Valve guide clearance?

How tight should valve guides be? I'm redoing a set of '55 Cadillac heads with almost zero miles on them since new guides because of a crack in the head. I've cleaned them up and are trying to put them back together and the valves are tight. Do the guides open up when the engine worms up or will they start to stick?

Thanks Gary

 

Common valve stem clearances are: .001-003 for intake, .002-.004 for exhaust. The valves should move freely in the guides. Make sure everything is clean when you assemble the head.

Who put the guides in? Valve guides are pressed into the heads and then finished reamed to the recommended size.

Bob

 

Make sure that the end of the stems are trued up so that they don't have any edges sticking out to hang up on the guides. Dressed right they will have a barely noticable bevel on the edge of the tip.

 

That might be part of the problem. Once I get them in they seem to glide smoothly.

 

Please don't make them too tight! They will stick and cause lots of problems. They should feel free in your hand but not sloppy. better loose than tight.

as said earlier .0015 to .003 is OK but I don't imagine you have a gauge to check this.

 

If you drove in new guides, they must be reamed to a specific size. If this was not done, they will be way tight.

 

Some Specs:

 

Thanks
Pretty close clearance half to one thousands clearance. Seems like if they move smoothly it's probably alright.