Engine: Replace valveseals with heads on engine...

[Noxnabaker]

Maby I'm annoying someone now, since the engine is a mopar...?
If so, just remove this post!
I've cleaned the roller tappets & am now replacing gaskets & seals but since it's such a good running engine as it is without any smoke or noise, I don't wanna lift the heads but some of the rubbers inside the springs are lose (but not to hard yet) so I wanna replace them without removing the heads!
So now I'm hoping someone can give me a tip on how to do just that; replacing the valve-seals without lifting the heads.

Hoping for GOOD helpful answers...
(The engine pictured is not the one I'm gonna use (way to sludgy), it's just to show how it looks.)

[r1lark]

Nox, you can get an adapter that screws into the spark plug hole, to hook a compressed air hose to. This pressurizes the cylinder and keeps the valve shut while you remove the valve spring. You can then replace the valve seal, reinstall the valve, and move onto the next valve.

[Noxnabaker]

Thanx Paul, I also just got a tip from Jeff involving feeding a rope into the sparkplug hole & cranking up the piston, this is fun & interesting!

[doofus]

Believe Lisle makes the single spring compressor that works.once spring is compressed a sharp rap on the retainer will release it from the valve stem locks. air pressure in cyl is neater than rope. Luck Doofus

[JoeHall]

I have done the rope trick several times, and it works great. I use rope about 5/16" in diameter, and flexible to easily feed through the hole. First, whack the spring collars a couple of times with a brass drift, to unfreeze the keepers. Then, put the piston on the bottom, feed rope in till it is full (usually about 10'), then rotate the motor till it tightens up a bit, but not real tight. Replace the valve seals, then rotate the motor about 1/4 turn and remove the rope. Repeat seven more times.

[Noxnabaker]

I looked at it today, no time to do it thou, & the outlet valvestems I can even reach with a grip to just hold them from there.
The oilpan is also of now so it's easy to see where the pistons are & where to start.
Living on an old farm where the owner was 93 years old & didn't maintain much keep one busy...

[Colgate Studebaker]

Doofus is right, there is a single spring compressing tool by Lisle, I have one and have used it several times over the years. The rope method is good, but I prefer the compressed air method. The Lisle tool is a little awkward to use, but with caution/patience it works well. I'm not a big fan of the small ring type valve seals, much prefer umbrellas or teflon pc type. The pc seals require the valve guide to be machined for them to fit, so you won't be using those. Best of luck, Bill.

[Corley]

Just did this on the Avanti engine, and I did use the compressed air method. Was really easy to do it that way. (The rope method has a big disadvantage. You want the cam to NOT be lifting either of the valves while doing this operation. When using the rope method, this is only true on every other rotation, so after feeding the rope in, a pain itself, you need to make sure you rotate it the right way.) I've done both ways in the past, and rope will take a lot longer than air.

THE CASO METHOD:
I have several valve spring compressors, but I did not have a valve spring compressor that would work well with the Studebaker engine, (Had one, I think someone "borrowed it"), so I just used a hunk of flat steel, 1/4" thick, 1.25" wide, 2' long, and drilled a hole in it about 3-4" from one end for the valve stem to protrude through. Another smaller hole right at that same end, where I bolted on a piece of chain, only about 5" long, which I then bolted to an intake bolt hole. (Select a link that keeps the metal bar pretty level with the top of the valve stem.) This let's the metal bar be used as a lever to push down the spring, and you can then pop the keepers out, let off the pressure and lift the spring off the valve stem. The air keeps the valve securely in place. Slip on the new seal, use the "tool" again to compress the spring, slip the keepers back in and move on the next one.. The only engine rotation done was to make sure the valves were not being lifted by the cam while performing the operation. I DID wind up enlarging the hole for the valve stem to about 5/8", and then using a 1" drill to open the top part of it just to make it easier to access the keepers, but that is not really necessary. Whole operation took less than 1 hour. Don't forget to torque the head bolts through the rocker stands when you re-install them...

By the way, my old seals were mostly just gone or just the outer rings left, after 68k miles on the engine, but after 54 years, what do you expect?

PS Be sure to check all around the heads to get all the little chunks of the old seals out of there, as being rubber/plastic/neoprene/whatever they tend to break up and chucks are everywhere. Lot's of that broken seal junk in the pan on mine as well.

PS/2 I have the right tool now from NAPA to hook the air hose to a spark plug hole. It came as part of a compression test tool. However, I remember before I got that, making a tool using a spark plug extender, and some brass fitting from the junk drawer that would just about screw into it. That fitting had 1/4" pipe on the other end so easily adapted to a quick disconnect for the air hose. Another CASO method for sure, but worked well.

[Noxnabaker]

This is sure get'n interesting, please more different methods & pictures too!

[Larry.s]

Hi I can't get my valve spring compressor to stay on it pops off .

[gordr]

How can the cam be lifting the valves if you have the rocker shafts off? I much prefer the rope trick because it is QUIET. No constant hissing, and no air hose in the way. And no way you can "lose" a valve, if you should accidentally push down hard on it and break the air seal.

[StudeRich]

I don't understand WHY anyone would even try to disassemble a Valve with the Piston DOWN!

The Rope is just a waste of time, and can get stuck under the Valve.

[gordr]

No, Rich, you have all the plugs out, and the rocker shafts off, so all valves are closed. Feed the rope into the cylinder you are working on, and bring the piston up gently by hand-turning the engine. It is very easy to do, and safe, and Quiet.

[wittsend]

Have done the rope process with great success. It is actually less time consuming than the compressor method. And frankly I had more confidence in the rope that the compressor method not leaking. I did this on a Mopar 318 LA engine and like you I had the rocker shaft/arms removed. I used the spring compressor that double hooks over the shaft and pushes down on the retainer. But wait..., the shaft is removed. A short piece of PVC pipe with mounting holes did the job.