Head Studs?

[nhockett]

I see head studs listed as mods on more serious setups. Are these longer bolts that hold the head to the block? If so when should they be upgraded? Can these bolts be replaced one at a time with the t-belt remaining in tact and not replacing the head gasket? I assume this is for high boost applications. If I'm way off let me know. Thanks

[rambur]

Most people replace their head studs when performing any mod that requires removal of the head (i.e. bottom end rebuild, head gasket replacement, etc). 7-bolt factory head studs are torque-to-yield, which means they stretch when tightened and cannot be resued. 6-bolt studs CAN be reused, but it's not advised. Most people choose to go with ARP studs (as I have). They work great and can be reused. Much stronger than stock and they go for ~$90/set. And, no, it's not possible to do them one at a time... you'd have to remove the head and do them all at once. I wouldn't advise new studs unless you were taking the head off for some reason. It's too much work to make it worth-while otherwise.

[nhockett]

I'm having my engine rebuilt by a machine shop (1g 6 bolt that has taken over 4 wks since I dropped it off) and it sounds like these bolts (probably not ARP) should be replaced by the machinist. I will ask. Sounds like it would be complete bull$hit if he didn't replace them. Thanks

[rambur]

6 bolt head studs CAN be reused, as I mentioned, but yes, I'd recommend getting them replaced if you can afford the extra money for it. It's a good investment, IMO.

Mark

[kjewer1]

Originally Posted by rambur

Most people replace their head studs when performing any mod that requires removal of the head (i.e. bottom end rebuild, head gasket replacement, etc). 7-bolt factory head studs are torque-to-yield, which means they stretch when tightened and cannot be resued. 6-bolt studs CAN be reused, but it's not advised. Most people choose to go with ARP studs (as I have). They work great and can be reused. Much stronger than stock and they go for ~$90/set. And, no, it's not possible to do them one at a time... you'd have to remove the head and do them all at once. I wouldn't advise new studs unless you were taking the head off for some reason. It's too much work to make it worth-while otherwise.

Right on the money, good post

Additionally, be absolutely positive of two things if you have them install the ARP studs. Clean out all of the threads with a tap (M12x1.5 I believe for 1g, M11xsomething for 2g) before installing the studs. They MUST be able to go ALL the way in by hand. Two, use ONLY ARP MOLY LUBE. It can be done with oil, and I've done it before, but dont take the chance. Spend the 3 bucks, or use the packet that SHOULD come with your studs (sometimes they dont). I can show you a handful of blown HGs that were the direct result of not following the two recomendations above. Read this:

http://www.racingknowledge.org/topic...earchTerms=arp

I ran a USED mitsu metal gasket that I mention in that thread and it was still good when I tore the motor down for other reasons.

Hope this helps. Good luck.