Advice / pointers on replacing valve seal

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GREEN GHOST

GREEN GHOST

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This weekend (hopefully) I'm going to attempt changing valve seals (cylinder 3 only, engine in car assembled) on my 440. I've never done anything & had a few questions I was hoping members with experience would be able to help out with:

How many psi should i set compressor at to fill cylinder?

Does the cylinder have to be TDC? If so can I just bar the motor over until I see the rocker raise and just start to come down?

What is the torque spec for the rocker assembly when I put them back on?

Can I just use a valve seal install tool to push the seal on the valve stem ? Will it damage the seal again or do I need like a straw / tube

Any additional advice / tips / tricks would greatly appreciated & sorry in advance for the academic questions. I would like to learn & tackle this myself rather than just paying to have it done
 
Also along with the speed master valve seals and a 1 1/4" socket to turn the motor over I bought the tools pictured below. Anything I'm missing for this job?
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Personally, I would use the road trick rather than air pressure.
Back the cylinder down from TDC on the cyl in question. Feed cotton cord into the spark plug hole then bring the cyl back up to tdc. The cord will keep the valves in place, no chance of popping one open, no chance of dropping one into the cyl, no chance of hitting the top of the piston.
 
Dana67Dart said:
Personally, I would use the road trick rather than air pressure.
Back the cylinder down from TDC on the cyl in question. Feed cotton cord into the spark plug hole then bring the cyl back up to tdc. The cord will keep the valves in place, no chance of popping one open, no chance of dropping one into the cyl, no chance of hitting the top of the piston.
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This is the first I'm hearing of that method but if it's safer I'll go that route. . .just normal cord you use & how how much do you feed in ?
 
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Make sure it's big enough in diameter that none of it gets stuck under the valve when you reassemble. ( I get rags stuck between the seat sometimes at work).
There should be a seal installer but i don't believe they're necessary unless the valve tip is rough
If I remember correctly the seals are not difficult to put on if it's a positive seal then just use a socket that is probably around 7/16 or 1/2 inch or whatever works. I do head rebuilding everyday but never changed a seal while the head is still on the engine.
 
The rope/cord trick is ok.....until it gets stuck.

I don't use compressed air either, PITA.

What I have used for years to replace seals/springs is a bent screwdriver! Get the piston close to TDC. Bend an old screwdriver 1.5" from the end about 30*. Poke it through the spark plug hole so that it's tip touches the valve. Some experimentation might be reqd with tip length & angle to suit the cyl head. Reason for piston at TDC is in case the s'driver slips, valve does not fall into cyl & cause a WTF moment...
 
We change a lot of valve valve springs at the dyno. There are many ways to do this.
If you are using the air method you will want an air regulator on the hose. You want just enough air pressure to hold the valve shut and not so much that the air pushes the piston down. Start with about 15 or 20 psi and turn up if needed. The piston will stay up better if the piston is exactly TDC.
Remove the rockers.
You will probably have to break the retainer loose from the locks as they can get stuck. There may be other ways but this is how I do it. Take a small hammer, plastic or brass would be nice but steel will work if you're careful. Tap straight down parallel to the valve stem near the outer edge of the retainer. A few taps should do it. Listen as you tap for a change in sound. You can come back to this step and repeat if it's still stuck.
Plug all the places where a lock could fall into the engine with shop rags.
Install the compressor tool and compress the spring. If the valve wants to open you either need a little more air pressure or the retainer and locks are still stuck.
Push the retainer down past the locks use your fingers or a small magnet to retrieve the locks as you are pushing down.
Let the spring and retainer up and remove from the engine. Replace the seal. Put the spring and retainer back on the head.
The next part can be tricky. When you compress the spring to replace the locks you may notice the retainer is closer to the valve stem on one side than the other. Try to put the lock in the side that is closest to the stem first. Let up just enough to hold that lock in place. If the lock catches on the retainer when you let up just move it over a little and try again. Push back down just enough to slip the last lock in place without the first falling out. lol. Visually compare to another valve to make sure all is in place properly.
hope this helps.
 
