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[frostbite]

Hi guys
I have a small problem

When I bought the car it was sold with a blowing manifold, I thought  a crack which can be cured with a new one but I found  a sheared stud on the mount.

I was going through the history and found that they had drilled and recut a broken stud so as the block is the same as the zlet and presumably the z20leh can the head be used as the astra can have silly power and I've not heard of there studs breaking

Secondly with the cams be the same or just swap them over?

Cheers

[05omegav6]

If you're thinking of going down the tuning route, C20let is as good a starting point as any

[frostbite]

Not tuning just using the head. My exhaust studs have been recut and sheared again so am wanting to use the turbo head for the strength

[annihilator]

it still happens on z20let's 

John.

[Marks DTM Calib]

Its not the head, its the manifold.

When ever I fit or refit one I always use a straight edge and grind the manifold face flat.

Then its fresh studs fitted to the head first and fresh nuts

[frostbite]

So what should I do?

[Nick W]

Drill out the broken stud and use whatever thread repair insert you(or your mechanic who will have done this sort of repair before) are happiest with. Helicoil is one of the common types/brand, but there are others.


Doing this to all of the stud holes is probably a good idea, and on a 2.0l will be possible with the head still fitted. A kit to do this will be about £25. Replacing the cylinder head for this problem is a complicated, time consuming and expensive 'fix'.

[frostbite]

Ok seems simpler,  should I get a second manifold to have machined flat I have noticed a curve on most of them

[minifreek]

The C-Let and Z-Let heads won't work with the X20XEV block unfortunately...

The stud that normally breaks is the stud nearest to the thermostat housing, its a very common problem and not just on the Omega's...

If you want to change cams, go for the H cams for both banks, they do produce a bit more power than the standard cams, but 1 of them will already be a H cam - which will be the exhaust...