Head Nut Torque

[DHDamo]

Hi all, looking to do a maintenance tweak of head nuts over the weekend and have a dilemma. I'm juggling 2 manuals which have different torque settings suggested. I'm down the the sequence and slacken, oil and tighten setup but:

Autobooks manual states 52-54 ft lb (at stage 3)
Haynes manual states 64 ft lb (at stage 3)

That seems like a huge difference. The Haynes manual is more specific for the different engine sizes (I've quoted 2l) but seems like a LOT more torque.

What have the experienced ones used and what should I go for? It's not a rebuild, just a maintenance tweak.

Cheers,

DB

[brook308]

Victor Reinz instructions

[DHDamo]

Thanks George. Is that assuming it a reinz gasket? Maybe it's not a reinz, does anybody else even make them?

[DHDamo]

90nm is more than both other manuals 

The previously stated 64 lbt ft is 87nm according to Haynes

[brook308]

Hi Damo,
Do you know the history of the gasket?
If all is ok, and it's not due a retorque due to new fittment then I'd leave it alone.
A retorque of a unknown age/type of gasket might just bring on a failure.
I personally torque to greater than 90nm but thats due to boost.

[DHDamo]

I had a tiny bit of oil in the coolant overflow last weekend at lakeside (only during 1 run it seemed). Figured either the gasket is dead or a retighten will help. I tightened when I first got the car as part of first service but only to the 54 ft lb as I only had the one manual then and that's what it states. I've probably done 8 track days and a few thousand k's total since then so figured it's due and I'm hoping for a miracle.

[Neil Choi]

Back off half a turn and retorque to 65 ft/lb from stone cold first thing in the morning.  Should retorque after every couple hard outings, if not too much.  But I could be wrong!!!

[brook308]

I had a tiny bit of oil in the coolant overflow last weekend at lakeside (only during 1 run it seemed). Figured either the gasket is dead or a retighten will help. I tightened when I first got the car as part of first service but only to the 54 ft lb as I only had the one manual then and that's what it states. I've probably done 8 track days and a few thousand k's total since then so figured it's due and I'm hoping for a miracle.

Worth a try, 90nm shouldn't do any harm.
Worst case scenario it's off with the head, bit of a shave whilst it's off for some more compression a new gasket and you're back in action 😄

[DHDamo]

Yeah figured it's worth a try. Have a new gasket if it doesn't fix as well as some different cams I'd like to try if it comes to that.

[DHDamo]

Back off half a turn and retorque to 65 ft/lb from stone cold first thing in the morning.  Should retorque after every couple hard outings, if not too much.  But I could be wrong!!!

Is it not worth backing off a bit more to add some oil to threads/washer?

[Neil Choi]

I don't.  Suppose you can if you want to.

[Mick A]

i wouldn't touch it. you will likely cause a bigger problem! It will disturb what oil seal you have left

[GTVeloce]

I had a similar problem recently with a little oil in coolant. I torqued to 60 ft lb and it improved for a very short while, then it came back. So I torqued to 70 ft lb and it worked well. Then two months later I had a hole in my head gasket and am currently in the process of head removal.

Interestingly I had the oil in the coolant for some months before I got around to trying the first attempt. It didn't seem to get any worse but I did need to keep an eye on my coolant as I would leak a little and needed regular top ups which probably backs up Choderboy's advice.

[DHDamo]

Ok , cheers for the tips guys. Have been watching closely and haven't lost any coolant in a long while. Have re-torqued as per the manual so will just have to see how we go (had got that far before choderboy said to leave it  ) I have a new head gasket so if it comes to that so be it.

[MD]

Correct head bolt tension starts with a CALIBRATED torque wrench. After 30years in the toolbox, I just had my Warren & Brown wrench calibrated. Cost me $140 but then you know why the head bolt snapped if it does..