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Also you can use a magnet on top of the retainer when you get your spring compressor on the valve it is a helpful tool for keepers
 
92b said:
We change a lot of valve valve springs at the dyno. There are many ways to do this.
If you are using the air method you will want an air regulator on the hose. You want just enough air pressure to hold the valve shut and not so much that the air pushes the piston down. Start with about 15 or 20 psi and turn up if needed. The piston will stay up better if the piston is exactly TDC.
Remove the rockers.
You will probably have to break the retainer loose from the locks as they can get stuck. There may be other ways but this is how I do it. Take a small hammer, plastic or brass would be nice but steel will work if you're careful. Tap straight down parallel to the valve stem near the outer edge of the retainer. A few taps should do it. Listen as you tap for a change in sound. You can come back to this step and repeat if it's still stuck.
Plug all the places where a lock could fall into the engine with shop rags.
Install the compressor tool and compress the spring. If the valve wants to open you either need a little more air pressure or the retainer and locks are still stuck.
Push the retainer down past the locks use your fingers or a small magnet to retrieve the locks as you are pushing down.
Let the spring and retainer up and remove from the engine. Replace the seal. Put the spring and retainer back on the head.
The next part can be tricky. When you compress the spring to replace the locks you may notice the retainer is closer to the valve stem on one side than the other. Try to put the lock in the side that is closest to the stem first. Let up just enough to hold that lock in place while you place the other lock oppsite it. If the lock catches on the retainer when you let up just move it over a little and try again. Push back down just enough to slip the last lock in place without the first falling out. lol. Visually compare to another valve to make sure all is in place properly.
hope this helps.
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Thank you for taking the time to write such a detailed response. Probably a stupid question but is the cylinder at tdc when the rocker raisers and just starts going down ? Also what's the typical torque spec for the rockers when I'm bolting them back to the head ?
 
iirc 35ft/lbs is spec'd but ITS WRONG! Use more like 17 ft/lbs. Dont go crazy. TDC is either both valves are closed or both are on their ramps. There are 2 TDC's in the 4 stroke. It can be noted by the keyway in the crank shaft (points right up #1 crank throw) if you can get bolt out and put a mirror down there or just look at distributor and see when rotor is pointing towards #1, that will be TDC of power stroke of #1.
 
pishta said:
iirc 35ft/lbs is spec'd but ITS WRONG! Use more like 17 ft/lbs. Dont go crazy. TDC is either both valves are closed or both are on their ramps. There are 2 TDC's in the 4 stroke. It can be noted by the keyway in the crank shaft (points right up #1 crank throw) if you can get bolt out and put a mirror down there or just look at distributor and see when rotor is pointing towards #1, that will be TDC of power stroke of #1.
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Good info thanks . . .now how do you tell or differentiate which cylinder the piston is tdc in ?
 
If the distributor is in and it ran, just look to the rotor position. If not, remove all the plugs and turn the crank by hand with your thumb over the #1 spark plug hole, when it starts to push air, youll know its on the compression stroke. You can put a popsicle stick in there and watch it rise while you turn the crank by hand. Piston stops are better: thread it in, and run the piston up BY HAND with the crank until it touches stop and mark the balancer at the TDC pointer, now run the crank the opposite way BY HAND and touch the stop again, mark the balancer at TDC pointer again. remove piston stop and turn crank so TDC pointer is exactly 1/2 way between the 2 marks (shortest distance) that is TDC of that piston. All the rest are 90 from that point. Your balancer should be marked very close to this on #1 (driver side front cylinder) if not dead on. If its a few degrees off, your balancer may have moved as that ring is on bonded rubber that can seperate over time and cause the ring to shift.
 
