"Couple of other things, why are 220,000psi studs so much more special than 200k ones? Cuz ARP has the 200k ones in stock, and most likely it'd be more economical than having a custom set made."
I just went to the Summit online catalog and found this ad for the 225 slant six studs:
"Pro series cylinder head studs from ARP are cold-forged to ensure molecular integrity. They are heat-treated prior to thread rolling and machining and are rated at a whopping 220,000 psi. ARP Pro series kits are also available with 12-point nuts, and all kits come complete with hardened parallel washers for an even load distribution and accurate torque readings."
Part number #142-491 $101.95. I think we paid more than that... so, apparently, prices have come down. :cheers:
I called Tom Wolfe, and you are 100% keyrect about his utilizing a custom Wiseco piston with lower compression when used with K-1 rods, which he also uses. You were also right about the measured compression ratio on his engine with those pistons; he said it was about 8:1. So, I was in error on his setup. I asked him about my 9:1 pistons and he said he thought it should be fine for my race-only application since I was not going to attempt to run it on pump gas (93 octane,) mixing that gas 50/50 with higher octane (110?) race gas, watching my A/F ratio closely at 11.5:1 under boost, and limiting my spark advance to 18 degrees (locked plate.) I hope he's right... he usually is.
I was apparently wrong about Ryan Peterson't pistons too; they are reportedly TRW's, but I don't know what compression ratio they are, or whether they are the old-design "Speed Pro TRW" pistons. Surely, they are,but I was under the impression that those forged pistons had been deleted from the TRW catalog years ago, and were no longer available.... so, I dunno; maybe I'll call Summit and ask them.
I apologize for all the bad information; I'll try to be more accurate in the future. Thanks for the correction(s.:oops:
