The Stovebolt Site Forums The Shop Area Engine Shop Installing valve stem oil seals

My 1956 head is now back together and the stem locks just don't seem to be firmly locked into the spring cap. So I have to question my install. I compressed the spring ...slid the oil seal in place and placed the locks in place....released the spring compressor. All done but just concerned about the locks seating in the cap...can't afford to drop a valve at start up.

Some locks are a bit narrow. They look loose. If the lock fits the valve stem, nice tight and flush all around, then they should be fine.

If the gap in the split locks is completely closed up the locks and/or the groove in the valve stem is worn out. I install all new split locks on every valve job- - - -it's cheap insurance. There should be a slight gap between the locks when they're in place and the retainer is pushed up snug against the taper.

It's easy to pinch a piece of the O ring between the keeper and the retainer, so if there's any doubt, re-compress the spring and check the O ring.
Jerry

Never saw that Jerry, how do the keepers wear out since they
don't move once they lock into the taper in the cap?

dg

The hammering action of the rocker arm on the valve stem tends to beat the keepers up, particularly on a solid-lifter engine with slightly wide valve clearances. A radical cam with lots of valve spring pressure and/or high RPM makes it worse. It's something we were particularly careful to check when doing a rehab on the race engines during a mid-season freshen-up.
Jerry

I keep a spark plug boot attached to a Mighty- Vac for checking to be sure the O-ring seal is good and in place.

Denny you would be surprised how much valve train moves when watched with a strobe light. Make a guy wonder how they even stay together!

Like to see that video.
dg

I pop each valve on the stem with a hammer to let the spring seat each set of keepers. It's quick and easy to rap each valve a few times, just to be sure everything is seated properly. You can also hear if a valve is bent or not by the way they hit the seat.

...just make sure you don't have your head stuck over it in case keepers aren't seated. Yeah, I learned from experience years ago.

I launched a triple spring setup from a roller cam engine all over the shop one night when the valve spring tool slipped off just as I was getting ready to put the split keepers on. We used the retainers and keepers with the 10 degree angles on those engines. Standard split locks and spring retainers have a 7 degree angle.
Jerry

If it's going to come loose, better to be in the shop then on the engine......

When you mess with heads long enough, your bound to launch a spring or two.

Joe