3W 106QS keeps blowing out canisters.
 

Anyone know what might be going on.
I have had to get 3 new canisters from 3W because my 106QS keeps blowing out the back.

The canisters are the Pefa MS size. They sound and run great, but after 20 or so flights one of them
seems to blow out the back in a perfect circle.

Should I lengthen the headers to move the exhaust wave forward in the can.?
If so, how should I lengthen it.?

Here is a pic.

Cheers,
wayne

RE: 3W 106QS keeps blowing out canisters.
 

You are running a very high exhaust gas temperature. This softens the aluminum.
Try opening the needles a bit more, and provide ample cooling for the cans.

RE: 3W 106QS keeps blowing out canisters.
 

Are you running the headers the length they came, or have you cut them at all?

RE: 3W 106QS keeps blowing out canisters.
 

The headers are the original length from 3W.

wayne

RE: 3W 106QS keeps blowing out canisters.
 

what are your engine temps?

RE: 3W 106QS keeps blowing out canisters.
 

alum burns at 800d carbon fiber burns at 3000d I would switch to cf they are much lighter and nothing ratles or comes loose or burns out. they are only slightly more money but will last forever.

RE: 3W 106QS keeps blowing out canisters.
 

Bollocks!
The carbon fibre may stand up to those high temperatures, but the resin that holds the fibres together won't, unless you have the fibres in a ceramic matrix. (I take it that the "d" means °F)

RE: 3W 106QS keeps blowing out canisters.
 

Could it be that they are being blown out, not burned out? Is the mixture set a little rich, and do you hear the engine "popping" when you close the throttle?

RE: 3W 106QS keeps blowing out canisters.
 

Strange, but I have had several Pefa's that weren't put together right and the ends came off, had to weld them up. They should have stuck with the rivets like the old ones. Not saying that's the problem, but I find it hard to believe that it could blow the end off, maybe, but I doubt it. You could try a set of MTW's and see what happens.

Tom

RE: 3W 106QS keeps blowing out canisters.
 

I may be wrong but my experience tells me that a richer setting causes the muffler to run hotter. This being because the gas mix takes more time to burn completely and reaches the canister before being completely burnt.

Only a guess...