Valve seals replacement help
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
Valve seals replacement help
I'm getting ready to do the valve seals this weekend on my L98. I'll probably use the rope method. I've done a lot of reading (HERE appears to be a good guide). In there, I also see that rocker arms, springs, and ball/pivots should be replaced. Is that all true? I want to keep this job simple so that I can actually get it done...I'm already nervous enough because it sounds like it's easy to really screw something up if you're not careful. I'll try to take photos as I go to help the next guy out.
Team Owner
Joined: Jul 2004
Posts: 28,469
Likes: 3,288
From: Hartford WI
I personally never cared for anything in my cylinder but that's me. I set the TDC on #1 and that ensures the piston stops the valve dropping anywhere. Do that cylinder and move it to #8 and repeat. Then 4, 3, 6, 5, 7, 2.
If you feel froggy, clean up the valve cover and you can use roller rockers and I'd check the pushrods. Or take off the intake for the lifters.
If you feel froggy, clean up the valve cover and you can use roller rockers and I'd check the pushrods. Or take off the intake for the lifters.
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
I'll probably just keep it as simple as possible.
Is it true that you should use the intake seals for exhaust as well? O'Reilly's has two different part numbers for them and I figured the exhaust has to be more heat-resistant, right?
Is it true that you should use the intake seals for exhaust as well? O'Reilly's has two different part numbers for them and I figured the exhaust has to be more heat-resistant, right?
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
I'd stick with the factory "umbrella" style seals on the exhaust valves. The exhaust ports don't have the high vacuum conditions that the intake ports experience.
Melting Slicks
Joined: Jan 2014
Posts: 2,192
Likes: 381
From: Lunenburg MA
Since #1 and #6 are at TDC at the same time, you can do those two without rotating the engine. Then rotate 90 deg. to #8 and #5, then #4 and #7, then #3 and #2.
I'd stick with the factory "umbrella" style seals on the exhaust valves. The exhaust ports don't have the high vacuum conditions that the intake ports experience.
I'd stick with the factory "umbrella" style seals on the exhaust valves. The exhaust ports don't have the high vacuum conditions that the intake ports experience.
I like the compressed air method, but either of the ways discussed works.
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
Thanks for all the information-when I put this back together, do I need to do any adjustment to the valves? Or is it just tighten the rockers back down and you're done?
Safety Car
Joined: May 2001
Posts: 4,757
Likes: 1,647
From: Fairfax Virginia
Hello again Bfenty!
It will go very smoothly using the rope method you have chosen. Positive Mental Attitude and it will be a breeze for you!
Have all the parts and tools handy and within reach and you will make the job easier on yourself. Not to forget one's favorite beverage within reach as well...
While Dad is working on the Corvette there is a No-Kid Zone for 5 yards around Dad's Corvette. No interrupting Dad in the middle of the cylinder head
We are all here to help you and learn as you go! It will go just fine as you are a good planner and You are READY to DO this!
It will go very smoothly using the rope method you have chosen. Positive Mental Attitude and it will be a breeze for you!
Have all the parts and tools handy and within reach and you will make the job easier on yourself. Not to forget one's favorite beverage within reach as well...
While Dad is working on the Corvette there is a No-Kid Zone for 5 yards around Dad's Corvette. No interrupting Dad in the middle of the cylinder head
We are all here to help you and learn as you go! It will go just fine as you are a good planner and You are READY to DO this!
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Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
really? I mean, I've just never done valve work. I'll check the FSM but I'm really new to this, that's why I'm asking for help...
Le Mans Master
Joined: Aug 2017
Posts: 6,941
Likes: 1,490
From: New Jersey
Hey man. Just wanted to let you know I didn't forget you... well I did a little. But uh, I actually looked in my tool box a few weeks back and the seals I still have are actually for a pontiac 400, not a sbc. On top of that a few were crushed and I sort of just forgot to update you... so my bad. 
As far as not losing a valve, the way I was told by my friend is to run compressed air in the cylinder you're not going to work on. That'll put it at BDC. The 2 cylinders 180 degrees away from that one will now be at TDC. Then there's no guessing with degrees of rotation from the balancer.
As far as not losing a valve, the way I was told by my friend is to run compressed air in the cylinder you're not going to work on. That'll put it at BDC. The 2 cylinders 180 degrees away from that one will now be at TDC. Then there's no guessing with degrees of rotation from the balancer.
