IMO Teflon would be better in this application, Viton seems to be a good choice for a NON friction seal as in Push rod tubes and oil cooler seals, they seem to have a unfavorable failure rate as a bell housing crank seal or HB crank seal, I will not use a Viton seal on a bell housing ever as they seem to fail,BUT,as a valve stem seal at least you can replace them with the engine in the car if one goes bad. Ideally you should have a Tight clearance and not run any seal at all as the small amount of oil sucked into the guide lubricates the valve stem and gives it longer life, a small puff of smoke now and then is a small sacrifice for a longer living valve stem. IMO only.
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Quote:
FliegerOriginally Posted by
Go Viton.I would rather pay a little more in the increased oil consumption and put up with some smoke than over heat a valve due to lack of oil. The head could fall off and rattle around in the combustion chamber, messing the whole cylinder up.If it leaks a little oil, what's the big deal? You will eventually flush the oil by adding a little at a time and you will be aware that your top-end is getting lubrication.
A little oil is fine. Any more and the heat (on the exhaust side) oxidizes the oil until you have a fur ball-size chunk of carbon in the exhaust port and on the valve head. More than this and the oil starts to migrate into the combustion chamber. However, you'll also notice the smoke from the tail pipe at this point.Either one of the above scenarios isn't preferable. We seldom have a choice and instead should deal with the existing condition. Lube to the top end is good, but oil leakage into the chambers via the valve guides is hardly a consistent method of distribution.Sherwood