BB Chev valve stem seal question....

[BillK]

Grant,
The Pioneer OS450's that Billy mentioned are the ones I was thinking of. The brand really does not matter, any Small Block umbrella from the late 70's should be the same. Your machine shop should have them, I keep a box of 100 on the shelf

Another option is to just put a small block "O" ring on the stem below the retainer. I had a customer years ago that used them on his BB engines and claimed they worked pretty decent. I guess anything to keep the oil from running down the stem would help.

[Tom Turner]

If you use GM urethane on the top of the retainer to seal the locks you dont need a seal. The dissassembly of the spring / retainer combo is a little bit of a PIA but it works great.

[MAURICE BLENDHEIM]

Grant... I have used the small block o-rings on several different applications and found they work. Had situations with smokey start ups and they were enough to eliminate the problem.

[BillK]

Grant,
The Pioneer OS450's I have measure about .720" so they should be ok. Another possibility I thought about this morning is the plastic umbrellas that were used on some of the mid to late 80's 350's that had 3/8" exhaust valve stems. Not sure of the size on those. They are a hard plastic and would not move around as much. Fel Pro number is SS72525 for 8.

[Grant Eldridge]

Thanks for all the help, Guys! I'll likely either go with the OS 450's, or the small block o rings. The ports are dry light grey, no sign of oil but just trying to be cautious while I've got the opportunity and the race springs are off. I'm using light ones to break in a new cam. Good time to add a bit better seal for now, then will machine the bosses next time the heads are off the engine.