I just attached the flywheel to the engine I'm building to put in my 6 conversion. Its built on a Carerra 3.0 case and the flywheel is an original 914/6 flywheel. The flywheel has a Z1 mark - which I assume is supposed to be at TDC. However, when the crankshaft pulley is indicating TDC, the flywheel mark is about 20 degrees off.

Can anyone explain this?

I pulled a spark plug and verified with a probe that the crankshaft pulley indication is correct.

I'll post a picture shortly.

It's obviously broken. I'll give you $100 for it............

I ddont know squat about a six. What I do know is on some engines the TDC mark for a flywheel would line up to a referance point that isnt the same as where the TDC referance for the crank would be. The flywheel mark would get offset because you would use a port in the housing to see it. That port is offset from where the crank TDC is. So as long as the mark is there in the port the thing is at TDC. Hope that is clear as mud

That's normal, it's been 20 years since I dealt with that issue but if I recall the bolt pattern changed on the cranks. I used the Z1 front pulley at TDC and re-marked the flywheel for timing purposes.

The crank throws are different on anything beyond a 2.2 (IIRC), so the flywheel will not be indexed correctly on a 2.4 and above engine. I ran into this a few years ago when I sold a new flywheel to Ed Mayo, and he told me it was bad (marked wrong). Well they were putting it on a 2.4S engine and sometime after he sent it back and got another one they ran into the same problem, so Ed got out an old 2.0 crank and 2.4 crank and discovered the difference.

What I now do is re-mark the Z1 and timing marks before you put the engine in the car.