I do assembly of my H22. Yesterday I started to plastigauge main and rod bearings (ACL). I have a feeling that something is going wrong...

I hand tightened main studs as ARP stated in the instruction. They were all level when I did them all. Put bearings, plastigauge, caps and oil bridge. Nuts were tightened in a 2-step way (22, 55) in a proper order. But when I started to torque them to the final torque they had some "jumps" when it was easier to turn them. It was like the second end of the stud was screwing deeper into the block...

Is it OK? Or should I worry then? Should I tighten them stronger initially?
Any advice welcome.


Modified by pentaq at 2:23 PM 5/31/2006

 

I always put in the studs a little more than finger tight. After getting them finger tight, I take a ratchet and tighten them a few ft-lbs just to make sure they wont move.

 

I've had that feeling on head studs before.

Take an in-lb torque wrench and tighten the studs to 108in-lbs... aka 9ft lbs.

I would also recommend cleaning the threads in the block with parts cleaner and compressed air to make sure no foreign particles are in there which is not allowing you to get accurate torque readings.

That should take care of everything

 

I did so too. Just to be sure they're not loose. But when I tightened them more there was a "easier" turn on some of them. Maybe 15 degrees... more less. After that tightening was seamless.

 

I torq my main studs down to 30ftlb. You also should use a tap or thread chaser to make sure all the threads are clean. Put some oil on the threads but not to much cause it will build up at the bottom of the hole so you might not get a good seating. Even if you don't torq them to 30ftlb you need to have the holes and threads clean to get a good proper reading when torquing the caps down.

 

30 is a bit much for just the studs... I've never gone over 15. I have had a customer bring me a build b20 where the guy torqued the **** ouf ot the head studs and guess what? One of them would not come out.

Whatever works for you is good... but personally I think 30 is a bit too much just for the stud.