Player0

Hi,

I'm using head studs 944-101-197-01 for the 89 944 with the 2.7L head. This is a 944S2 3.0L block. I'm not getting enough thread engagement. These are 150mm give or take.

I have a set of the S2 studs which I assume are for the 16V head, but they're about 20mm longer. That's about the length I may need here.

Real dumb question. I have the studs bottomed out. Before I change over to the longer studs, did I install these studs wrong? I ask because I'm almost positive these are the correct studs for this job. Yet, too short in this block.

944crazy

The studs should not be bottomed out. The proper way to install them is to the height above deck as recommended in the workshop manual.

That said, they may still be too short. Hopefully someone else will chime in with the correct stud length and installation height for the 2.7 head and 3L block.

Tom M'Guinn

Install those studs to about 72mm above the deck and you should be good to go. No need to bottom them out, as long as you have plenty of thread engagement in the block at 72mm.

Player0

Well, even if back the studs out by a couple turns each, I'm not sure they'd be 72mm above the deck. That'd be backing them out by 6-8 turns. That would probably work, but doesn't seem right to me.

Is it generally a good idea to not bottom them out then? I wonder why, won't they bottom out when torqued anyway?

Tom M'Guinn

You need to put something on the stud to keep it from turning, so they won't bottom out. See thread from earlier this week....

https://rennlist.com/forums/944-turb...-question.html

Player0

Yeah, Michael Mount did my machining so he instructed the use of the high pressure lube.

V2Rocket

Because then you are pushing the stud into the bottom of the hole and you might get your torque value but the gasket won't be compressed.

The studs shouldn't move much if at all when torquing the nuts - torque on the nut stretches the stud in place, it doesn't go like a bolt would.

Player0

Nothing worse than someone who doesn't update the thread. So I tried one of the S2 bolts but it was fantastically too long. Back to these 2.7L bolts. I had to back each out a little more than 4 turns to get the full 72mm sticking out. They work fine now.

I hope this isn't a significant reduction in threads. Sounds like it should be fine. But really 10mm longer would be more idea.

Tom M'Guinn

Did it look like this? BTDT...

Player0

No, a little shorter than that, but just long enough that the nuts wouldn't bottom out

Humboldtgrin

Yes the 2.7/2.5 head studs are different then the DOHC head studs.

V2Rocket

Tom you could just "double nut" it for safety...

Humboldtgrin

https://www.ebay.com/itm/221728669046
https://www.ebay.com/itm/221667503119

Tom M'Guinn

I tried that, but the threads were too high up. So I just used ten washers on each one.