The Stovebolt Site Forums The Shop Area Engine Shop '61 235 Major Water in Oil

That variance number must be put in the proper context. The only change from a hot/cold engine is the length of the valve stem. The push rod, lifter and rocker are not going to change as they are not subjected to any heat... so at most you can assume, worst case, is that you have a .005 MAXIMAL difference (aka variance) in stem length.

So if you set the cold gap at .006 (book number) it may close down to .001 due to expansion of the stem... and that's WORST CASE.

Set your valves cold, to the book number and you will not harm anything. It should get you a good idle. But the time you set the idle on the carb, adjust the dist for proper advance and make sure nothing is leaking you should be up to temp and then readjust the gap.

There is not a lot of mystery to this... nothing is going to break unless you did something horribly wrong. If you are unconvinced, set the cold gap to .008 or .010 cold.. you just need to be close enough to idle. Once you are at a good idle then break in the cam/seat the rings, put gas in it a drive.