Got the cylinder head at the machine shop for a rebuild, got me thinking of placing studs for the intake manifold.

I recall that they are the same length and pitch as the exhaust studs.

The machine shop said they could 'copy' the exhaust studs, since they would be made from scratch, i would like to know, is there anything special about the exhaust studs? material, coating and so on? or just make some steel studs and forget it?

 

They are most likely an 8.8 steel stud. You could check the PET or manuals to see if they list it as 10.9. I would also guess that the exhaust studs see higher temps and more stress. You should have them plated with something like zinc.

 

Intake studs will work but there isn't a lot of clearance to put a nut on them (they hit the intake) and getting a socket on the nuts are difficult on 4 of them so you have to use a wrench.

 

I don't think with studs you can re-install the head because the studs get in the way of the headstuds and nuts. I could be wrong though. PM Eyal about this.

 

Eyal had a thread on this and as I recall the biggest argument against the studs was the potential for scraping the soft mating surface (aluminum or gasket) of the intake manifold under installation.
I also adopted the idea from Claus Groth of gluing the gaskets to the flanges of the manifold, so you know where they are.

Laust

 

I'm going to *try* to use the Saturn studs on my intake manifold when I re-assemble... has anyone with intake studs tried them there?

 

While you have your head off and some of the exhaust apart you might want to check out these threads. Offering a complete hardware kit from the head to tailpipe, when the two bolts from the wastegate to the car cost $21 buck each from pelican you can almost get the entire kit for the price of just the two bolts.

https://rennlist.com/forums/944-turbo-and-turbo-s-forum/254994-951-exhaust-hardware-list-finished.html

https://rennlist.com/forums/944-turbo-and-turbo-s-forum/259575-exhaust-hardware-orders-teaser-pic-added.html

Just a thought since you have some of it apart and are replacing some hardware.

 

I never saw any indication in PET that show the grade of steel

Previously, i used studs/nuts/washers on the intake manifold, but since i don't have studs for the exhaust manifold, i switched them around. A 1/4" drive 13mm socket with an extention worked fine, even the torque wrench worked fine. Got the kit from Zim's, and Kirk informed me that these are exactly the same as the studs for an 86 951.

I would like to get a set of these, but problem is shipping is pricey. So i would be paying ~$30 to have them shipped here alone, i should have payed more attention to that thread and planned ahead, and not to mention 7-10 days to get here (time delay). But so far, i didn't go over my budget (cylinder head, front seals, oil cooler seals, oil pressure relief valve seals, AOS seals and polishing engine parts and the various tools here and there), would like to stick to the plan

 

8.8 bolts are plenty strong for pretty much any auto application except extreme places like flywheel mounts, head bolts, suspension, etc. The intake manifold mounts are not a high stress application. 8.8 will be fine. Minimum rated tensile strength is 120,000psi.

Interesting site:

http://www.boltdepot.com/fastener-in...ade-Chart.aspx