Team Owner
Joined: Jul 2004
Posts: 28,469
Likes: 3,288
From: Hartford WI
Since #1 and #6 are at TDC at the same time, you can do those two without rotating the engine. Then rotate 90 deg. to #8 and #5, then #4 and #7, then #3 and #2.
I'd stick with the factory "umbrella" style seals on the exhaust valves. The exhaust ports don't have the high vacuum conditions that the intake ports experience.
I'd stick with the factory "umbrella" style seals on the exhaust valves. The exhaust ports don't have the high vacuum conditions that the intake ports experience.
Team Owner
Joined: Jul 2004
Posts: 28,469
Likes: 3,288
From: Hartford WI
Hey man. Just wanted to let you know I didn't forget you... well I did a little. But uh, I actually looked in my tool box a few weeks back and the seals I still have are actually for a pontiac 400, not a sbc. On top of that a few were crushed and I sort of just forgot to update you... so my bad.
As far as not losing a valve, the way I was told by my friend is to run compressed air in the cylinder you're not going to work on. That'll put it at BDC. The 2 cylinders 180 degrees away from that one will now be at TDC. Then there's no guessing with degrees of rotation from the balancer.
As far as not losing a valve, the way I was told by my friend is to run compressed air in the cylinder you're not going to work on. That'll put it at BDC. The 2 cylinders 180 degrees away from that one will now be at TDC. Then there's no guessing with degrees of rotation from the balancer.
Le Mans Master
Joined: Aug 2017
Posts: 6,941
Likes: 1,490
From: New Jersey
because aside from cylinder #1, how do you really know if the one you're working on is at TDC (unless you have a 360 degree marked balancer). If you force one to BDC with air, the twin on the crank will 100% certain be at TDC. For example, 1 at BDC, 7 at TDC. 3 at BDC 5 at TDC. Removes all the guess work on where each piston is because the one filled with air will most definitely be at BDC.
Team Owner
Joined: Jul 2004
Posts: 28,469
Likes: 3,288
From: Hartford WI
because aside from cylinder #1, how do you really know if the one you're working on is at TDC (unless you have a 360 degree marked balancer). If you force one to BDC with air, the twin on the crank will 100% certain be at TDC. For example, 1 at BDC, 7 at TDC. 3 at BDC 5 at TDC. Removes all the guess work on where each piston is because the one filled with air will most definitely be at BDC.
Thread Starter
Drifting
Joined: Mar 2017
Posts: 1,897
Likes: 165
From: Nashville TN
2017 C4 of Year Finalist
because aside from cylinder #1, how do you really know if the one you're working on is at TDC (unless you have a 360 degree marked balancer). If you force one to BDC with air, the twin on the crank will 100% certain be at TDC. For example, 1 at BDC, 7 at TDC. 3 at BDC 5 at TDC. Removes all the guess work on where each piston is because the one filled with air will most definitely be at BDC.
@84 4+3 thanks for letting me know. I went and bought felpros today, I appreciate you being willing to share though.
Racer
Joined: Feb 2019
Posts: 397
Likes: 29
From: Jackson, mi
this is a job that you really need to know what you are doing, you should be watching video's and a lot of them. or consider just pulling the heads off and be done with it, clean the valves and carbon depsoits while you have them off. if you drop a valve. you will be taking them off regardless. just my 2 cents for what it's worth
Last edited by bud40oz; Apr 17, 2020 at 09:04 PM.
Team Owner
Joined: Jul 2004
Posts: 28,469
Likes: 3,288
From: Hartford WI
this is a job that you really need to know what you are doing, you should be watching video's and a lot of them. or consider just pulling the heads off and be done with it, clean the valves and carbon depsoits while you have them off. if you drop a valve. you will be taking them off regardless. just my 2 cents for what it's worth
Racer
Joined: Feb 2019
Posts: 397
Likes: 29
From: Jackson, mi
yeah that is quite a bit different from removing them and throwing em on a bench on the garage but okay. my point i was making to him is he is asking the very most basic questions of the job and just removing them and doing the job off vehicle my be a better option. I wish i had your money though, geez. i am poor. i HAVE to do stuff like that myself
Team Owner
Joined: Jul 2004
Posts: 28,469
Likes: 3,288
From: Hartford WI
yeah that is quite a bit different from removing them and throwing em on a bench on the garage but okay. my point i was making to him is he is asking the very most basic questions of the job and just removing them and doing the job off vehicle my be a better option. I wish i had your money though, geez. i am poor. i HAVE to do stuff like that myself