Dusty Ratcliff

I was reading a thread on another site & they were talking about using grade 8 allen head bolts in place of head studs, seems they cost around $80 vs. the $400+ of a set of studs, any info on this mod.??????? thanks, Dusty

wannadiesel

Sounds worthless to me. The reason studs clamp better than bolts is the fine pitch threads at the top. You get more clamping force at a given torque because the finer thread gives you more "leverage" against the head. Changing bolts doesn't do a thing for clamping force.

Dusty Ratcliff

there was some talk about the stretching points of the threads????? I've heard of these allen bolts being used on some trucks in W.V., & running some high boost #'s(other than the trucks spoken of in the thread on the other forum) & they seem to work better than the stock bolts, maybe not as good as studs, but for light bombers, a $350 or better saving could open doors for other mods???? just a thought???? Dusty

HOHN

It's not JUST the finer thread pitch. It's the superior tensile strength of the material as well.

Think of a bolt or stud as just a really stiff spring. When you torque it, you are stretching the spring. You want to stretch the spring as far as you can (max clamping) without the spring losing it's "springiness"

The finer thread pitch translates torque better into preload because there's less thread friction.

jh