Head nut retorquing before first fire up

chancecasey · 04-20-2006, 09:00 AM

(3.6L)

A couple of weeks ago when torquing down my head nuts, I noticed that my arm was hitting the angle-o-meter and screwing up the 90 degrees I was supposed to turn.

I loosened and retorqued that one but I have this nagging feeling maybe I overtorqued some of the others without noticing, before I discovered my poor technique with this fancy-shmancy angle thingy. I've noticed when I ignore that feeling bad things tend to happen.

Even though it's been a couple of weeks now, can I just loosen all of them 90 degrees in the proper sequence, then loosen them completely again in the right sequence, then re-do everything in the proper sequences/stages?

I guess my concern is, have I already stretched the studs (new style 993 dark-coated steel), or has the red paste loctite already set, or something else that would make this a bad idea?

-Chance

ischmitz · ischmitz's Garage

I am far from an expert but here is what I would do:

Losen the nuts just so that you can get the proper torque reading with the torque wrench when you tighten them again. I would do this one at a time. Don't loosen them all the way. The last thing you want to happen is the Loctite seal breaking since this would be a recipe for leaks. The 574 has cured and hardened already.

Finally, do the 90 degree angle thingy again. I assume the bumping of the angle meter resulted in some slight overtorque. Chances are that you didn't permanentely damage the head studs before unless you have gone more like 180 degrees instead of the 90 degrees specified.

Good luck,
Ingo

chancecasey · 04-20-2006, 10:22 AM

You are correct, the most I could have overtorqued would be an additional 30 degrees or so. I guess my concern is whether or not even just the "correct" torque stretches the studs in a manner in which I can't go back and untorque/retorque. If not, and untorquing/retorquing is "ok", it's a question of method.

So are you thinking maybe I should do them one at a time (untorque then retorque), as opposed to untorquing the entire set, then retorquing the entire set?

cstreit · cstreit's Garage

Ingo,

Unless he used 574 on the cylinder bases untorqueing the heads shouldn't cause any leaks...

I'd probably do them one at a time starting from the outside in...

chancecasey · 04-20-2006, 10:59 AM

Nothing but the green o-ring at the cylinder bases - which I understand can get damaged in some circumstances but I must admit I did not understand the circumstances in which they might be damaged, without using the special tool (which i don't have).

I'm wondering if just untorquing then retorquing one nut at a time would be ok. My cam towers are toqued on, seems just undoing/redoing one nut at a time would be OK - but then again things often aren't what they seem to me

ischmitz · ischmitz's Garage

Chris, you are right of course. Brainfart on my side. I was thinking of the cam towers. - but then it seems he has them already on at this point.

BTW chancecasey, the o-ring damge you are talking about is most likely referring to the case through-bolt ones. They can get nicked by the treads of the bolts if you are not careful. The special tool can be the cap of a ball pen. The cylinder base o-rings don't require any special tool as far as I remember.

cheers,
Ingo

Eagledriver · 04-20-2006, 08:29 PM

Your plan of one at a time would probably be ok but I don't like to do things like that. I think it would be better to do your plan of backing all the nuts off gradually and retorquing gradually like you did the first time. There is no problem with stretching of the studs or with the locktite. There is no downside to a do over IMO.

-Andy