XJOZ

I have a 91 with the 4.0l engine.

Bought some 'valve seals' and was just starting to do the first valve when i realised the parts Jeep sold me where valve seal caps and not the rubber seals.

However there are no caps on the seals in the first place. Are the caps optional or not used on some heads or huh???

Are the caps thought as sufficient to seal it again or are the rubber seals also needed?

Thoughts?

Thanks in advance.

cruiser54

I think you have the valve seals....

XJOZ

Ill try and clarify:

This is what i have in their now(assume stock):

http://www.4wd.com/Jeep-Engine-Perfo...pn=OAI17443.03

This is what dealer sold me:

http://www.4wd.com/Jeep-Engine-Perfo...pn=CRO53009886

The later being refereed to at other sites as a 'cap' or 'crown' not sure if they replace the seal or go over top as the name suggests. The OD of the seal is just a hair larger than the Id of the 'cap'/'crown'.

I went to dealer and the tech said he thought it was a replacement but wasn't sure and had no hands on with it.

i just don't see any application info for the 'cap'. I may be over thinking but also don't wanna get stuck as the nearest old school seals are a week away if needed.

jedijeb

The 302 Ford I rebuild years ago used valve seals like the ones you have. They are like an umbrella cap, the do not physically seal to the head but move up and down with the valves, but still cover the top of the valve guide. They keep oil from running down the upper part of the valve stem and into the guide. They will keep oil from running down through the guides and into the cylinders unless something plugs the return and the oil pools on top of the head to a level above the top of the guides. But if it is pooling that deep, you probably have other problems to worry about.

cruiser54

They are both valve stem seals. Just different design.

Doing intake only?

almido

Technically they are both "seals" as the other post said. One is the "perfect circle" type which seals to the guide boss with a built-in steel clamp and has a Teflon inner seal that wipes the valve stem as it moves up and down. The other is called an umbrella seal or as some hot rodders say a "cheap-o" seal.

Actually, a lot of GM stuff came with the perfect circle type while Chrysler used the umbrella type. Not cheap-O and they come in silicone for a little more $$.

"Back in the day" I had a head shop and we used the Chrysler seals because they would "weep" just enough oil at high RPM the prevent the valves from galling the guides for lack of lubrication. Not enough to "use oil" but enough to prevent damage.


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2001 sport 240k miles and unmolested........so far !

XJOZ

Ok thanks for the input. Once again my Cherokee will live to see another day due to this site and those who make it happen.....