Author Topic: Cylinder Head nut Torque Sequence and Re-torque Sequence and Process  (Read 198 times)

Offline John Gervais

I've just found something interesting, and perhaps it's not a big deal, but I'm wondering if there's a difference...

What I've noticed, is that my workshop Haynes manual has a different cylinder headnut torque sequence than the old workshop manuals have. 

I'm also wondering 'what' is the best way that I should re-torque my recently re-installed cylinder head.  Should I use the installation sequence or the removal sequence for re-torqueing? 

Loosen 1/4 turn and re-torque then move to the next sequential nut? 

I hope these pictures make sense:
- Pave the Bay -

Offline MiniDave

Re: Cylinder Head nut Torque Sequence and Re-torque Sequence and Process
« Reply #1 on: October 24, 2021, 05:49:26 PM »
John, the top tightening sequence you posted is how I've always done it - and I've paid little to no attention to how I take them off - in fact I use an impact wrench to remove the nuts!

and yes, on re-torque - back 1/4 turn then see how far it goes past that on the way back - if any.

BTW, I now do the first re-torque at 140* of temperature after first start up.....taught to me by Kent Prather of Prather racing - I used to always let them cool off first before retorquing but he says torque it,  fire it up, get it up to 140* and re-torque it immediately - then check the valve clearances again, then go ahead and run it.

I've never had one fail using either method.....
« Last Edit: October 24, 2021, 05:53:19 PM by MiniDave »
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Offline John Gervais

Re: Cylinder Head nut Torque Sequence and Re-torque Sequence and Process
« Reply #2 on: October 24, 2021, 06:11:00 PM »
Thanks Dave - Just to be clear, what sequence do you use for the re-torque?  1-2-3?   or 9-8-7?
« Last Edit: October 24, 2021, 06:12:56 PM by John Gervais »
- Pave the Bay -

Offline MiniDave

Re: Cylinder Head nut Torque Sequence and Re-torque Sequence and Process
« Reply #3 on: October 24, 2021, 06:29:11 PM »
123, same as the first time
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

Offline John Gervais

Re: Cylinder Head nut Torque Sequence and Re-torque Sequence and Process
« Reply #4 on: October 24, 2021, 06:39:07 PM »
Cool - I'll drive it back up to the garage tomorrow and take care of it as it cools down - it's too late to try 'first start-up', I took it fishing yesterday.  (didn't catch anything either, 'cept for cold feet...)

Thanks for helping! 
- Pave the Bay -