There Must Be a Trick to This....
#1
11-16-2009, 06:14 PM
There Must Be a Trick to This....
Since I have my valve covers off my 4.3 and will be changing at least one lifter, I thought I would finally change the valve stem seals and stop the cloud of smoke at every startup (hopefully).
Got it all set up and started to work on #1 exhaust with the valve spring compressor. No joy.
Can't seem to compress it enough to expose the keepers. After an hour of trying I moved to the intake valve and got that one off in no time. Back to the exhaust. Still no good. For the heck of it I went to #3 exhaust and tried that. Same luck. If I can get the compressor to latch onto the spring and hold (keeps want to pop off) it doesn't seem to compress enough before it bottoms out on the shield.
I know this isn't rocket science but I have tried two different compressors with the same result. Can't find anyone around here that sells the level style compressor.
I would appreciate any insight....
Got it all set up and started to work on #1 exhaust with the valve spring compressor. No joy.
Can't seem to compress it enough to expose the keepers. After an hour of trying I moved to the intake valve and got that one off in no time. Back to the exhaust. Still no good. For the heck of it I went to #3 exhaust and tried that. Same luck. If I can get the compressor to latch onto the spring and hold (keeps want to pop off) it doesn't seem to compress enough before it bottoms out on the shield.I know this isn't rocket science but I have tried two different compressors with the same result. Can't find anyone around here that sells the level style compressor.
I would appreciate any insight....
#3
11-17-2009, 07:14 AM
Thanks for the reply. I have a length of nylon rope in the cylinder compressed by the piston. I tried compressed air but the adapter I have does not allow me to snug up the connection in the spark plug hole.
#4
11-17-2009, 06:10 PM
Well, I finally got the exhaust spring off. Found that the valve stem was sticking to the spring AND I did not have it compressed enough with the nylon rope.
Started on #1 and looking at how difficult it was to pull, I am not looking forward to #5 and #6. But such is life.
I have a kit with 12 "O" rings and 6 positive seals. So only "O" rings on the exhaust although I have seen a kit for exhaust "seals". Any thoughts on that versus just the "O" rings?
Started on #1 and looking at how difficult it was to pull, I am not looking forward to #5 and #6. But such is life.
I have a kit with 12 "O" rings and 6 positive seals. So only "O" rings on the exhaust although I have seen a kit for exhaust "seals". Any thoughts on that versus just the "O" rings?
#5
11-17-2009, 08:20 PM
I have always used the umbrella style oil seals for all. I haven't had the pleasure to do it on a modern engine though... Most all of them have been on older SBC & BBC.
I wasn't sure if you could get enough support with rope in the cylinder. You could have hit each spring retainer with a hammer prior to trying to putting the spring compressor on them. That should be enough to free the retainer from the valve stem.
I wasn't sure if you could get enough support with rope in the cylinder. You could have hit each spring retainer with a hammer prior to trying to putting the spring compressor on them. That should be enough to free the retainer from the valve stem.
#6
11-18-2009, 09:43 AM
Replacement Valve Stem Seals
Found some info about these different types of seals. Although they reference the "Z" they are the same part numbers as the "W". Sometimes I get ****
about trying to understand the why of "why" of things. Anyway, here is the paraphrased info from the post by TyMeUp on syty.net:
The final word on valve stem seals... I hope.
about trying to understand the why of "why" of things. Anyway, here is the paraphrased info from the post by TyMeUp on syty.net:The final word on valve stem seals... I hope.
4.3L 262 OHV TURBO V6 (CHEVROLET), 4" BORE - 1991-93 - L/D TRUCK VIN CODE "Z" 1991-93
VALVE STEM SEAL SET - YEARS - PART NO. -- DESCRIPTION
Valve Stem Seal Set -- 93-91 -- SS72876 --- Exh,; Premium valve stem
seals incl.
Valve Stem Seal Set -- 93-91 -- SS72530 --- Int.; Premium valve stem
seals incl.
To get an accurate description of these seal sets, I called the Fel-Pro Tech Line (1-800-325-8886) as listed in the new catalog. The tech that I spoke with described the #SS72530 set as Viton 'positive' seals and the #SS72876 as Nylon 'umbrella' seals.
