Valve Stem Seal To Valve Spring Clearance

[Hrdlx62]

Is there a spec for valve stem seal OD to valve spring ID diametrical clearance? I have .020 clearance on a set of heads I'm working on now. Is that going to be sufficient? Or should I opt for the the reduced diameter seals? I'd rather not use the small seals as they can be a pain to install. Thanks.

[PackardV8]

Additional detail might help when asking down to the thou:
1. What locates the spring(s) ID/OD?
2. What RPM range?
3. Max RPM limiter or "rev to pass?"

[mag2555]

I would not have the warm and fuzzies about trying to get away with only .020” once things heat up and expand

I have never found it any harder to install .500” seals as compared to .530” seals if there the metal band Viton type.
I have not used the full metal encased type in probably 35 years.

[PRH]

At .020 there will very likely be some contact.

The question is........ will the contact be hard enough to cause any problems.

[Hrdlx62]

Im not talking guide OD here, seal OD. I'll bite the bullet and put the small OD seals on. .020 is pretty close.

[mag2555]

Yes, that’s how I am understanding you.

[hoodeng]

.060" to .080" is default minimum. Any contact can bounce the seal off.


Cheers.