Re: Valve clearances DECREASE when engine cold?

Posted by Troy Taylor On 2017/9/11 14:39:08

Yes, they will....

Having rebuild 5 of the pre-war engines 28-32, The valve clearance gets wider when the engine is hot. Everything in the engine expands with heat, so as the engine heats up the distance from the cam to the rockers increases.

The factory spec should be considered the minimum and there is no good reason to ever set them tighter, you could easily damage the engine.

Intake .0025 Cold and .004 Hot, Exhaust .004 Cold, .006 Hot.

It is important to insure your HOT adjustments are correct, a little time consuming, sometimes a pain in the butt, but important non the less.