Valve stem seals

[Freejax]

Hey guys just got my heads back from the machine shop, they said the guides were good and just reseated the valves. They look great, Best motors in Edmonton AB. did a great job and are a good group of guys to deal with. My question is about the valve stem seals, I have been reading and some people have said to put them on the intake valves but not the exhaust valves and some say use Viton or teflon, What do you guys think? When I pulled my engine apart there were little to no seals on any of the valve stems, they must have disintegrated over time or were not installed in the factory, the one that I did find was on top of the valve stem above the spring, correct me if I am wrong but don't they go in the spring under the cap? If you have any pictures or diagrams that would be beneficial.
Thanks Guys I will be posting the pictures of my fresh machined heads soon.

[azdave]

Yes. Under the cap inside the spring. Many people say their use is not that critical due to the horizontal layout compared to a normal V8 where they are upright. I would use either style you have on hand (intakes only) and not worry too much further about it.

[Scott V]

seals arent really used on the exhaust.
seals on the intake....................some people install them - some dont. factory engines had a little seal.

-Scott V.

[viewmaster]

I know i am dredging up an old thread, but i have a question re: Valve Stem Seals. Has anyone installed these seals while engine is in the car? I saw a show on velocity that had a guy do this with a homemade lever tool and shop air introduced into spark plug hole, to hold valves up. Anyone do this on a Corvair?? If not, im gonna try and make a tool and take pix doing it.

My 110 PG burns oil, and i want to eliminate the intakes as a source, since im sure i need a valve job.

-m

[toytron]

Yes, I have done it before on v8s. You have to take out the spark plug and insert the adapter that you attach the air hose to. It doesn't need a ton of pressure just needs enough to keep the valve seated. It should not matter about being at tdc because you would be backing off the rockers and the valves would be closed at that time. Then you would use the special valve spring remover like this one
http://m.lowes.com/pd/KD-Tools-Automoti ... ef68039ae7

You compress the spring while the air pressure holds it up. I actually would bump the valve spring retainer with a rubber mallot before just to free up the retainers. Anyhow after you compress the spring you would remove the keepers and take the retainer, and springs off. Clean and lightly lube the valve stem and insert the seal. Then put the spring, retainer and keepers back on and release the spring tension on the tool. Make sure the keepers are seated then move on to the next one. Only do one at a time.

Sent from my SM-N910V using Corvair Forum mobile app

[toytron]

Oh sorry btw this is the pressurizing tool http://www.jegs.com/i/Crane+Cams/271/99 ... hgodCvAOIQ


Sent from my SM-N910V using Corvair Forum mobile app

[erco]

seals arent really used on the exhaust.
seals on the intake....................some people install them - some dont. factory engines had a little seal.

-Scott V.

Old post, I know, but this subject is near & dear to me.

Seals have never been used on Corvair exhaust valve stems AFAIK. Seals would burn up quickly on hot exhaust valves in these hot-running, air cooled engines. Besides, exhaust pressure pushes oil outward, so exhaust valve guides are not the source of burning oil. Oil leaks (smoking/oil burning) can only come through intake valve guides. Intake valves run much cooler than exhaust valves, as the incoming fuel/air mix absorbs a lot of heat. Cylinder vacuum pulls oil in through the valve guides.

Never heard anyone say that intake seals were optional. Is it legit to even suggest leaving them out?