Exhaust Manifold

[Noblescort]

Recently my rear manifold has start blowing. Having removed it, I have checked it for flatness/straightness and found it to be about 1.5mm out of true along its length. As the steel plate from which it is made is 8mm thick I suspect that this warping was caused during the welding process when the primaries were welded onto the manifold plate when it was fabricated new. I guess that once it is bolted up tight that it is pulled straight, although there will be significant tensions on at least two of the manifold nuts/studs. To eliminate this I'm having it re-faced which should stop it happening again. Has anyone else ever noticed this?

[LOONER]

Had mine done twice now, the second time I had it braced top and bottom and it hasn't blown since.

[Noblescort]

Any idea why yours went a second time. If you had it faced once, I would have expected that to have been enough.

Should I be considering bracing the manifold then? and to what?

[Adrian W]

They are made by a lacal chocolate supplier and they all crack sooner or later, the later M400 type last a little longer.

[obes]

sound like your's was one of the good ones at only 1.5mm out TBH !!

[Noblescort]

Manifold and Gear linkage all sorted now!

Thanks everyone for your help. Great to be back on the road again.

So......the next job is to decide which trackday I should attend in 2008 to find out what the car/driver is really capable of (apart from making a tt of himself!) and find out what's gonna break next! Best get the springs upgraded first!!