Main Bearing Studs

I have an opportunity to buy a full set of main bearing studs for a SBC Chev (2 bolt main). I emphasize that the set is used. The set has been thru at least 30 torque and release cycles (used for engine mock up, etc.).
Does any one know what the life of a quality stud (ARP, Donovan, etc.) would be?
How many stretch cycles can they go thru before they are deemed overworked or over stretched and thus, unusable?
Since I suppose the same question would apply to rod bolts (not nuts) also, would they be in the same boat?

TIA, John

 

I dont think their like torque to yield, but why not just buy a new set....just a question

 

Under $60.00 for a new set of ARP. Dont waste your time with used.

 

Thanks for the price TR, I didn't know how much they where.....I agree....NEW

 

I guess if they where dirt cheap, (free) then I'd get them for maybe a mock up motor..or something

 

Well O.K. I'll purchase a new set of studs. Ya talked me into it.

Back to my original question... How many torque cycles can a quality stud go thru before it should be replaced? Can they be handed down from one generation to the next generation or are these studs a use once and replace type of deal?

Can they go on for years doing their job, or should they be replaced with the creation of a new motor. Kinda like the situation I face now, they are used, what is their life span?

John

 

check ARP's web site and check with one of their people.......

 

putting them in your parts truck they will last a lifetime ---good for at least two in high rpm applications--- at least that is what i told myself when i reused mine

 

I just don't think they will ever give up, I'd look at the threads on the top side that hold the caps on for distortion in the thread area. I've seen them used in race motors forever. Rod bolts a far different story!

 

Steel can be cycled as long as you don't exceed the elastic limit. That means they will stretch a little and come back. If they were streched a lot and exceed the limit, they would be longer. And usually the threaded portion is what moves. Then the nut won't go past the stretch.

I'd be more concerned that the PO ran nuts on and off with an air gun and the threads are nice and loose. And prone to stripping at some point.

Main Studs are a lot less stressed than rod bolts.

Frank

 

To answer the question one would have to purchase a set of GO-NOGO gauges to check the pull on the threads

 

Normal street use and some beating on it now and then, I'd take them for free. I would splurge on new nuts though.

Bob

 

They should have the stretch data on their website, as long as they still meet their recommended stretch value they should be fine regardless how many times they have been torqued.

 

BTT for the afternoon/evening shift. Unless your at the GNRS, then enjoy the show.