hot or cold

[Bison]

Hello folks,
So, armed with my special exhaust tool, I have got the rear castellated nut on my project Strada to turn, the front one however isn't playing, very tight indeed. would there be any advantage if the engine/heads were warm?. Thermal expansion happens in every direction!.
I should say that the head threads have been replaced by the looks of it, and the nuts look reasonably new.
Thanks,
Alan.

[Steve Brown]

Yes, I would expect a warm engine to be easier to remove the exhaust nut. Alloy expands faster I think than the bronze so if it is turning already should be no problem.

[norbert]

To fix the nuts propperly you have to repeat tightem them up several times with a hot motor.
So it's quite clear that it will be easier to take them off the same way.

[Mepstein]

I get them hot with a torch and they come right off. If they are stubborn, I touch a piece of paraffin to the part. It wicks between the threads but doesn’t evaporate off like penetrating oil.

[norbert]

What should he hot is the head