Head bolt tightening sequence puzzlement

[Albannach]

I'm about to start fitting the new head on my truck, head's in place but not torqued yet.

I always thought the sequence was 39Nm +90degrees +90 degrees.

My AMC Bolt instructions suggest 20Nm +40Nm -(MINUS)90degrees +40Nm +90 degrees +90 degrees.

Which is right?

[karl higgs]

I fitted an AMC head to my 96 3rd gen Surf (KZN185) approx 6 months ago; I presume you also have the AMC stretch bolts? I followed the AMC instructions exactly as you described and touch wood, to date we have covered more than 6500 trouble free miles, just remember to oil the bolt threads and make sure the holes in the block are free of dirt/ old oil etc.

[karl higgs]

Sorry, I meant to say; 'I presume you are fitting an AMC head along with AMC bolts. Also, make sure to smear plenty of fresh oil under the bolt heads. When tightening the final 90 degree, try and complete the turn in one swoop as opposed to stop start. We found a 3 foot breaker bar was perfect for the job as you can simply walk from the side to the front (90 degree) of the truck in one smooth motion, it also helps if someone can assist you by holding the socket firmly on the bolt head as you go through the tightening process, the last thing you want is a rounded off bolt head.

[Albannach]

Yep, AMC head kit from RT.

I'll do as it says in the AMC instructions, it amounts to much the same thing as 39-90-90, I'm just wondering which is actually the best method and what the minus 90 actually achieves.

As for lubricating the threads, I've never been a massive fan of that. The bolts are lightly lubricated anyway, why would I need more?

[tonupteabag]

Mine was torqued to the factory service manual and has been fine upto now, i also oiled both the bolt threads (two drops 3 in 1) and just under the bolt head, i only used enough to form a very light smear up the threads, and under the bolt head just to stop any friction building through the torque procedure.

[Mr_Inter]

Yep, AMC head kit from RT.

I'll do as it says in the AMC instructions, it amounts to much the same thing as 39-90-90, I'm just wondering which is actually the best method and what the minus 90 actually achieves.

As for lubricating the threads, I've never been a massive fan of that. The bolts are lightly lubricated anyway, why would I need more?

Albannach, if it ammounts to the same thing why did you ask in the first place, just torque the damn thing down its not rocket science, dry threads or oiled threads the choice is yours, its you money at the end of the day, you asked for advice, but you obviously seem to know better.

[NiftyNev]

Waiting for

Nev

[Albannach]

Albannach, if it ammounts to the same thing why did you ask in the first place, just torque the damn thing down its not rocket science, dry threads or oiled threads the choice is yours, its you money at the end of the day, you asked for advice, but you obviously seem to know better.

In future, read my posts thoroughly, understand what I'm actually saying or asking and respond accordingly. Otherwise fcuk off.