Umbrella Seal Question BBC

[rocks66ss]

I have never replaced these before and was wondering, Do these after you put them on stay stationary on the casting and the valve stem goes up and down thru it, or does it ride up and down on the valve stem. Basically how far down on the valve stem do you place them?


Rocky

[Hank70SS]

They should stay down on the head, seat them all the way down. If they ride up and down on the valve stem then they're not really doing any good. Should have some type of metal spring, clamp around them to hold them to the block. I hear the blue Viton seals are good. That was from a machinist that works mostly on Chevy big blocks. Some seals work too good and don't allow any oil past them. Need some oil to lubricate the guides and stems just not too much. I'm sure there are other good seals.

[rocks66ss]

Thanks, I wanted to be sure, I was told last night the one's with the metal ring are for small blocks, but was confirmed they seat all the way down on the valve guide.


Rocky