When I asked why Fel-Pro went with the umbrella style instead of the positive type, the answer was that their engineers determined that this seal would hold up better and that the exhaust seals didn't have to work as hard as intake seals (not as much vacuum on the exhaust side).
Next, I asked if he could recommend a 'positive' seal for the exhaust stems. After checking his listings, he came back with #SS72711. This set was described as eight Viton 'positive' seals.
Finally, I asked if I should use the stock O-Ring seals along with the new positive seals. The answer: "There is no reason why you shouldn't…they can only help control the oil flow to the new seals, making their job easier."
The OEM Chevrolet 'O-Ring' valve stem seal design has been used since 1955. It works by sealing the valve spring retainer to the valve stem, preventing oil from running through the split locks, down the stem and into the valve guide. When used with the upside-down cup shaped 'oil shedder' on top the valve spring, it turns the top of the valve spring assembly into a large 'umbrella' seal. This sealing system works well until 75,000 miles or so. At that point valve stem-guide wear and increased blow-by pressure begins to overwhelm this 'non-positive' sealing system.
And here is a link to the Fel-Pro site with more info:
https://extranet.federal-mogul.com/f...als/index.html
VALVE STEM SEAL SET - YEARS - PART NO. -- DESCRIPTION
Valve Stem Seal Set -- 93-91 -- SS72876 --- Exh,; Premium valve stem
seals incl.
Valve Stem Seal Set -- 93-91 -- SS72530 --- Int.; Premium valve stem
seals incl.
To get an accurate description of these seal sets, I called the Fel-Pro Tech Line (1-800-325-8886) as listed in the new catalog. The tech that I spoke with described the #SS72530 set as Viton 'positive' seals and the #SS72876 as Nylon 'umbrella' seals.
When I asked why Fel-Pro went with the umbrella style instead of the positive type, the answer was that their engineers determined that this seal would hold up better and that the exhaust seals didn't have to work as hard as intake seals (not as much vacuum on the exhaust side).
Next, I asked if he could recommend a 'positive' seal for the exhaust stems. After checking his listings, he came back with #SS72711. This set was described as eight Viton 'positive' seals.
Finally, I asked if I should use the stock O-Ring seals along with the new positive seals. The answer: "There is no reason why you shouldn't…they can only help control the oil flow to the new seals, making their job easier."
The OEM Chevrolet 'O-Ring' valve stem seal design has been used since 1955. It works by sealing the valve spring retainer to the valve stem, preventing oil from running through the split locks, down the stem and into the valve guide. When used with the upside-down cup shaped 'oil shedder' on top the valve spring, it turns the top of the valve spring assembly into a large 'umbrella' seal. This sealing system works well until 75,000 miles or so. At that point valve stem-guide wear and increased blow-by pressure begins to overwhelm this 'non-positive' sealing system.
And here is a link to the Fel-Pro site with more info:
https://extranet.federal-mogul.com/f...als/index.html
#8
11-19-2009, 11:00 PM
What size diameter and roughly how long is the rope you are using? I put on my plug adapter on the first cylinder and it's leaking too much air to hold it. My little compressor can't keep up. So I need to use rope now.
#9
11-20-2009, 07:42 AM
Originally Posted by Blazin_Jason
What size diameter and roughly how long is the rope you are using? I put on my plug adapter on the first cylinder and it's leaking too much air to hold it. My little compressor can't keep up. So I need to use rope now.
It is probably just as easy to do the cord as the compressed air and a LOT more secure. Once you feed that amount in, turn the motor to compress it against the valves. Good luck.
#10
11-20-2009, 09:55 AM
I am having the same issue you had. I'm using 3/16's polyester rope but I don't know how much I put in. Probably a good 2-3' at a guess. I will probably pull it out and put some marks on it so I know how much is in there. I don't think I would have any luck getting it to curl into the cylinder. I have been feeding the rope in with a screwdriver. I even gave the springs a couple good taps with a small hammer. Will try again tonight.
edit: Gave it another go and got the keepers off on the first exhaust spring. At least now I know what has to be done. Man our these heads sludgy :S
edit: Gave it another go and got the keepers off on the first exhaust spring. At least now I know what has to be done. Man our these heads sludgy :S
Last edited by Blazin_Jason; 11-20-2009 at 06:51 PM.
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