Exhaust Valve Seals????


New Member
Jan 8, 2007
I am about to install seals on my bronze exhaust valve guides...slight smoke on start up... I am afraid to seize a valve going down the track.....210 210 roller cam opinions please
If the clearance is correct on the stem to guide, you'll be OK. I originally went with no seals on the exhaust and got too much oil in the port, oxygen sensor, etc. Installed some viton seals and it cleaned up. No more smoke and less contamination of the O2 sensor. And I'm running methanol fuel which does not lube the upper end at all. Check with your head man and make sure he put in enough clearance.
:D what would you suggest... clearence ,and any idea on type of seal

On the exhaust, minimum .0012" to .0015". Normal would be .0015" to .0017". Proper honing must be performed to eliminate any taper of the guide bore. I prefer Viton material guide seals. TA stocks them. I've used teflon and the current offerings have not work well for me. Some would work there way off the end of the guide and get munched by the retainer.
THANKS ...for the info ,,i was thinking .oo2 to .oo3 just to be safe anbody ever seize a valve at 5000 rpm:mad: I DID
I would consider .003" to be a max limit and I have heard head guys say that .003" is fine.
One more note for aluminum heads in a strictly high performance application. For the exhaust only, .0015" to .004", with .005" being the maximum allowable wear. How loose you run the guides will dictate how many good miles you will get from your valve job between rebuilds. I'm with you on the .003" target for playing it safe.
You're welcome. And don't forget to take your vitamins.

And from a "Chiropractic" point of view .........
Make sure your valve train geometry is correct since you are using bronze guides. :eek:

And perform your "muscle stretches" daily. :D