Okay, "Oldsmobile Elementary" is now in session...

Just this week I have been introduced to the innards of an Olds head for the first time. I have worked on Ford 4 poppers but the Olds' have some differences I need explained.

First are valve guide seals. On my Ford, the seals are secured to the guide cast in the head. MAkes sense.
All of the ones on my Olds heads are stuck to the valve stem and actually ride on them. Then the valves are up, so are the seals. I would think they are supposed to stay on the casting, but maybe not??
I was thinking on replceing them but now I am not sure if I should...

Next, what are damper springs? I see them on EXH valves only. what are they for?

 

The umbrella seals will ride up and down the valve stem. Very simplistic. They live up to their name don't they?

Now is the perfect time to do them Rob. Not just a "might as well". You really should do it. I would hate to have to get back into the motor in a couple of years and get your newness all dirty again. I would replace the keepers as well.

The damper spring..dampens harmonics. Its kinda like a shock absorber, controlling all the bouncing around and dancing the springs can do. I've seen them on all the valves before. Can't say why they chose to use them on the exhaust only. I really don't think they help absorb and dissipate the heat in that area...but maybe they do.

 

So they are supposed to do that - interesting... Explains the "umbrella" term and also the fact that my new ones are a hard nylon material.

So what are the failure modes of these? On the Ford the hole around the valve would enlarge from friction and as the seal hardened (after 12 years or so). Oil will then migrate down the valve guide, thus the engine would burn oil.

These umbrella types would seem fine as long as they are intact and stuck to the valve. It seems that there would be no wear points on them. Just hate to change all these if they are not broke and risk braking something else.

And why change the keepers? On the Ford, they were always reusable (as long as none were lost)....

Now i have noticed that the tops of the valve stems have a burr on the top. How is this removed?

Thanks for the good reply!

 

Any thoughts?

 

C'mon, engine experts...

 

Did you try a fine file?

 

I haven't touched them, other than to do a light cleaning.
I am trying to figure out if I really NEED to change these seals... The do not seem to have a wear point like my Ford ones did.

My philosophy in life is don't try to fix what isn't broken, unless you want it broken. Been there, did that.

 

Well, it is pretty much the same like you said of the Ford. The umbrella seals get hard and crack, and break and fall off. Like you said then you start to burn oil. Pretty much the same on all.
I have found some Ford valve stem seals that fit tight over the valve guide and fit the Olds stem. The other problem you have is valve guide wear. Because of the rocker design the rocker pulls on the valve when it opens and over time wears the guide. If you have the head off and the springs off you can, you can open the valve a small distance and if you can rock the valve back and forth in the guide a measurable amount you need to replace.
But all and all, it is not hard to replace the seals. If you have them apart, you need to do it. If the heads are still on and you do not use a measurable amount in oil consumption, like you said "if it is not broke, don't fix it" .

Gene

 

Rob, I used to do hi-perf heads for a living, and suggest you take them for a valve job!
The 'tip' of the valve is supposed to be ground flat, without burrs, so as not to wear out the rocker arm tip.
There's a fixture on the valve grinding machine to do this properly, and there's NO other way!
Also equalizes the valve length from grinding the valves and seats on non-adjustable rocker arms.
Umbrella seals let a little oil lubricate the guide, as they'll live longer on a stock motor.
I used to shim the springs to 110 - 125 lbs., as I felt stock was a little low!
Good time to blend the bowls and match port for more MPG + power, too!!!

 

X2 on what "Rickman" said.

Gene

 

Change them or you will find them broke in hundred pieces laying in the bottom of the head and god knows where else the next time you look under the valve covers. That's the mess I found under my covers when I replaced the gaskets.

 

The seals cost around $15.00 and it takes approx 2 - 3 hrs to change them.