up or do the same thing with 032 material to match the parent material a bit more closely.

Not sure if anyone cares but I decided to use 032 and shored up the other side also. If anyone knows what rivets to use on 0.32 material please let me know. Is there a squeezer that will pinch both sides at once? Seems like there should be. Thanks in advance. Going to rivet these and get them back on the plane asap.

Look at AC43.13-1b for information on how to pick rivet sizes.

Some observations:

You could probably get away with 3/32" diameter rivets since it's not structural, but most folks would probably go for 1/8" diameter.

The rule of thumb for length is the material you're joining (.032x2) plus 1.5 times the rivet diameter. (.032x2 = .125x1.5) (1/16 + 3/16 = 1/4, I think)

There are squeezers with long noses that could probably get in there and work, but they'd be pretty easy to drive with a riveter and bucking bar, too.

Thanks. The 3/32 tended to fall over in the material, so 1/8 is a better choice for anyone doing this repair.