Anyone know if this differs from that for a standard head gasket?

Having said that, I may not have followed standard procedure correctly as I have a small oil leak from the front corner.


I've only done 10 very gentle miles on it and apart from that all seems fine so far.

I torqued up to approx 40Nm as instructed, then reset torque wrench to 110Nm. However, when I went for the 180 degree rotation I got 110Nm at about 120 degrees, so stopped. Should I have continued round to 180 degrees regardless of torque reading? I know the head bolts are stretch units - and yes - I did fit new ones.

Thanks in advance - hoping I haven't wrecked a new gasket and bolts

 

Kurt, I am not aware that the cometics require a difference torquing procedure.

However, iirc, the 180 degree turn must be done without checking for torque.
So it's likely your head isn't clamped on tightly enough, hence the leak.

I don't know if it's ok to tighten it up, or, if you need to start from scratch now with a new gasket and bolts thoug.

The problem will be that unless you remember exactly how many degrees you turned each bolt before stopping, you won't ever be sure you did them all up correctly and not under/over tightened

 

Just found this on another post:

Remember to always tighten the bolts in the correct sequence.
The stages below DON'T refer to engine tuning stage, do every bolt up to stage 1, then every bolt up to stage 2, then stage 3

2WD
Stage 1: 20 to 25 Nm
Stage 2: 45 to 50 Nm
Stage 3: Rotate further 170 to 180 degrees using an angle gauge.

4x4
Stage 1: 45 to 50 Nm
Stage 2: Turn 170 to 190 degrees using angle gauge.
Stage 3: Check for 110 Nm.

I guess the "Check for 110Nm" means the bolts have to be at least 110Nm when tightened up, but probably will be more once done fully up.

-Did you do them in the right sequence ?
-Are you sure you head/block aren't warped ?

 

Thanks frog. I'm on a 200 block so it's the 4x4 procedure I "followed". Like you, I now read to it mean 180 degrees then check for 110Nm. All 10 bolts went round to approx 120 degrees when they hit 110Nm

I know that they were all done in the correct sequence and the block was machined flat before I started. The head was fine before it came off - it was a piston problem that lead to the rebuild, not a hg failure.

So I guess I have nothing to lose by adding another 60degrees to each bolt and monitoring the situation for now. I'm running in anyway so won't be thrashing it.

 

I would say that difference in angles and torque between the 2 engines is down to head design and not block mate.....if your using a 2wd head i'd stick with that spec.

 

Fair point, however, when you look at the "procedure", I am not sure the end result is that much different, in both cases, the bolts get torqued up to 45/60Nm, then turned 180 degrees.

 

Buy new bolts and when its stone cold, do them again properly mate although technically the headgaskets seal is probably now compromised.

 

wel i have just bought new cometic head gaskit annew 200 block and stud and nut kit and inside the stud and nut kit it says torque to 80 to 120 ftlbs and no more is this right?

 

Not sure about this but I would have expected the stud/nuts NOT to be 'stretch' like the bolts, so procedure and torque settings may well differ. My Cometic gasket set certainly had no mention of any procedure changes.

I've added 60 degrees to my bolts at stone cold. The oil seep has stopped - wondering now if it may have been there from before I torqued the head down at all.

I take Stu's point about the 'proper' way forward - I'll continue to monitor and budget for a new gasket and bolts if things go wrong!

 

i am gonna call steve scott @ A1 tommorrow to find out what he say about stud and nut kits and cometic head gaskets