pishta said:
If the distributor is in and it ran, just look to the rotor position. If not, remove all the plugs and turn the crank by hand with your thumb over the #1 spark plug hole, when it starts to push air, youll know its on the compression stroke. You can put a popsicle stick in there and watch it rise while you turn the crank by hand. Piston stops are better: thread it in, and run the piston up BY HAND with the crank until it touches stop and mark the balancer at the TDC pointer, now run the crank the opposite way BY HAND and touch the stop again, mark the balancer at TDC pointer again. remove piston stop and turn crank so TDC pointer is exactly 1/2 way between the 2 marks (shortest distance) that is TDC of that piston. All the rest are 90 from that point. Your balancer should be marked very close to this on #1 (driver side front cylinder) if not dead on. If its a few degrees off, your balancer may have moved as that ring is on bonded rubber that can seperate over time and cause the ring to shift.
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Got it thanks. I'm gonna check the distributor
 
pishta said:
If the distributor is in and it ran, just look to the rotor position. If not, remove all the plugs and turn the crank by hand with your thumb over the #1 spark plug hole, when it starts to push air, youll know its on the compression stroke. You can put a popsicle stick in there and watch it rise while you turn the crank by hand. Piston stops are better: thread it in, and run the piston up BY HAND with the crank until it touches stop and mark the balancer at the TDC pointer, now run the crank the opposite way BY HAND and touch the stop again, mark the balancer at TDC pointer again. remove piston stop and turn crank so TDC pointer is exactly 1/2 way between the 2 marks (shortest distance) that is TDC of that piston. All the rest are 90 from that point. Your balancer should be marked very close to this on #1 (driver side front cylinder) if not dead on. If its a few degrees off, your balancer may have moved as that ring is on bonded rubber that can seperate over time and cause the ring to shift.
Click to expand...
So to find tdc in cylinder 3 (the one I'm replacing valve seals on) I would go 180degrees from TDC marked on balancer whoch should be cylinder one?
 
more like 270, or back it up 90. You just want the #3 piston in the raised position.
 
pishta said:
more like 270, or back it up 90. You just want the #3 piston in the raised position.
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Ok so line up 0 on damper then back off 90. Got it. . .Thanks for explaining multiple times for me lol
 
Easiest, least fuss. Just stick a rope in and turn the crank to bring it and the piston up against the valve heads, re and re the spring and seal, turn crank backwards a tad and pull out the rope.
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GREEN GHOST said:
This weekend (hopefully) I'm going to attempt changing valve seals (cylinder 3 only, engine in car assembled) on my 440. I've never done anything & had a few questions I was hoping members with experience would be able to help out with:

How many psi should i set compressor at to fill cylinder?

Does the cylinder have to be TDC? If so can I just bar the motor over until I see the rocker raise and just start to come down?

What is the torque spec for the rocker assembly when I put them back on?

Can I just use a valve seal install tool to push the seal on the valve stem ? Will it damage the seal again or do I need like a straw / tube

Any additional advice / tips / tricks would greatly appreciated & sorry in advance for the academic questions. I would like to learn & tackle this myself rather than just paying to have it done
Click to expand...
Why are you only replacing one seal (on #3)? Was it torn or broken? Normally it is best practice to replace all of them at the same time if they are cracking. Once they crack, they often are very brittle and start to fall apart.
 
Ricks70Duster340 said:
Why are you only replacing one seal (on #3)? Was it torn or broken? Normally it is best practice to replace all of them at the same time if they are cracking. Once they crack, they often are very brittle and start to fall apart.
Click to expand...
So far since I've had the car I haven't had any issues at all. The previous owner told me that from time to time the #3 spark plug will get covered in oil and it'll start running rough. He said the #3 valve seals need to be changed. . .I'm hoping it was an install error or something, the engine has about 4k miles on it and was built about 10yrs ago
 
dadsbee said:
Easiest, least fuss. Just stick a rope in and turn the crank to bring it and the piston up against the valve heads, re and re the spring and seal, turn crank backwards a tad and pull out the rope.
View attachment 1715839652 View attachment 1715839653 View attachment 1715839654 View attachment 1715839655 View attachment 1715839656 View attachment 1715839657 View attachment 1715839658
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Wow, thanks so much for posting pictures. That definitely seems much easier than using the air method. My only fear is not having the cylinder high enough or enough rope fed in & the valve just dropping
 
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