Advice sought - exhaust cracking

[huntaero]

Hi Nev have a good look inside the exhaust tube fwd of the external crack, maybe the tube has cracked inside the heat muff.

[fairchild1934]

Annealing ferrous metals uses a very slow cooling -- and nonferrous often uses a heat and quench. Im not sure which category 300 series SS falls into---- I will try googleing on that topic----

[fairchild1934]

looking at the part-- my first thought on the possible movement was like a speaker cone. The doughnut ring attempting to pivot at the junction with the center pipe. Maybe being driven from the center pipe---- so the center pipe and the outer sleeve are out of phase with each other. But it could be twisting too I guess.

[Nev]

IMG_1554.jpg This picture shows what the internals of the exhaust look like. Disregard the finger pointing, it was after the #4 cylinder issue so the exhaust was in several pieces. However you can see the cone shaped baffle that normally resides inside the heat muff. The part that has now cracked two more times since then is to the left of my wristwatch where the pipe joins to the heat muff.