I am replacing my valve stem seals, please help

[Sonic]

I'm going to replace my valve stem seals on my stock '73 240z. I'm sick of that grey cloud behind my car when coasting down hill. Besides the seals, what else should I get that might get lost or break when replacing them?

Also, where should I get the seals? I heard that Autozone sells them, or should i get them from MSA?

Thanks

[280zx Fever]

you will need the following

top overhaul kit which includes

headgasket

manifold gaskets

fuel pump gasket

rocker cover hasket

timing chain inspection panel gasket

valve stem seals.

What you do is take the head off dahh and the manifolds and then remove the rocker gear cam etc...

Remove the valves from the head or just take it into a engine recondition place they will re grind the valve seats and replace the guides if they are worn and test out the springs aswell

The valves WILL have to be lapped in.

It cost me $4 to grind each valve and $4 to seat the valve so your looking at around 100 to get the head done with a light skim, then up to 150 for the top overhaul kit.

Good luck

[gramercyjam]

If you just want to replace valve stem seals, you don't need to remove the head or the manifolds. Just the valve cover needs to be removed.

--John

[kmack]

John is right. The valve seals, springs, and seats can all be replace with the motor in the car and w/o removing the head. The cam has to be removed along with the cam towers. Make sure you use a screw driver or a piece of blocking to hold the cam chain up otherwise if it falls down into the block, then the whole engine will need to be taken out and apart.

This is taken from an email I got about 2 years ago:

"The local Nissan dealer says that the BROWN seals, while superior to BLACK seals (brown feels more flexible, and is made in a different mold, but design appears nearly identical), are not specified for the Z car. They are, however, specified for a TRUCK. The part number on the bag is 13207-81W00. Mr. Chu had specified #13207-21002."

I used the brown ones when doing my motor. But they came in a gasket set I bought from MSA.

[Ed]

I would think you could do it without removing the cam. Couldn't you remove the slack from the rocker arms. Then pull the rocker arms out of the way. Stick a piece of tubing in the spark plug hole (to hold the valve up) and turn the engine (by hand) until the piston pushes the tubing against the valve. Next use a spring compressor and remove the springs. MSA sells a spring compressor that requires the cam to remain on the head.

If you do decide to remove the cam then get the cam chain tensioner tool. It holds the cam chain tensioner in place when there is slack in the chain. If this tensioner pops out of place you will end up having to remove the front cover. P.I.T.A!!!

[LanceM]

Depending upon the tool you use to remove the keepers you may or may not have to remove the cam. In any case you are going to have to hold the valves closed somehow. The tubing as mentioned above may work but I don't like the idea of sticking something in a cylinder that I may not be able to get out. I once used the old trick of using clothes line in the cylinder to keep the engine from rotating while trying to break free some flywheel bolts, damn clothesline got cut and I had a hell of a time getting it out with out pulling the head! Won't ever do that again!!!

My suggestion is to take an airline coupler (quick disconnect male end) and an old spark plug. Knock the porcelin out of the plug and weld in the coupler. Place it in the sparkplug hole, remove the rockers so the valves are closed and then pressurize the cylinder with your compressor. As long as the air line is hooked up the valves will stay closed. Do your work then move the adapter to the next cylinder. That way nothing gets into the cylinder but compressed air!

[Bambikiller240]

Originally posted by LanceM

My suggestion is to take an airline coupler (quick disconnect male end) and an old spark plug. Knock the porcelin out of the plug and weld in the coupler. Place it in the sparkplug hole, remove the rockers so the valves are closed and then pressurize the cylinder with your compressor. As long as the air line is hooked up the valves will stay closed. Do your work then move the adapter to the next cylinder. That way nothing gets into the cylinder but compressed air!

Should be able to buy the spark plug/air line adapter without going through the bother of welding up your own. Check around some before you go through the trouble.

[LanceM]

Gee I didn't think the 5 minutes it took to make the adapter much of a bother

Just kidding

If you don't have a welder then buying one is the way to go. That's one of those items I never looked to see if they sold! I've made so many over the years I think I have one that will about fit anything. Always seem to have old spark plugs laying around and a bag full of fittings, must be something about being handy and cheap, or cheap and handy, or maybe it good that I'm handy because I'm cheap :0

[Bambikiller240]

SUre, if you have the parts and stuff and can weld, it is cheaper, and the way to go; but not all of us have welding equipment, and/or air fittings lying around. One is no better than the other, just that one or the other would be easier for different folks.

Different strokes for Different Folks

[Ed]

Like Lance said I wouldn't want anything remaining inside the combustion chamber either. If you do use the tubing make sure you use atleast a 10 inch piece. I use a piece of 1/4" fuel line. Feed it through the sparkplug hole towards the valve to be worked. Rotate the piston to secure the tube. To free the keepers I compress the spring then I tap the top of the valve stem with the plastic handle of a screw driver until it breaks free. Then if the screwdriver has a magnetic tip you can use that to retrieve the keepers.:classic:

[keppley]

I have just completed what you are trying to do... Get the type of valve spring compressor that uses the cam as a leverage point. Put enough pressure on the spring to allow the rocker arms to be removed, then...Use a compression tester fitting (minus the needle) hooked to compressed air on a cylinder that has both valves in the closed position. Push down on the spring compressor, remove the keepers and springs, and finally, replace the seals.

[280zx Fever]

you need to take the head off to do it properly sorry guys but when you push down on the valve spring what happens ! the whole valve moves! and you would need to put something into the cylinder to stop it moving.

Dont bother just replacing the valve stems do it properly the first time.