I'm in the middle of replacing valves and springs on my 1980 f150 the kit that I bought came with umbrella-style valve stem seals. -there's not even anything left of the original seals for me to know what was on it. Is it advisable to go with this style of seal or would I be better off ordering a positive-type with the small spring on the end? (I'm not wanting to have the heads machined to make them work. Recommendations? Thoughts? Experience?

 

Like you said, the positive type seals work better but require the guides to the modified. The umbrellas work ok. Some oil going down the guide is not objectionable, it does help lube them some.

You are taking it to the shop anyway correct? You can't just replace the valves, the seats have to be ground and the valves have to be matched to the seats. The guides need to be checked also, sloppy guides will make it burn oil even if you do put seals in it, and valves don't seal well either with sloppy guides.

 

These are available on Rockauto's website. Its advertised as an umbrella but has the characteristics of the positive style. -no machining needed?



ENGINE TECH S2882

 

Yes, the ones that clip on have a spring down low on the seal and the spring snaps over the machine guide on the head. The picture above has the spring up high so it squeezes the valve stem itself.

 

"Back in the day", we would use Pinto valve seals.

 

I know I'm getting into semantics here, is the type with the spring any better than standard umbrella style? Seems like it would certainly seal better. Its about $18 for a set of these and if its the better way to go I'm gonna get them. I like to wrench on my truck, but I don't like redoing work that wasn't done right the first time.

 

I don't see that much advantage. You have a sleeve that comes with them (or use electrical tape) that covers the grooves on top of the valve where the keeper goes. You have to cover this area or the groove will cut the id of the umbrella seal. Then you have to force/slid them on. That spring may be a little tighter fit that's all.

All the umbrella seal does is deflect the oil away from the guide area, much like a rain umbrella. And it will sort of ride up and down with the valve as the valve opens and closes.

The positive snap on seals snap onto the top of the guide, and they don't move. And they are more of a positive seal, they do more than just deflect the oil away. But they are more expensive and machine work is required like you already know.

 

Thanks Franklin, I thing that's all I need to know.