I am replacing the valve stem seals. On the exhaust, I am having trouble getting the retainer over the o-ring when pressing down to get the keepers on. It's a snug fit. It keeps popping the o-ring out of its groove and down the valve shaft.

Do I even need these anymore with the new lower skirted seals? If I do, I can't see how it would hurt if they aren't in their groove.

 

An o-ring is just fine on exhaust valves.

With intake valves, there is suction around the guides as the piston is pulling air into the cylinders when the intake valve is open. This can also pull oil past the guides and into the cylinders.

On the exhaust valves, when the valves are open, the piston is pushing exhaust gases out of the cylinder so any minimal oil that gets past the guides just goes out the exhaust manifolds. Valve guide oil control isn't as critical on the exhaust valves and since the exhaust valves get much hotter than the intakes, a little bit of oil for cooling doesn't hurt.

My race engine isn't considered a very high mileage engine. I don't have any valve seals on the intakes or exhaust valves.

 

You don't use both positive seals and o-rings at the same time.

And you are installing the o-ring incorrectly. You compress the retainer, then put the o-ring on, then the locks. O-rings are ancient history. The newer valves don't even have the groove for an o-ring. When running stiff springs, this groove can be a failure point.
You also need to watch your retainer-to-seal clearance. By using both, you are really reducing your clearance. This is one of those things where you think you are doing something good, but in reality, you are causing more problems.
When those o-rings get hard and brittle, they will fall off and make their way into your oil pump pickup, causing yet another problem.

 

Thanks so I figured out the retainers go on first and I am getting the o-rings in. I've done two sets of valves already. Think I should go back and remove them?

 

All the O-rings do, is prevent oil from running down the valve stem from the keeper area to the guide. They are only marginally effective at doing that, and are totally worthless if you have positive seals already there, because any oil that runs down the stems, still can't make it to the guides.

Leave em out. Also leave those splash shields out. Not only are they ineffective just like the O-rings, but also, they add dead weight to the valve train, at one of the worst possible places.



No need to take the O-rings back out, if they're already in. Once they're in there right, they'll at least stay put, until they crumble to dust. If you have any on the stem below the retainer though, go ahead and remove those.

The rope method is pretty eeeeeeeezy, don't you think?

 

If you do leave the splash shield out, you have to make up for its thickness with a shim - under the valve spring. Most shims are marked "this side up".

 

According to fel-pro, I am supposed to use both the lower and upper (o-ring) seals. Both come in their kits.

 

I used positive, silicone, umbrella style seals that ride with the valve - not attached to the guide boss. No o-rings, no rotators, and no splash shields. I have zero oil consumption and zero oil puff on start up, etc. I would say the new stuff is pretty effective.

The Fel-Pro stuff is actually pretty dated. These are the ones I used - the red silicone ones with the spring loaded lip:

http://enginetech.com/products/produ...ve-stem-seals/

Super easy too.

 

ok so it’s my first time doing valve seals and I did my whole valve train today, but like this guy originally, I put the o ring under the retainer. Obviously I don’t want to go back through, take all the rockers off, compress the spring and so on. If I leave them, will it hurt is what I’m getting at. If so then I’ll go back through and take them off. Thanks in advance

 

I would remove them and install silicone umbrella seals and nothing else. The o-ring is not supposed to be below the retainer. And they are outdated technology and shouldn't be used anyway. Also you DO want some oil for the guides. They do need some lubrication. Not a lot, but there has to be a little.

GD

 

thanks for the response. I guess I’ll go through them tomorrow and remove the O-rings. Not gonna spend more money and wait for new seals honestly. I want to get it on the road by Wednesday at the latest

edit- I’m also doing this with the heads in the car and one hand due to a torn tendon. Fun times lol