So, I am building a 3 liter for a very low serial # first year 930. The car has been sitting for many years and its been a challenge thus far to deal with.

I knew I was in for a surprise when I stripped the ancillaries off and rolled the engine upside down on the stand and a couple of broken head studs, with their nuts fell onto the ground..

I never dreamed that EVERY head stud except one, on each side of the engine would have been broken! These did not break during disassembly! i only had to put a wrench on one nut on each side of the engine!

We've all seen these break like mad, but I've never seen this many broken on one engine. The real crazy thing is, it appears the only reason they stopped driving it was due to chain rail failure that made the bank 2 chain drag loudly inside the chain housing.

The heads were sealed tightly to the cylinders and only one of them showed signs of any combustion leakage.

The owner wanted something special, so they sent it this way, so I'll see what I can cook up :-)
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Where was that thing stored?

Do you think this was the 1st time it was taken apart to that level?

Wow! You can clearly see the studs are rusted at the break. Sheeze!

They all broke due to rust on the head nuts an studs..must have been sitting outside. Look at the tins too.

It was stored in a barn since 83.. The engine is all virgin, had original plugs and wires even.

Wow, the stuff you find with aircooled..
What a project...

These rusted after they were broken. The rust did not effect them structurally. Where they were laying in the engine they could have never found their way there unless the engine was operated this way.

These engines were horrible about breaking studs, and this was the 28th turbo off the assembly line (documented), so its a very early example.

The engine also has two bent rods, so it is my bet that someone turned the boost up and created this issue for an already weaker set up.

I split the case today and the internals are otherwise beautiful.. Its going to be a fun one to resurrect, especially considering who owns it. She's a pretty cool chick.

Jake, You are very fortunate that most of the head studs broke closer to the heads than the case. It is a real bear trying to get them out if they break flush with the case.

Yep, know all about it!
But, one of them is broken at the case, with about 1/2" of thread protruding. I am not even fooling with them, just going to send the case out to a buddy of mine from long ago who does destructive stud removal. It removes the stud completely and creates no shock to the case, or the original threads.

Some may have broke with a boost but they were already rusting. Very common cause.

The car has been sitting since 1983. Though the studs see clamping load when static, I am sure that sitting did not break these. There are no rust pits at the fracture points or any other indicators that rest played a role in the failures.

Someone along the way upped the boost till it popped then mothballed it.

Yep.

I have a 964 here right now that someone added a big turbo to. At one point in its life it was supposedly pushing over 600 hp until it broke some studs. Cylinders are so out of round I'm suprised it had any compression left at all.

Sounds like it needs Nickies :-)

That's not a bad option and we are considering it. It would need custom pistons.