The International Cessna® 170 Association Forum forum

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!)

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

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

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

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

One of the Major Issues with multiple STC’s and modifications to “original” airplanes…. is how the various mods and alteration “Inter-Act” …or influence the other…as well as the original design. It can resemble adding a Band-Aid over an existing bandage…with insidious complications…or unanticipated problems…..and (perhaps) loss of safety-nets and function. (the “fine print” of every STC cautions about this and reminds us that the Owner is responsible for determining such things.)

One of the Major Issues with multiple STC’s and modifications to “original” airplanes…. is how the various mods and alteration “Inter-Act” …or influence the other…as well as the original design. It can resemble adding a Band-Aid over an existing bandage…with insidious complications…or unanticipated problems…..and (perhaps) loss of safety-nets and function. (the “fine print” of every STC cautions about this and reminds us that the Owner is responsible for determining such things.)

One of the Major Issues with multiple STC’s and modifications to “original” airplanes…. is how the various mods and alteration “Inter-Act” …or influence the other…as well as the original design. It can resemble adding a Band-Aid over an existing bandage…with insidious complications…or unanticipated problems…..and (perhaps) loss of safety-nets and function. (the “fine print” of every STC cautions about this and reminds us that the Owner is responsible for determining such things.)

Wally might want to refile the 337 forms for the FA Dodge seats and the Javelin tank — it appears the FAA misplaced them. (One could argue that the installation of the Javelin tank only requires a logbook entry as it is listed in the TCDS). Brendon, take a look at the pictures in this thread . It appears you would need to insure the back end of the Cessna tracks which the LakeVue seats mount to don’t chaff the bottom of the Javelin tank. The other issue may be the how the seatbelts attach in the center of the floor at the station 108 bulkhead. This attach point is where the original seat attached to the floor. The Javelin tank has a tunnel to clear this seat attach arm. It looks to me that you may have to fabricate a cable extension to clear the front face of the tank along with some sort of fairlead on the front of the tank to prevent the cable from rubbing the edge of the tank cutout. IMG_3892.jpeg

Wally might want to refile the 337 forms for the FA Dodge seats and the Javelin tank — it appears the FAA misplaced them. (One could argue that the installation of the Javelin tank only requires a logbook entry as it is listed in the TCDS). Brendon, take a look at the pictures in this thread . It appears you would need to insure the back end of the Cessna tracks which the LakeVue seats mount to don’t chaff the bottom of the Javelin tank. The other issue may be the how the seatbelts attach in the center of the floor at the station 108 bulkhead. This attach point is where the original seat attached to the floor. The Javelin tank has a tunnel to clear this seat attach arm. It looks to me that you may have to fabricate a cable extension to clear the front face of the tank along with some sort of fairlead on the front of the tank to prevent the cable from rubbing the edge of the tank cutout. IMG_3892.jpeg

Wally might want to refile the 337 forms for the FA Dodge seats and the Javelin tank — it appears the FAA misplaced them. (One could argue that the installation of the Javelin tank only requires a logbook entry as it is listed in the TCDS). Brendon, take a look at the pictures in this thread . It appears you would need to insure the back end of the Cessna tracks which the LakeVue seats mount to don’t chaff the bottom of the Javelin tank. The other issue may be the how the seatbelts attach in the center of the floor at the station 108 bulkhead. This attach point is where the original seat attached to the floor. The Javelin tank has a tunnel to clear this seat attach arm. It looks to me that you may have to fabricate a cable extension to clear the front face of the tank along with some sort of fairlead on the front of the tank to prevent the cable from rubbing the edge of the tank cutout. IMG_3892.jpeg

Thank you! I appreciate the assist! If the Atlee-Dodge fit but not the LakeVue i will purchase a set of those and sell the LakeVue. Would he be able to share any info in that direction? You’ll have to ask him at Lakevue. (Denny)