Sheared Off Head Exhaust Manifold Studs...

[PHT33]

Anyone else that has installed a bigger turbo on the factory manifold, without removing it and replacing all the stainless studs with mild steel ones?

Just found out the long way that the stainless studs have an operational life...

The growing and shrinking of the cast iron manifold works away at the brittle stainless items and fractures them untill complete failure. Then after a few let go (6 out of 13 for me) the exhaust pressure works at the gasket and bows through. Kinda ran like it had a mild cam at first, lol.

Everyone probably knows...but still...just a heads up for any other noobs.

[ssshonky]

even if you soaked em in lubricant / anti seize before?

[PHT33]

Yeah, its the growing and shrinking of the cast iron manifold that works away at the stainless steel stud (stainless being brittle) and it lets go by shearing off about 3mm inside the head too...heaps of fun to get out. Dont even bother getting the easy outs either, no good. Hardened steel on stainless, rounds off almost imediately.