Valve Keepers 280SL

[MikeSimon]

I am working on the cylinder head off the motor and want to take the valves out. I am stuck at the first cylinder, because one of the keepers does not come out. I do not want to use any sharp tool to pry or knock. Any words of wisdom?

[Cees Klumper]

Do you have a proper valve spring compressing tool? I've dis-assembled a couple of these heads and have not run into this issue before. Try a couple of the other valves to see whether they are more compliant.

[MikeSimon]

Yes, Cees, I do have a "proper" tool. As I said, one keeper comes out easily, the other one sticks.

[Shvegel]

Have not run into that on the few heads I have pulled apart. Could you knock it sideways with a plastic or brass drift. An old mechanic I knew used to always rap on the top of the upper spring perch with a brass hammer before taking the keepers out to shake things loose.

[MikeSimon]

I will get to it again. No idea what is going on there.

[ja17]

The exhaust spring assemblies will not compress much because of the wide sodium filled valve stems. A small magnet, a little pick, and a little rocking of the compressor should get the job done.

[MikeSimon]

It is the inlet valve on cylinder 1 that gives me the problem. The spring compression is not the cause. I can get the spring down to almost see the complete keeper. One just falls away from the valve shaft, the other one is like welded to it. If the problem persists, I am planning to make a small two-prong tool to tap against it and hopefully get it loose.

[Benz Dr.]

What ever the cause is, I would be finding new keepers because it sounds like the ones in there now are damaged.

[MikeSimon]

Taking a little more time and waiting for the "mind over matter" moment, they finally came all out. All valves have been removed.
There are different stem seals for intake vs exhaust. The exhaust seals come off easily. What's the secret on the nylon intake valve stem seals?
Is there a special tool required to remove them or do they come off by force and damage?

[Benz Dr.]

 Since they rely on what I'd call a friction fit intake seals need to be fairly tight. I wouldn't plan on using them again so pry them off with a suitable tool.

[MikeSimon]

Thank you Dr.! I have new ones. Just want to make sure I don't do more damage while trying to fix something. Usually what happens...

[Shvegel]

With valve stems the size of tree trunks I think you are pretty safe.  I worked on an Around the World rally car that over-revved the engine and blew the cam towers apart.  They found parts and had them flown in, we put it back together and did a leakdown test.  No bent valves.   Regardless a couple seconds on a valve grinder will tell the story.

[Benz Dr.]

If you find more than just small bit of radial play of more than .002'' the valve guide or valve stem may be worn. At some point valve stem seals are only going to work for a while and may if fact be a waste of time.

[MikeSimon]

What is an easy way to measure "radial play" of the valve stem. I visually inspected them and they all look rather decent. Considering that the guides are some kind of brass and the valve stems are steel, you probably do not see much wear on the valves.
All guides sit perfectly fine and I would hate to replace the valve guides. I did it on a motorcycle engine once and it was a pita. These had to be reamed after installation.
0.002" translates to 0.05 mm, which is not much and you need to have pretty good equipment and a serious set-up to measure this.

[Benz Dr.]

Optimum play is about .0001 - 0002''  at .0005'' you can really start to feel the valve stem wobble in the guide. You can also measure the valve stem where it slides up and down then compare that area to where there is no wear so see if there's any difference in size. G

[MikeSimon]

I would think the wear in the valve/guide is mainly in the guide, as it is some kind of brass. The valve stems are hardened steel and probably wear much less than the guide, or?

[Mike Hughes]

When my engine burned an exhaust valve, it had previously been burning a lot of oil for some time.  It turned out to be worn valve guides.  Chuck Taylor and Ray Schlicht sent the head out for reconditioning, new valve seats and guides.  Other than the burned valve, and maybe one or two others, most of the valves exhibited next to no wear and were simply reconditioned and reinstalled.  The engine has run great with minimal oil consumption ever since.

[MikeSimon]

Since they rely on what I'd call a friction fit intake seals need to be fairly tight. I wouldn't plan on using them again so pry them off with a suitable tool.

A tool that I have used on motorcycle valve seals worked quite well. They came off easy, without even being mangled.

[Benz Dr.]

Interesting tool. Are you going to change the ball studs?

[MikeSimon]

Should I?
Before the car developed the running issue, it performed quite well. No noises, no oil consumption.
I am doing already more than I originally wanted. Some friends suggested to just squirt oil into the plug holes and crank it after it was parked for 20+ years.
I did not want to do this and took the head off. I am cleaning the carbon deposits off, putting new seals on the valves and lapping the valves.
I really do not want to go into it much deeper and do not want to change the valve guides, etc. before I find out and remedy the actual issue I have.
I know, having the head off makes it logical to address everything possible. Then again, I could take the whole engine out and have it rebuild.
What is the potential problem with the ball studs?

[Tyler S]

Those ball studs look very crowned. (Round cylindrical metal) protruding from the top of the balls. This makes adjusting the valves a real pain and they never seem to hold an adjustment. You can replace them or grind off the crown if the rest of the ball is in good shape. I opted for replacement when I did my head work. Made adjustment a non cursing job. There is a vendor somewhere that sells just the upper ball stud portion instead of the entire stud/base assembly. I’ll see if I can dig up a recipt.

[MikeSimon]

  Oh man, this is turning into a rather bad dream! Looks like I do need to replace these. But then, what about the rocker arms? Shouldn't they be replaced also? You would think a badly worn ball goes with a badly worn socket.

[Benz Dr.]

Here's my take. Rockers will wear as much as the ball stud so you might want to consider that. I would take your head to a machine shop and have them inspect all of your parts. Have them clean the head and check it for straightness, check your valves and guides, then give you a report. Odds are they're going to say that it needs work because that's what they do. Your problem is in deciding to do needed work now or sticking all back together in the hopes that it will run OK. Things don't un-wear and 230/250 head gaskets are NLA right now. 

[MikeSimon]

Some of the stuff I can assess myself. Head is straight and valve and seats look OK. Play in the guides is difficult for me to measure. Worn ball studs and rockers will most likely have to be replaced.
One of my major concerns would be to find a shop that knows ANYTHING about these particular heads.

[Benz Dr.]

Any good machine shop should be able to work on it. Having experience with our cars sure helps.