Classic cars forum & vehicle restoration.

[Miken]

[quote="Glenn Crawford"
The feller says it makes a huge difference, adding 50% to the clamping force, which I am happy to believe, but what do other forum users think about this practice? I thought that cylinder head nuts are fitted and torqued-down dry.[/quote]


I wasn't sure either, so when I fitted the head on my A40 Devon A coup!e of Weeks ago I rang up Gosnays Engineering (Who have done work for me in the past) "Ooh, we used to do loads of them back in the 50/60's"
And he told me apply, " a bit of engine oil on the threads"
Which is what I did.

[MVPeters]

I was always taught, mostly by my grandfather, fount of all wisdom & knowledge, that no fasteners should be assembled 'dry'.
So a light cleaning of nuts & bolts, followed by a drop of 3-in-1 was his, & now mine, rule.
I'm not sure if torque wrenches or Loctite existed then, so 'tight' & 'very tight' were the guidelines.
_________________
Mike - MVPeters at comcast.net
2002 Mini Cooper 'S'

[ukdave2002]

[petelang]

I'm no expert but good engineers have told me, under no circumstances to oil the thread section on head studs. However it may be he means to lubricate the non threaded part to allow the head to slide down onto the block properly.
But do also check the stud has thread below the top face or the nut, whilst achieving the torque, may not actually be clamping the head. In such case you may need a washer under the nut.
Peter

[Ray White]

I would say if you prefer to lightly lubricate threads then fine...but please don't then rely on "dry" torque wrench figures - they differ considerably.!!

[Glenn Crawford]

All points noted. I carried out a test to see whether enough torque was being applied by the head nuts (with oil) to squish the copper gasket even a little tiny bit - to give me confidence that it would seal - but it measured precisely the same after the test as before.
That being the case I have admitted defeat (which I hate to say!) and gone back to using a traditional gasket. I can't for the life of me understand how solid copper gaskets can ever work if they don't compress, but clearly they do, and they have a loyal following especially in the motorcycling world.

[Miken]