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Viton Valve seal replacement on L32 heads issue

RegalGS98s

RegalGS98s

New member
I got some viton seals for my L32 heads. When you go to install the new seals, do you tap them on just enough for them to stay or should they go all the way down? I started tapping them on with a 12mm deep socket and you can see the seal opening with a little bit of space all the way around the stem like it's starting to stretch. The seals are going straight down and not on an angle. The machinist installed the first set of vitons and half of them were on crooked where I could see a little bit of space between the seal and the valve stem on one side. I haven't put these seals on as far as the machinist yet. Pictures of other heads on other types of engines I see with seals all the way on so how far on should they be installed? The heads were machined to allow a higher lift cam.
 


If you see space between the valve stem and the seal when the seal is installed, that is not going to seal, because the seal must ride against the valve stem in order to control the flow of oil. Since your heads have been machined to gain valve spring retainer clearance for a higher lift camshaft, you need install the seals far as possible to maintain retainer clearance, but not too far as to over stretch the seal as it goes down over the valve stem guide on the cyl head. I suggest that you try to install a seal, valve, spring, retainer, keepers, and then measure your clearance between the valve retainer and the seal when your valve is a maximum lift, you should have a min clearance of about .060.
 
They should be seated down fully, sealed around the valve entirely with no gaps, and should not be crooked or squished.

Easiest way I found was to lube them lightly with oil, install the valve, then use a 10mm socket and a deadblow hammer to tap them down. You'll know when it's fully seated because the hammer strike will sound different, and feel different.
 
Cool, good info. The best way I can describe it is seems the seals seat is too small diameter to fit around the valve guide post so then it wants to start stretching where the seal is made with the valve stem. When the guide is cut for more clearance, is it larger in diameter closer to the head like a taper? I got the viton valve seals from Intense.
With the seals just barely on now where they're right before stretching the seal to the valve stem, they have about 0.3" from the bottom of them to the bottom of the valve guide post. Currently there is 0.581" clearance with the valve spring retainer installed which is a bit close to my XPZ cam 0.570" lift. Wondering if I'm going to have to grind the edges down on the tops of the valve guides a little, haven't heard of anyone doing that so wouldn't think I should have to.
 
Just as an update I finally got the seals on. Seemed my machinist cut the valve guide posts uneven so every time I would tap the valve seals they would go on uneven and hence make the seal open more on the valve. I had to tap the seals on with the 12 point 12 mm deep socket a little and then twist them on with pliers a couple times till I worked them down.
 
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