Which type valve seals ?

[IMJ]

I have original style umbrella seals made from Viton which are supposed to last longer than original rubber. I also have a type that holds the seal tightly around the guide and the valve stem by means of a small spring clip on both ends of the seal. I'm sure the spring clip style would seal better but would it be better to use the original style so the valve guides would get some lubrication.
I have new guides and valves and was thinking of using some STP on the valve stems prior to assembly. Would there be a better lubricating product to use for this area?

regards,

Jay

[Mike Van Veghten]

I'd recommend the stock type umbrella seal for the reasons you mention...unless it's a race car, then go with the other seals on the intakes only.

There are many "assembly" lubes on the market. If you are just assembling the heads, this might not be cost effective. But if you have a full engine to assemble..I'd go with a real assembly lube.
For the heads only...like STP, I'd go with the Lucas oil additive instead. Simillar in looks to the STP, but I'd be willing to be a little more receintly formulated. They do claim (per a phone call) they sell it to other companies for redistribution as an assembly lube because of it's high pressure additives.
I use it with Castrol GTX 20-50 in my 259 Lark. Been on the street almost daily for about 9 years with no known oil related problems.

Mike