Ryan Thompson

I have read several threads on this site regarding Angle Torquing heads. I have a 86' 928 S 32V.

I was using a 3/8 Snap On torque wrench, in which I could see the torque value as I was doing my angles. It goes up to 100 ft lbs, so wan't worried about maxing out the wrench.

I replaced washers and sanded the bottoms down on a flat survace with 240 wetsand paper.
I oiled the studs and in doing so oiled the washer, thus allowing some to spin on the 2nd 90.

I did the following
20nm (15 ft lbs)
90 degree
90 degree
90 degree

I only ended up at 50 ft lbs on some of my studs. So......I torqued them all even to 71 ft lbs.

I fear this was a mistake and I need to start over and have to by another head gasket for that side. I have only done 1 so far. Other head still working on changing valve stem seals and lapping valves.

Is my gasket toast? What should I do?

davek9

Did you use New Studs?
If not some may have necked, thus the low torque reading on some.
I use new studs and only do two 90, not three, IIRC it has something to do with newer material on the new studs.

As you have not heat cycled the gasket it could be OK, I'd just buy another to be safe considering the Labor to replace it if it leaks.

GregBBRD

Those studs have yielded and are now junk. New studs and new gasket now required.

I've written volumes on this subject. Check the history.

Justin Tyme

So do you need to change studs/bolts every time you take the heads off ?

That's an expensive proposition if it's the case.

skpyle

https://rennlist.com/forums/928-foru...ead-studs.html


Its a long read. Get a bag of pretzels and a beer. Lots of good information, though.

Justin Tyme

It's War and Peace.

So, to save time and space..... if the studs are not pretty well brand new (only used once) then replace them.
Don't buy/use the ARP ones.
Buy genuine Porsche ones or the ones from that Simard guy.
Torque them down using the angle method, 2x90 degrees.
Clean out the threaded block holes using a thread chaser/cleaner NOT trying to cut a new thread with a tap/die.

Mrmerlin

if you clean out the block holes use an old stud with 3 flutes cut into the tip about 4 threads deep ,
dont use any other tool to do this.
Use a mapp gas torch to heat the block around each stud do one at a time heat the area then remove the stud.
NOTE measure the studs now so they can be set to the same height

davek9

Always replace the S3 Studs or S4 Bolts w/ new, else chance having one or more neck during the process and then you be buying gaskets and starting over.
I've heard tell some reuse them (maybe 16v OK as they are torque only) but for me not 32v as they use the clamp by stretch method as do most newer engines.
This is just my experience,and I've only done several 32v and no 16v over the years, so take that for what its worth (nothing