hey folks,

doing a top end rebuild with a a new S&S case and cylinders....picked up a pair of cometic .030 head gaskets and installed heads per cometic directions

but on the last torque spec of 42 lbs, the bolts were skipping.... i oiled the head bolt threads and under the shoulder, but still were skipping at final torque.... i suspect i probably didn't get an accurate final reading

any thoughts?.... should i be worried?

thanks!

JS

 

What do you mean by "skipping"?

 

the movement of the head bolt isn't smooth, tightening it... it jumps, like a stutter

 

Are they all doing this? Are you sure it isn't your torque wrench? Try another wrench; doesn't sound right; the bolts should reach torque unless stripped.

 

they all did it.... and how could they possibly strip?.... they threaded all the way down

the only damage i suspect would happen is that i started turning the cylinder studs, but i doubt it.... it's a new S&S case with studs already in it, and would certainly take more than 35 lbs of torque to strip them into the case, no?

i mean, i hope that's not what happened....i was pretty spot on in torquing these things, using a beam torque wrench

 

If you're wrench is clicking at 42 and that's what you mean by "skipping" then it's fine. You could leave it a few hours and recheck the 42 final, or back it off 1/8 of a turn and redo the 42 final, I have had this happen twice and never a HG failure. You followed cometic procedure and cleaned all surfaces well, don't sweat it if this is your situation.

 

i don't think it's the wrench... it's a beam torque wrench...it's not a digital one that 'clicks' when it reaches torque

i don't know....i really hope i didn't mess something up.... i followed cometic procedure exactly....did everything by the book, so i can't imagine turning the threads on the cylinder stud in the case....that would really suck since it's a brand new case

 

Does the beam wrench skip or "pause" internally when it reaches torque like others? My point is is the wrench going off when you attempt to do final torque?

 

Beam torque wrenches don't "go off" like the clicking ones to. I use and generally prefer a beam type, but I also prefer vernier calipers... It's not at all unusual to see some variations in torque as you come up to spec, but it's usually pretty smooth by the time you get there. There may be some galling under the head of the bolt which would cause that, but I'm not sure that I'd pull the heads after they're torqued down just to check. I presume that you're torquing in steps, yes?

 

yeah, i've always preferred the beam types, too... it's what my uncle always used, and he swore by them

anyway, i'm certainly not going to pull the heads....no way... i'm just going to move forward and get it in the bike....and yes, certainly torqued in steps as cometic outlined... everything was smooth up until 35lbs...beyond that, is when i got that torsion jerk

praying everything is all good...i just want to ride