I have a fully built css b18 ls vtec and unfortunately the guy I bought the motor from had arp 2000’s in it and the motor is already assembled, I’m hoping to make 800 hp and I’m wondering if any of you guys know the limit of the arp 2000’s, they are torqued to spec he said, so what psi do you guys think they will start to lift the head at? 25psi?

 

A "B" Series CSS block is not rated for 800 HP... you need a true sleeved block for that level of power. ARP 2000 bolts should be associated with your connecting rods, not the head studs. Lifting the cylinder head has nothing to do with the rod bolts, although again, 800 HP is truly at the limits of what that bolt can survive. Changing to 625+ bolts requires resizing the connecting rods and may require different rod bearings. Incidentally, what connecting rods do you have ?

 

The block is rated for 800hp as quoted by Jeff at css himself, and I’m not talking about rod bolts I’m talking about head studs, arp 2000 head studs

 

Standard ARP head studs are rated for 200,000 psi tensile strength... boost pressure isn't really the benchmark and you cannot simply target that. Ignition timing, cam timing/overlap, compression (static and dynamic) all affect your maximum cylinder pressures. It will take more than 25psi of boost to make your target HP goals.

 

This is funny this thread came up.

I just noticed speedfactory sells their own headstuds now, the 4140 210,000psi rated, and they profess 800+hp.

Arp 2000 are 220,000psi rated. So based on that math, your head studs shouldn't be the weak point.

Also, I cant find B18C ARP2000 material head studs so those must be rare-ish or may be incorrect info.

In general I see ARP 8740, ARP L19, or 4piston 625+ as options; in order of strength.