Ryan Thompson

I am contemplating changing my head gasket while the motor is out. 86' 5.0 32V.

I am seeing some people that reuse the head studs and replace the nut and washer.

I only paid $1500 for the whole motor and the head gasket wasn't leaking. Mileage advertised was 120K.

The cost of new head studs or bolts is outrageous from what I am seeing.

Where do folks buy them and what is normal pricing?

Advice please!

outbackgeorgia

Sooooooo, you want ti fix something that is not broken?

Ryan Thompson

Just want to do all Preventative Maintenance while motor is out. Don't want to spend $1,000 on new studs or bolts. For that price it is worth installing without replacing head gaskets and rolling the dice for a while. Replacing all other gaskets and timing belt.

The old motor had around the same mileage and the head gaskets showed signs of wear. I pulled the motor apart to inspect failure. It was from torque tube pulling on flywheel grenading thrust bearing and ruining block.

skpyle

Ryan, on the S3's, the head studs are quite reusable. The nuts must be replaced. Most people reuse the washers after roughening them up with 400 grit sandpaper. The problem comes when you have a damaged stud. Meaning heavily corroded. New studs are a different alloy/metallurgy than the originals. The new studs require a different torque spec and sequence. Very unadvisable to mix new and old studs. So, if you have a bad stud, you replace them all. Lousy.
I am dealing with the head gaskets right now on the Red Witch. All the head studs on mine are in excellent condition, with zero corrosion. Only one unscrewed. It will not be a problem to reinstall it.

The only unbroken 928 head gasket is the one you just installed. 120K miles is right there in the neighborhood for good time to do the head gaskets. Be prepared for Pandora's Box, though. Once the heads are off, you really should have them done. Surface the decks and have the exhaust valve guides replaced. As well as all the valve stem seals.

Do some searching, plenty of info here on Rennlist about it.

Good Luck!

Ryan Thompson

This is very helpful. Thank you.

hacker-pschorr

Reading material
https://rennlist.com/forums/928-foru...ead-studs.html
https://rennlist.com/forums/928-foru...p-washers.html
https://rennlist.com/forums/928-foru...ead-studs.html
https://rennlist.com/forums/928-foru...placement.html
https://rennlist.com/forums/928-foru...-question.html
https://rennlist.com/forums/928-foru...ead-studs.html
https://rennlist.com/forums/928-foru...questions.html

FWIW I did not replace the studs, only the washers, when replacing the head gaskets on my 81 which was then supercharged. No issues under 20 or so PSI.

Better now before they leak since changing head gaskets on an 85/86 engine in situ is a royal pain in the butt.

I would never put a 30+ year old used engine into a car with the original head gaskets installed.

outbackgeorgia

OK, makes sense, but the slope is steep and slippery! There are a lot of old parts in that engine!

skpyle

Oh yeah. And there is no bottom. Read any of my threads...

Ryan Thompson

So you just replaced washers? not new nuts?

hacker-pschorr

Yup

linderpat

subscribed. Lots of good stuff here, and all the links in one place. We are all going down this path at some point.

SwayBar

+928!

And, if it were me, I'd replace the nuts only because comnecting rod nuts shouldn't be reused. What does the WSM recommend?

GregBBRD

Depends on what washer came on the engine, for me. A 1985 engine should have washers thst are completely ground flat on both the top and the bottom. These can be reused indefinitely. Earlier engines have washers that are stamped and not ground. They look fairly flat on the top side, but have an irregular bottom surface. I replace these washers with the ground version for more even pressure on the head.

The nuts are a one use item, according to Porsche. Especially important, for me, on early engines that came with the "thinner" nuts. Probably not a show stopper if the engine came with the updated "thick" nuts. Personally, I do not reuse any of the nuts on any version....new nuts are fairly ecconomical.

Reuse the studs, if there are no corroded ones....the old studs are better than the new replacement ones....by a huge amount. If one or two studs are corroded, try to find two used studs and replace the corroded studs with original studs.

Think carefully about the factory recommended angle torque method when tighenimg the heads. Review what Porsche recommends for a 944 engine, with the same hardware. Also review what they suggest for 928 engines with bolts.

Do whatever your brain tells you.is correct.

Mrmerlin

FWIW if you need to clean stud holes only use a old stud that you have ground three slices into the first few threads with a shop grinder
using any tap will usually destroy the close tolerance of original mfg
wirh loose fitting studs it’s easy to then have them pull out
you will then learn what a timesert is