Valve stem seals question ?

[bentpshrods]

  Back when I first got my car I rebuilt the motor. Bored it .030, new bearings, cam, valve job ect.  Only put about 3-4k on the motor when I lost the tranny. Then the car set for 21 years untill I fired it back up 3 summers ago and cruised all summer putting about 2,500 miles on it then. The problem was that when it set for the week and then when I would start it it would smoke really bad till it warmed up. Blows white smoke after sitting. I am thinking that the valve stem seals are  dried up and bad from it not running for 20 years.  I bought a complete gasket set (felpro) when I got it running and it had these 2 style seals in it.  I took the springs off of one cylinder and booth seals looked the same. What is the difference in the two styles. There is only eight tall seals and eight smaller seals. I was thinking one was intake and one exhaust but the one cylinder only had the tall seals.  I have some left over from the original build but that was 25 years ago.  Would they still be useable ?   

[Super Blue 72]

  Interesting.  It's been a while since I did a valve seal job but I thought that the intake and exhaust seals were the same? 

I would not use 25 year old seals if I had the choice of using newer ones. 


Weird, Summit has a similar set, but it doesn't specify what engine it goes to. 

http://www.summitracing.com/parts/DCC-4120492/


See this post on Moparts.  Not sure if it's useful or not.

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=5439126&Main=5439126

[Chryco Psycho]

I would use the positive type seal instead of the umbreller type , most of my builds use the smaller positive seal to clear the double valve springs

[72bluNblu]

The taller seal (on the left) is for the intake valves, the shorter one on the right is for the exhaust valves. If they're like the one's I have the taller ones have ribs on the inside to grab onto the valve guide.

Positive stop seals are better at sealing and smaller (needed for double springs as CP mentioned) but you also need to have the valve guides machined to fit all the ones I've ever seen. Not a problem if you're already planning on rebuilding the heads or having other work done, but if you just wanted to replace the seals you'd have to stay with the umbrella type.

[72cudamaan]

Use the umbrella seals on the exhaust. In a stock application to mild street use, your valve guides will last longer. The exhaust guide especially needs a slight bit of lubrication to keep from galling. The taller seals are for the intake. The intake seals are a positive type because on the intake stroke you could actually pull quite a bit of oil down the valve guide.

[moper]

The originals would have all been the same large umbrella seals on both. Later engines had the positive seals only on the intake, asn the seal has vacuum o the valve side. Exh has little or no suction and the oil going on the stems cools them and the guides. So they only use that short umbrella. I've used the positive type on intake and exh before, especially when the heads have marginal or bad guides to begin with.