cracked manifolds to weld or not to weld ?.

[coolchris]

I have 2 cracked stainless steel manifolds on a noble m12.The original manifolds I must have had welded up 2 or 3 times to only give up and go for stainless steel ones in the end.Bit gutted as now these ones have cracked there about 3 years old and I was given the impression stainless steel ones would hold up to the heat and vibration.Now will it be a false economy just welding up or am I just best biting the bullet(£750 each) and buying new but using a different manufacturer in the hope they last the course ?.

Cheers

Chris

[Boosted LS1]

Stainless manifolds are rubbish if you have a turbo. They flex and heat cycle before cracking. If you replace them i wouldn't mind having a look at your old ones if that's possible.

[coolchris]

I don't know then if I'm just best going to the original manifolds that are mild steel not stainless ?

[E-bmw]

As above stainless doesn't respond well to heat cycling, I would go back to oe or see if you can find someone who can do better.

[stevieturbo]

If made correctly and there are no undue loadings placed on them and they are properly made, stainless will be fine.

And for those who wrap them...that always leads to premature failure.

[chammyman]

do you have any turbo supports?

Decent support will stop them from cracking as quickly.

[stevieturbo]

chammyman said:

do you have any turbo supports?

Decent support will stop them from cracking as quickly.

Support, good quality material, allowing room for expansion etc.

Do it right and it'll last a very long time

[Evoluzione]

stevieturbo said:

chammyman said:

do you have any turbo supports?

Decent support will stop them from cracking as quickly.

Support, good quality material, allowing room for expansion etc.

Do it right and it'll last a very long time

^^ This. Heavy thickwall tube seems to do the job and also expansion slots in the mounting face, slip joints on the merge collector too.

[chuntington101]

Chris, there are manifolds that are available that have proven to stand up to a lot of abuse. Try the noble section. Think you can even get Inconnel manifolds be there are very expensive.

[coolchris]

My car is at a well known noble specialist so I will find out from them what my best options are they don't recommend having them welded though