I looked into that! I believe they were to short :-( Below is a quote from a PM I shot a few guys on here about head studs.... Let me know your thoughts if anyone has some!!!
Quote:
Well here is what I have found....
Option 1: Go to bigger studs! ARP makes 10x1.25 studs that are 163mm long, this would require machining which I am not to happy about but at the same time the amount of clamping force a 10mm studs can provide over a 8mm stud is pretty great. You would have to machine all case bolts to fit the 10x1.25 threads.... which would require a complete tear down of the engine as well as boring the head and block holes to 11mm to fit the 10mm studs. These studs are sold in sets of 10 for about 100 bucks - ARP # 208-4301 Now the threads have 1.3" on one side and 1.0" on the other or 33mm and 25.4mm which I think would work out perfect because you only need 24mm inside the cases so that 33mm of thread might work out perfect! Food for thought about this way.....
Option 2 - Not 100% fond of but cheap enough to try it! I found a company that makes M8x1.25 studs that are 150mm long that have 35mm of threads on each side... ARP said the studs should be 155mm long using a 3mm washer under the ARP nuts.... well ARP does not have 3mm thick washers available but they do have ones a little more than half the thickness at 1.6mm What I am hoping is is that we could use these studs and have just enough to have the nuts be flush with the top side of the stud. This to me is taking a chance of it working or not but the studs are very inexpensive at about $25 for 6 studs and then another $40-$50 in ARP nuts and washers.
So heres the difference in strength that is making me consider stepping the cases up to 10mm over 8mm.
ARP 10mm tensile strength - 200,000psi
TECO 8mm tensile strength - 120,000psi
ARP 10mm torque spec - 60 FT LBS!!!!
ARP 8mm nuts - 25ft lbs :-/
Now the stock 8mm bolts only get 23ft lbs so so stying with a 8mm stud may not be the best for a boosted situation but it could be more affordable and easier to accomplish.
I personally would love to run the 10mm studs but I'm really not in the mood for a engine tear down... yet again if I pop a head gasket in the process I'll be shooting myself in the foot anyways. The 8mm studs I think would work but ... 1. they are not as strong as the ARP chromoly and 2 they are 5mm to short from what ARP is telling me the studs should be. I'd rather have 8mm of threads sticking out of the top then a nut half on which I dont think will happen but until I psychically put one in the engine we wont know for sure.
P.S. the 8mm bolts do not have the nice 3mm broach but the 10mm ARP's do. you can always double nut the stud and torque it that way or they make tools that will thread on and then lock to the stud to tighten...
Let me know yours thoughts!
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