steveL

has anyone had head studs pull on a car that already has inserts in the case? car is a 77 911s with 7R case. engine doesn't seem to have been apart and repaired before. with inserts already in the case, what is the proper repair so that hopefully it doesn't happen again? cylinder 2 came loose and damaged the base of the head due to compression sealing ring breaking apart. head studs on that cylinder are noticeably higher than the rest of the studs. thanks for any advise.
steve

Jeff Curtis

Steve, we did have a 2.7 engine here locally that had timeserts in the case in prep for the larger Dilivar head studs...several of them pulled.

Wound up the machine shop used the wrong size drill/tap for the timeserts and consequently the threads pulled out, quite the tradgedy.

The machine shop paid for a used case and inserted the timeserts properly. That engine has been going for about 6-7 years now!

As for your engine, depends on the damage caused when the stud pulled, I guess it's possible to upsize the timesert and go from there...but certainly there is reason to be concerned about the other inserts!

geo.aigel

If done right the time certs should be bullet proof. The fatigued magnesium is cut out and the timesert goes into fresh material with a much larger area to distribute forces to.

So, Jeff is correct, something is fishy with the timecerts. It should not happen. Are you positive they pulled and didn't just simply break?

Good Luck!

George

steveL

they don't seem broken, or even physically loose in the case. head nuts weren't even loose at time of dissasembly. seems very odd. Is it heard of that for whatever reason the studs "stretched"????
steve