Head Torque with - Dry Nuts or Oiled?
Turbo Mini Forums

Have searched the forum for a consensus on the question of oiled or dry nuts before head torquing.

Before researching I assumed that tighter (More clamping pressure) would be better than looser so I would have used the higher torque figure in Haynes 55 ft lbs on oiled nuts. However I believe that oiling the nuts effectively is worth 5 ft lbs ie lubricated nuts turn easier so the clamping force will be higher at a lower figure.

Also I now appreciate that correct compression of the firing rings in the head gasket is vital


The concensus I think I have found is:

Dry 50 ft lbs Oiled 55 ft lbs

Whats your view?

Also

Opinion differs as to how to warm the head through before checking/final torquing. I thinks Haynes says 10 minutes coolant in. Other people have said 1 minutes running NO COOLANT

What the general feeling here!

I have a standard ERA Turbo head to tighten down.

i would do them oiled at 55ftlbs im certain thats the book figure

and to warm it through ive always gone for a gentle drive but for 20 or so minutes

Edited by Brett on 20th Apr, 2011.

Yes i moved to the darkside

Instagram @jdm_brett

Ricsdad - you are corerct in that oiling the threads/underface chanegs the compression in a joint through the applied torque. Generally you lube the threads/underface for consistency of clamping load - not to increase the load on the joint. You lose over 50% of the applied torque through friction, if you can reduce this figure its a lot easier to control and obtain better efficiency and a more consistent clamp load.

If you apply more torque to a joint with lube than you would normally do on a dry joint the nyou are stretching the bolt more and bringing it closer to its yielding point. The nyou need to look at things like surface deforamtion through increased clamp load etc - I will write an article on this as its a fascinating subject.

my recomendation would be 45-50 lb/ft with ARP lube on thread/under head, building up progressively and leave sittign at 40lb/ft for at least 30mins before final application.

JK

If Carling made Mini engines
it would probably be like this one!

i also run a tap through the nuts and a die over the studs while off the engine just to make sure the threads are clean and straight, if re using old studs and nuts

Speeding is like masturbating, everyone does it, but not all of us film it and put it on the internet

[quote=fab,8th Oct, 2010]fuck off

Thank you everyone and johnK in particular - I shall follow your advice!

and dont be tempted to overtighten, the fire rings dont like it. :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.