For all you engine builders/tuners out there I have a question. At what power level do you think ARP head studs become a necessity?
interested in hearing some opinions on this. there was such a huge shitfest on nasioc built motor forum about it a long time ago. everyone had an opinion either way. problem is that was very little data to back anything up
Well the main question is at what hp level do these motors experience some sort of head lift? I don't know that there is a definitive answer out there yet as these motors are relatively young. Wish I could add more too it, but I don't think there is really a good solid answer at this point. Definitely good insurance though!
eh, sometimes I really hate this line of thinking with car modifications. a lot of people install the ARPs incorrectly and have failed headgaskets anyway. they aren't like OEM bolts
That is my concern. I have done plenty of engines with stock head bolts and never had an issue. Hell the ones in my car now have been used at least twice. One side may be on its third pass. The engine I am putting together now I want to build with a larger safety margin than the previous one. I feel that anything north of 500 the ARP's are a better option than the stockers.
With my experinces with engine builds and the of studs verses bolts is that studs of coarse as u know are made of a high grade steel that does not stretch. I have always used them on heavy nitrous applications (200-1000Hp systems) in combo with copper head gaskets with wire. I also use them in Heavy boost (25-40psi) with copper and wires. Studs are good insurance policy if u can go back and re-touqe after a couple of heat cycles with the use of a factory type gasket. Clarification on the previous statement is because the stock bolts are tourqe to yeild bolts that stretch and keep constant and even clamping force on the gasket. A factory style bolt will allow the head to lift, but it would take some serious boost and detenation to do so. Studs are strong and do not stretch, they are not forgiving of a bad tune were factory bolts might let a head gasket go before the crown of a piston from detonation. This is just from what my experiances have been, hopefully it answers some questions. I may have repeated myself or something, it took me like a day to write this G.D. thing.
All steel will yield (stretch) ARP or not Its the material they use and the smallest cross section (weakest) So if the bolt is coarse thread then its more likely to stretch more than a fine thread section . if you have the same amount of holes and torqued down the same it will have the same holddown distribution. The quality of material or improvement of surface quality is what you pay the extra for $
I don't think I would want stock bolts in it north of 500 but thats just an opinion there is no fact to back it up