i'm replacing valve seals on a 305 tpi. the positive locking seals that I bought from Napa did not come with o-rings...and when i pulled my first spring, there did not appear to be an o-ring there, so I figured my car didn't have them. well, i think the o-ring was there 20 years ago but has since fried off because I found remnants of what must be o-rings on other valves.

my question is: since i realized this late in the game, how critical is it that these stems have o-rings on them? based on searching this site, it seems the o-ring worked in tandem with the umbrella style seal to limit oil seepage into the combustion chamber...but if you have all positive locking seals (intake and exhaust), you may not need o-rings.

if anyone has any experience with this, please advise. thanks.

 

If you've got positive seals, you don't need O-rings.

 

Thanks, Apeiron. That's what I was hoping for.