Ten Studs Per Head, But Which?

plurbo · 10-15-2025, 02:52 PM

Hi - New join here. Thanks for all the help already on my top end rebuild. I need some help identifying the correct studs to buy, as I've discarded the old studs and can't make sense of the way our host has listed the specs for the new ones. Or maybe it's just the product photos are wrong...

Each cylinder head on an '84 3.2L has ten studs in it. Looking back at my notes from when I extracted them:

2 intake studs (protruding from the head by 3.2cm)
2 exhaust studs (protruding 3cm)
4 tall camshaft housing studs (protruduing 4.9cm)
2 short camshaft housing studs (protruding 2cm)

When I search the parts numbers, the studs that come up do not look like the right lengths. Anyone with experience replacing these studs have the right links or sources?

gled49 · 10-15-2025, 04:09 PM

Be careful Porsche only published the stud length showing, not the total length of the stud.

plurbo · 10-15-2025, 06:07 PM

I had a feeling that's what was going on. Because it looks like some other manufacturers post the full length of their same versions. So I'm not crazy!

draw · 10-15-2025, 06:19 PM

See my post below…

Quote:

Originally Posted by draw

I believe that most, if not all, of the studs in the case are DIN 835 standard. This means that the "tap" end is 2x the diameter of the stud. For example, an M8 stud has a tap end of 16mm. This is the end that is screwed in to the case. The other end is the nominal length of the stud.

You can identify the stud from the parts catalog...

Pos #4 on the parts diagram is an M8 x 35mm stud.

So, the height of this stud in this position is 35mm.

Some words of caution...First, there are mistakes in the parts catalog, so be careful. Second, most of the studs you can buy are not DIN 835 and will not match exactly. Meaning, that the nominal length of a stud might be 35mm, but you may only be able to find it in 36mm. Third, a lot of these motors have been apart a few times by now and may not have the correct studs in them to use as a reference. I crosschecked all of mine against the parts catalog.

I measured and took pics of every stud in my case before I removed them. If you post a pic of the missing stud, and I might be able to help you.