Nismo280zEd Posted March 6, 2006 Share Posted March 6, 2006 I was under the impression that head studs shouldn't be used more than twice if that as when you torque them they pull, so re-using them puts them at risk for snapping. Did I remember this correctly? If so where can i find a set that isn't ARP I don't have 100$ bucks to spend on them. -Ed Quote Link to comment Share on other sites More sharing options...
Dave88SS Posted March 6, 2006 Share Posted March 6, 2006 I know you can't re-use stretch bolts. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted March 6, 2006 Share Posted March 6, 2006 Err.. i hope you remembered it incorrectly! I don't see why a stud would be any different to a bolt? I've never heard of people throwing away bolts after 2 uses. If you don't have $100 to spend on ARP studs, keep the standard bolts. Retap the block to minimise the binding of the bolt in the thread, and use a good quality moly-based lubricant. Last time I used head bolts I overtorqued them to around 75 ft/lb. Dave Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 7, 2006 Author Share Posted March 7, 2006 my block doesn't need retaping i used molly on them when i rebuilt the head about 1 1/2 years ago, but the head has only seen like maybe 2k miles since then. The difference between a stud and a bolt is they way they tighten. Head studs are designed to stretch when torqued that is what holds them in the head so they don't back off along with the washer. Conventional bolts are designed to stretch, they use the nut combined with a lock washer to stay tight. Quote Link to comment Share on other sites More sharing options...
zguy36 Posted March 7, 2006 Share Posted March 7, 2006 All bolts stretch when they are tightened. The difference is that less force is lost in a stud than a bolt. The steel can only handle to much force transmitted through it, so if some of that force is lost due to friction (threads in the block compared to threads on the nut), then that translates to less clamping force. This is the advantage of studs over bolts. There is less threads to lose force in comparing the nut to threads in the block. Also, with studs, the torque is not transfered to the stud when it is tightened and the stud only stretches. With a bolt, the bolt is twisted along with stretched translating again to less clamping force transmitted to your parts. A bolt or stud is only not reusable when it has been torqued many times, or it is permanently stretched. Some bolts are designed to yield when tightened to get a more consistent clamping force. This is not the case with the datsun bolts or studs. They are usually the type that say, torque to XX then twist XX degrees past. Quote Link to comment Share on other sites More sharing options...
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