Thread count of Porsche studs?

[dhopkins]

My rebuilding project has been held up by about two weeks for want of the correct stud used to bolt together the engine and transmission on my 69S. Three of the studs are the same but the fourth one is longer because it goes where the starter is mounted. This longer one is what I am lacking. The stud is a M10 type but has to be about 110mm in length. I haven't been able to find this size at any of the usual sources such as Pelican, etc so I was thinking of just ordering from a non-Porsche source like "Bolt Depot." They don't have metric studs but do have metric bolts. To order properly you have to specify the thread count. A standard thread count is 1.5mm. Is this correct for these studs? Does anybody know a source for the extra long stud required for the hole next to the starter? I have been working on this rebuild for 16 months and am ready to be finished already!

Don
________________________________________
1969 911S
1976 914 2.0
1981 911SC

[andyjboy]

In '69 Porsche used a bolt for the top starter motor fixing.

Part number: 900 067 078 02

It was an M10 x 150mm allen-headed bolt (ie the head of this bolt is like the barrel nuts for the heat exchangers)

[bob tilton]

Call Jim at EASY - 510 653 EASY or 415 653 EASY - I forget the area code. He should have it.

[dhopkins]

150mm is way too long; it needs to be about 110mm.

[andyjboy]

Sorry, the part I quoted before was for the Sportomatic model.

Correct part number is:

900 067 074 02

M10 x 110mm allen-headed bolt

[Grady Clay]

Don,

If you want to change to a stud (like ’72->) use 900.061.192.02 (M10x102, DIN 835-8.8 verz.). That uses an M10 thread, 8 mm internal hex wrench nut at the starter. With four studs it is much easier to mount the transmission to the engine without stressing the input shaft.

Any of the engines can benefit from threaded inserts in the case (Helicoil, Time Serts, Casesavers). This is particularly important with magnesium cases and when using bolts.

Best,
Grady