Exhaust Valve Seals - Merkel Recommends

[PaulRV6]

Hey folks, just read article in Merkels website about 3.8L build, he says to use seals on exh valves. I know factory did not put them on but is there any benefit to using them?
If so what ones to use and are they a matter of slipping over valve stem?
Opinions please.

paul

 

[The Radius Kid]

I'll catch flack for this one,but don't use them IMO.There was a reason GM didn't use them[improved stem oiling under stress].Just make sure the guide clearances are right.I would say that if you *have* to use a stem seal on the exhaust side,use the factory style rubber,no teflon.I'll put my flame suit on now.

 

[Ormand]

Valves/Seals

I thought that Merkel used different, after-market exhaust valves, which don't have the little "oil groove" that the stock valves have. The exhaust valves get much hotter than the intakes, so the stock material may not hold up, either. And since there's no vacuum in the exhaust system, like in the intake (well, sometimes my car is not under boost) the oil doesn't get sucked in as much. If you want seals, teflon would hold up to the temps, but I don't think it seals as well. Probably good enough for exhaust, though.

 

[PaulRV6]

You are correct, Ormand. Merkel did not use the stock valves. So the stock valves are made such that no seals are to be used? Sounds reasonable.

paul

 

[timothydog]

I read the article too.
Recently I replaced my springs and intake valve seals and I notice my car smokes at startup only when it is warm. Can't figure it out yet but it isn't turbo or pcv.

 

[FJM568]

To use valve seals on the exhaust side, requires the valve guide to be machined for them...It isn't a "might as well add them while I'm replacing valve springs" type of thing unless the heads are off the car...

And as someone has mentioned, there is a reason GM didn't have them on there...

 

[PaulRV6]

Thanks, my question is answered.

paul

 

[Outpost]

I drive the car in that article and it seems that the exhaust valve stem seals work well.

 

[turbojoe]

the september 2002 issue of GMHTP contains the "Buick Power 101 part 3" article which has a brief explination on this matter. it claims that this was merely a cost savings issue and a typical warrenty fix for the resulting smoke on start-up was to pull the valves and install straight-stemmed replacements. the article says merkel installs straight stemmed valves and machines the guide down to accept standard oil control seals.

now, this is just what the article says so its not my theory on the subject. i just thought that you guys might want to know which explinations are floating around there.

 

[PaulRV6]

exhaust seals wanted

Are there any valve seals that I can use with the stock exhaust valves without having to machine the guide down? I have the heads apart for a quick cleaning (after 40 miles) and I would rather not have to take them to get machined again.
With the talk about smoke on startup I would like to do something about it now as simply as possible. Thanks for the help!!

paul

 

[NJTurbo]

Does anyone Know if Jack has any luck building Stage 2's?

 

[Buicksx2]

Originally posted by njturbo
Does anyone Know if Jack has any luck building Stage 2's?

>>> I'd be interested to hear the answer to this question also.