Andrew Olson;649 wrote: They do stretch, but I believe they are something like $12 per stud, so that adds up real quick. There are many 928 motors that have re-used the head studs/bolts and are just fine. I think the key is that if you use the old studs and follow the WSM proceedure of 20Nm followed by 3, 90* turns to tighten the head, you may get inconsistent torque values. The key is you want about 66ftlbs on them. I'd follow the proceedure and then on the last 90* turn torque to 66ftlbs and be done.
I'm running with the used ones and basicly did what AO said checked for even torque as some did not feel right (stretch?).
Sooo.. if I go through a Head gasket in the near future, I'll re-do it with new heads Studs ~$400 bucks on a 32 valve, have Valve guides redone and the heads cut and ported.
This all was not in my budget as I had already spent $2,500 on the Head re-fresh and some other goodies while the eng was out. I was also burning up summer drive time.
If your not going to Boost the eng by whatever flavor you choose, your most likely going to be good to go, unless you see an issue w/ the stock studs.
Dave
