Valve stem seals

[Mrbill426]

I have a question about valve stem seals.  I have two sets and both sets have the same type seals for the intake valves but the exhaust seals are different.  One is a "deep" umbrella resembling more of a thin-wall vacuum cap with a hole in it, and the other a thicker shallow "cup" shape.  Which is better for oil control?  If the deep one is, is it supposed to fit all the way down on the valve guide or ride up and down with the valve stem?  Same question for the intake seal, all the way down or riding the valve?

Thanks!

[1 Wild R/T]

Push them all the way down, the movement of the valve will find their happy spot...  The deeper cup keeps more oil out of the guide...  But then you gotta consider lubricating the guides... Exhaust doesn't suck oil in like an intake will, so do you really need the better seal? 

FWIW I use the deeper design seal..

[Mrbill426]

@1 Wild R/T  thanks.  I have never seen those shallow ones before and wondered if they were a new and improved type.  I have used the spring loaded Teflon ones in the past but did not opt for the added expense on this pretty much stock rebuild.

Push them all the way down, the movement of the valve will find their happy spot...  The deeper cup keeps more oil out of the guide...  But then you gotta consider lubricating the guides... Exhaust doesn't suck oil in like an intake will, so do you really need the better seal? 

FWIW I use the deeper design seal..