Dauntless intake valve stem seals

I have a couple of fresh fully re-built Dauntless engines.
Head work is complete and all the guides were knurled.
Contemplating installing some stem seals onto the intake guides.
I just don't see any reason to put them on the exhaust guides.
Obviously these were not a factory item.
Any experience or opinions are welcomed.

 

Most times I will put them on the exhaust side before the Intake's...........although both can be beneifical. The Intake side does have vacuum to deal with when filling the cylinder......but the exhaust side also has vacuum do to the rush of gases passing by when the valve opens that create a low pressure area near the lower end of the valve guide........and of course the heat in the valve is also a factor in keeping oil out.

Personally I have never cared for the umbrella type deflector seal that rides on the valve.........I like the Viton material type Positive seals that are attached to the valve guide....these will normally require your heads get a quick machining of the valve guide boss area where they attach, easily done if you have the tool......much more positive and longer lasting.

 

Of course it's impossible to fully observe what occurs at the working valve stems and guides.

My theory is that exhaust gas pressure should push downward migrating oil back up the exhaust guide.
The hot exhaust fumes would tend to immediately burn the oil if it entered the chamber.

In my theory the intake stroke will suck the oil from the intake guides downward into the chamber.
The intake oil would get burned with the fuel mix and leave the tail pipe as blue exhaust.

I rather doubt that stem seals are of much benefit so long as the guides and the stems are in good condition.

Anyway I was considering installing some of the old "clip on" Perfect Circle seals with the Teflon stem band.

 

Not trying to change your mind on theory..........but what I mentioned above about the exhaust chamber creating a low pressure area and thus sucking oil into the chamber is a known.......Modern valve seals have come a long way from the old standby Teflon PC seals........a modern seal does a great job of allowing some oil to bypass the stem for lubrication / wear , while also controlling excess that would either get in the intake or exhaust track..........that could lead to a motor burning oil.........we hardly use any seals anymore on our racing motors do to the fact we create a negative crankcase pressure in the range of about 12-16 in.....
Do some research it's an interesting subject. http://www.federalmogulmp.com/en-US/Technical/Documents/Valve Stem Seal Facts.pdf

 

Tarry, thanks for the feedback.
But hey hey hey ....
The only single problem with my theories is that they are totally dependent upon insufficient data. R)