Avcon muffler 15006

[Cessna170B52]

Hello,

My first post on this forum!

I have a 1952 Cessna 170B with the Avcon SA806CE O-360 conversion. The existing muffler has developed a significant localized bulge in the outer shell on the upper right side.

There are no intact internal flame tubes. However, after looking more closely inside, there are badly deteriorated tubular remnants around the inlet openings which I suspect could be what remains of the original flame tubes. I have attached a couple of photos below.

I recently ordered a new replacement muffler, which has now arrived, and was surprised to find that it also has no flame tubes. The manufacturer tells me that the flame tubes are optional.

I had assumed that my old muffler originally had flame tubes which had deteriorated/corroded away, and I am wondering whether their eventual disappearance could have contributed to localized heating and the bulging of the outer shell. However, the internal condition is too deteriorated for me to establish with certainty what was originally there. I would therefore really like to determine what the original Avcon design specified.

Does anyone have a copy of Avcon drawing 15006, Sheet 1, Rev. B?

The Members Area contains a fantastic amount of Avcon material, including several drawings relating to the SA806CE STC, but unfortunately I haven't been able to find this particular drawing.

Avcon drawing 17000 and Kit Parts List 17025 identify the 15006-2 muffler for SA806CE, so I am particularly interested in seeing the original 15006 drawing and establishing whether the internal flame tubes were part of that configuration.

I would also be very interested to hear from anyone who has opened up, repaired or overhauled an original Avcon 15006/15006-2 muffler and knows what the original internal arrangement looked like.

Any information, photos or old documentation would be greatly appreciated!

Fredrik

[DaveF]

Here are the documents in the library. Doesn't look like we have a 15006. There isn't one in my paperwork either.
https://forum.cessna170.org/forums/view ... 259#p83259

My muffler, which according to the logs is original, does have flame tubes, or what's left of them. I don't know if they used to connect side to side, but they don't now.

IMG_8414.jpeg

[n2582d]

Here Signia Aerospace/Hartzell/AWI says, “Internal baffler (sic) or flame tube is required for muffler to be airworthy.”

[cessnut]

It's more likely that the bulging occurred as the flame tubes disintegrated, causing localized heat spots.

[GAHorn]

One problem mufflers (of all makes/models) can suffer is internal baffles that deteriorate and fall apart…. and potentially block gas-flow and exhaust exits….thereby causing loss of engine performance. There are plenty anecdotal stories on that matter, and is something an thorough inspection include, using a strong light and mirror.
Some muffler designs incorporate a “cage” to help prevent blockage.

One of our Assoc’n supporters is AWI, Aerospace Welding Inc. (they have donated many dollars in exhausts and parts to our conventions) and Charlie Feld up there is quite knowledgeable about various muffler designs and overhauls. You might call Charlie and let him know you found him thru these forums and ask his opinion and advice. His Ph is 651 379 ninety-eight 88.

Tell him George says “hi”.

(and WELCOME to the Forums!)