not familiar enough with the small block to know but I am working on a 1970 318 and the exhaust valves are of equal height and are also higher than the intake valves around a 1/16th of an inch more or less. i did not measure it. Is this normal?
Posted By: MoparforLife
Re: 318 valve stem height - 05/28/11 09:13 PM
Installed valve spring height should be right in about 1.68 (1.67-1.70) Relatively level across all 8 valve stems per head. If they IMO the valves are not in the seats correctly. either too deep for some or not deep enough for others.
I would have that they should be equal also. I did measure the difference and the intakes are between .065-.075 lower than the exhaust. It's as if somebody set the stem height that way. The engine has been rebuilt at some point.
Posted By: MoparforLife
Re: 318 valve stem height - 05/28/11 10:42 PM
Why would they. The spring is what is set to installed height and they are all (intake & exhaust) set at the same installed height. What you are getting is a seating variance as I stated above.
Posted By: MoparforLife
Re: 318 valve stem height - 05/29/11 01:30 AM
Or somebody doesn't know not to bear down on the seat grinder. Personally I would have them done right. The exhausts will not last long cut into the head that way. As a rule Mopar heads seem more tolerant of UL gas and seem to have a harder seat than brand X but once that surface is cut down like you say it is not a good thing and they won't last long.
Posted By: mr_340
Re: 318 valve stem height - 05/29/11 05:42 PM
It seemed to me that all the heads came this way from the factory. If you are running a mild hydraulic cam, it will compensate for the difference.