main bolts question

[Mr Overkill]

Are the main "bolts" yeild to torque bolts


and are arp bolts needed with 300-350 hp just asking because the machine shop said i will need to align bore it with the arps


thanks

[mpgmike]

Factory main bolts are indeed torque to yield.

I would replace every single torque-to-yield bolt on even a stock rebuild. I don't trust them. They are reliable 99% of the time, but ARPs are reliable 100% of the time. As for align boring, I beg to differ with your machinist. It either needs bored (whether you use stock style bolts or ARP bolts) or it doesn't...period. I recommend ARP rod bolts, head bolts, and main bolts (in order of importance) on your rebuild.

Mike

[Mr Overkill]

i have the apr rods now

i thought it was strange that the caps would need align boring (hopefully some one can clear that up)

head bolts i Think im going with Apr studs if $$$$$$ is ok

[Stevien1]

It's just like having the rod's resized during a good rebuilt. The main bearing bores become out of round after years of stress and heat cycling. Also, the align-boring does just that- sets all the bores on the same centerline so the crankshaft is not being stressed.

Have the shop check them and perform the align-bore if needed. FWIW, I've reused main cap bolts on these motors all the time, just make sure there is no stretch!

-Chuck James

[Mr Overkill]

ok gonna have him check the bore with the standard bolts if they are off and need to be done then i will get the arp main bolts lol

[Mr P-body]

Two things that I have found with the ARP studs and bolts is 1.)They definetly show varying torq differences with different High pressure lubes and 2.) The clamping force is greater causing the bore to become out of round. This would be the reason your machinist wants to line bore the block, I personally would reccomend it. You can always have him torq #1 down with stock bolts then install and torq # 2 main with arp and have hime show you the difference with the same sunnen gauge set to spec.

-Mike