JohnKoaWood

IF you pull the head... might I suggest you considder having all 8 studs done?

ramius665

+1. Always better to do everything at once instead of waiting for things to fail.

kinglenario

yeah, that's a good recommendation. have you guys had issues with these studs just breaking off on their own without trying to remove the manifolds? i guess that's what the shop was trying to say happened but i don't know...

PEvans

I had a stud break for no obvious reason, so I guess it happens. I had to pull the head to remove it.

F18Rep

Pelican has the time certs and I think case savers too but when I had to do this on a 911, I opted for a sort of staked insert that I got from McMaster carr. Those have worked well but a couple of things: it takes a pretty big hole and its scary drilling it. You have to have enough material around the hole to support the insert. Second, the hole has to be deep enough for the tap, the tap is usually tapered which means the hole has to be deeper than the insert.

This pig is just before I tap the stakes down securing the insert.


The other thing is the nuts that we use her in Porsche land for the exhaust - steel on a steel stud in a AL head seems like a bad combination to me, although I'm maybe sensitive after pulling a 928 engine just to fix a damn stud. So anyway, I use these copper nuts from Pelican, they are cheap and don't rust up. Look for them in the 911 area of thier webstore. 944, 911 & 928 all use the same size nut (M8 x 1.25)

PS. I like inserts over heli-coil but I'm thinking inserts require a bigger hole so may not always be best...Bruce

kinglenario

thanks bruce. that's good input.