The Stovebolt Site Forums The Shop Area Engine Shop Valve stem seals on 63 292

Trying to clear up some questions on what seals were used for these heads.

I read that the Positive Intake seal is not used prior to 1981. Just looking for confirmation.

The stock seal will be the standard O ring type. However someone may have installed something else if there was a problem or as a possible cheap substitute for replacing worn guides.
Fred

I figured all the valves use the washer type, however, does the washer go past the second groove, or does it sit in the groove?

The top groove is obviously for the keeper, just not sure if the seal goes all the way down or not?

Here’s a pic of one of the valves on disassembly.

EDIT: I think I just answered my own question, the two grooves are for the keepers. The seal would obviously slide down as far as it could go. Hope I’m right here.
😬

I think the o ring type goes in the groove below the keeper.

The lower groove is for the O ring seal, which is installed on the valve stem after the spring is compressed, then the keeper fits into the top groove. Release the spring tension VERY slowly to avoid dislodging the O ring as the spring retainer slides over it. I oil the rings a little as I install them.

Just a word of caution- - - -if you choose to use a positive stem seal or an umbrella seal instead of the O ring, DO NOT install the O ring as well. The valve guide needs a very slight amount of lubrication, and totally stopping oil flow down the guide will result in rapid valve stem and guide wear. I've seen guides with over 1/16" of clearance around the valve stems after running a while with both types of seals installed. Those engines used oil by the gallon!
Jerry

It seems the o-ring washer would have a hard time fitting in the spring retainer. The OD of the washer is too big to fit into the spring retainer.
Also, when installing these, how can you be sure the washer is sitting correctly in the groove AND retainer? There's no way of seeng this.

The image in your post shows a totally different type of valve stem seal.

And, what good would the seal do if it is in the groove? It is way above the valve guide, where oil would seep into the combustion chamber.

more pics - these are with the valve in the head and the keeper on the retainer. I don't see how the seal does any good if it is in the 2nd groove. It is nowhere near the valve guide where the oil would seep through.

I think the purpose is to slow down the oil that collects in the valve spring retainer from flowing down the valve stem.

SimS

I think you are missing the point of how this works. The seal does not go below the retainer, you install the spring and the retainer on the valve stem, compress the spring and retainer, install the O ring on the groove toward the head and the keepers on the upper grove on the stem, and release the spring. Everything is now in it's proper place. The hat type seals fit over the stem and the guide, these don't work like that.
Fred