Valve stem seals how to?
Thread Starter
Melting Slicks
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Valve stem seals how to?
Ok, just received my new set of valve springs and kit. This is my FIRST time working with valves. What is the proper way to install the parts? Which comes first? Also the new seals - do they go over what my finger is pointing to? Or should that piece be removed? The seal is suppose to go on the bottom of the two rings, correct? The old seals had a cap, do I re-use this cap? or leave it off and just place the retainer in? Thanks...
Tech Contributor
Joined: Aug 1999
Posts: 14,379
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
The viton seals you have bought, aka "Positive Control" (PC) Seals, require that the valve stem guide bosses be machined to match the seal diameter. It appears that your guides have been machined, but you need to verify the diameter and make sure it's correct for your seals. If it's not, you have to remove the heads, disassemble them, and have the valve guide bosses machined.
The PC seals are installed over the valve (make sure you use the plastic "condom" that slips over the valve tip when you install them, or they will get damaged passing over the valve stem grooves) and onto the guide boss. If the bosses are correctly machined, the seals will fit snugly down onto the bosses and seal off any oil from going down the guide. You do not use the standard groove o-ring seal when you have PC seals, so the second groove in the valve stem will be empty.
The "caps" are oil splash shields, used with the stock top stem seals to prevent excessive oil splash onto the valve stems. They're not needed with the PC seals, but many people use them anyway. Deleting them removes a small amount of weight off the valve, which helps a little.
Lars
The PC seals are installed over the valve (make sure you use the plastic "condom" that slips over the valve tip when you install them, or they will get damaged passing over the valve stem grooves) and onto the guide boss. If the bosses are correctly machined, the seals will fit snugly down onto the bosses and seal off any oil from going down the guide. You do not use the standard groove o-ring seal when you have PC seals, so the second groove in the valve stem will be empty.
The "caps" are oil splash shields, used with the stock top stem seals to prevent excessive oil splash onto the valve stems. They're not needed with the PC seals, but many people use them anyway. Deleting them removes a small amount of weight off the valve, which helps a little.
Lars
Thread Starter
Melting Slicks
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Thank you Lars! I feel like I owe you alot. You have helped me tremendously over the past 18 months! I got the kit from Summit. I spoke with them and they said this kit will fit. No modifications required. I do NOT have that "plastic condom" I double checked, there is none. What can I use? Also you said to check the valve stem guide bosses. How would I know if these really fit? Just slide one down and see if it fits snuggly?
Tech Contributor
Joined: Aug 1999
Posts: 14,379
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
It's really important that you have the plastic "condom" protective sleeve to slide over the top of the valve stems before attempting to force the PC seals on. See if your local NAPA store has some of the protector sleeves. Your local automotive machine shop is sure to have some that they'll either give you or sell you - any pro doing head work uses the sleeves (you only need one, unless you damage it, which is why most PC seal kits contain two of them). Jamming the seals down over those valve stem grooves will likely compromise the effectiveness of the new seals.
The seals you bought should be for a specific guide diameter - there are several different diameters available. Simply measure your guides and verify that they really are the diameter that the seals are intended for. You can use a dial caliper to get close, or a micrometer to get exact.
Lars
The seals you bought should be for a specific guide diameter - there are several different diameters available. Simply measure your guides and verify that they really are the diameter that the seals are intended for. You can use a dial caliper to get close, or a micrometer to get exact.
Lars
Last edited by lars; Apr 13, 2012 at 10:37 PM.
Thread Starter
Melting Slicks
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
Ok, the. Plastic "condoms" are hard to find. Napa and the local auto store don't have them. Both say there suppose to be in the kit. Contacted Summit, this was there reply. (The sleeves should not be needed. When looking at the top of the valves where the lock groove is, the bottom of the groove should be tapered/beveled so that the seal is not damaged when installed without the stem sleeve. Thanks, Mike)) So what would you do?
Drifting
Joined: Aug 2005
Posts: 1,372
Likes: 4
From: Springfield VA
Go buy some straws.
I have used some straws, cut to shorter length, to do the same thing. Make sure they are not the super thin cheap ones and not to small/big for the valves.
This is what the real ones look like...
You can see, middle items, its like a short straw with a taper at top so it does not slide to much.
I have used some straws, cut to shorter length, to do the same thing. Make sure they are not the super thin cheap ones and not to small/big for the valves.
This is what the real ones look like...
You can see, middle items, its like a short straw with a taper at top so it does not slide to much.
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Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Might have better luck at a machine shop than parts store.
You may also want to call these guys - I didn't see them on their website, but they're a great source for all tools/items for engine building: http://www.goodson.com/
You may also want to call these guys - I didn't see them on their website, but they're a great source for all tools/items for engine building: http://www.goodson.com/
Melting Slicks
Joined: Aug 2008
Posts: 2,200
Likes: 3
From: Lehigh county Pennsylvania
Your PC (in my case it stands for Perfect Circle brand valve stem seals) seal kit should have included an installation tool along with the condom(s). Mine looks like this and makes sure the seals are seated square and straight.
Thread Starter
Melting Slicks
Joined: Aug 2010
Posts: 2,487
Likes: 10
From: Palm Beach Florida
St. Jude Donor '12
(riski) I just finished placing a cam in my car two weeks ago. The symptoms I had last week (theres a vid I posted) was "POPPING" out the exhaust. It was getting progressively worse. When I did the cam I left in my original springs hoping to get away with it for awhile. Well that didn't happen. So I'm doing this! Oh well, at least I always have you guys and especially Lars to help back me up on all my adventures. LOL.
