Valve seals lifting off?
Thread Starter
Drifting
Joined: Jan 2004
Posts: 1,736
Likes: 2
From: Broken Arrow Oklahoma
St. Jude Donor '09
Valve seals lifting off?
LS3
Aftermarket comp grind
921 springs
Comp seals
Installed professionally
Lost one seal (made it into the pan) Found the metal during an oil change. ugly mess
I installed a new set of blue Viton seals and now 3 seals are against the retainers. I inspected one seal so far and it has a small chip of rubber missing from the top edge of the seal. Is it possible the inner spring is hitting the seal?
Any suggestions?
Aftermarket comp grind
921 springs
Comp seals
Installed professionally
Lost one seal (made it into the pan) Found the metal during an oil change. ugly mess
I installed a new set of blue Viton seals and now 3 seals are against the retainers. I inspected one seal so far and it has a small chip of rubber missing from the top edge of the seal. Is it possible the inner spring is hitting the seal?
Any suggestions?
Thread Starter
Drifting
Joined: Jan 2004
Posts: 1,736
Likes: 2
From: Broken Arrow Oklahoma
St. Jude Donor '09
Yes sir! They were installed seated to the guide both times. I even cleaned the guides and only oiled the tip of the valve stem.
Cam specs unkown. G6x3 921 spring/seal kit Stock LS3 head.
Cam specs unkown. G6x3 921 spring/seal kit Stock LS3 head.
Burning Brakes
Joined: Oct 2005
Posts: 1,007
Likes: 0
From: Rockwall TX
Here's the specs. it dont say they are for Ls3,i'll call my machine shop tomarrow and see what installed height is in a ls3. ID is what you want to measure also.
http://www.compperformancegroupstore...de=GEN3Springs
http://www.compperformancegroupstore...de=GEN3Springs
Thread Starter
Drifting
Joined: Jan 2004
Posts: 1,736
Likes: 2
From: Broken Arrow Oklahoma
St. Jude Donor '09
Here's the specs. it dont say they are for Ls3,i'll call my machine shop tomarrow and see what installed height is in a ls3. ID is what you want to measure also.
http://www.compperformancegroupstore...de=GEN3Springs
http://www.compperformancegroupstore...de=GEN3Springs
Thread Starter
Drifting
Joined: Jan 2004
Posts: 1,736
Likes: 2
From: Broken Arrow Oklahoma
St. Jude Donor '09
921 I.D. is .655
PAC makes this single spring.
Outside Dimension:1.290
Inside Dimension: .885
Max Coil Bind: 1.080
Recommended Installed Height: 1.800
Max Rated Lift: .650
I am not sure that the spring is the solution. I hope its that easy?
PAC makes this single spring.
Outside Dimension:1.290
Inside Dimension: .885
Max Coil Bind: 1.080
Recommended Installed Height: 1.800
Max Rated Lift: .650
I am not sure that the spring is the solution. I hope its that easy?
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Burning Brakes
Joined: Oct 2005
Posts: 1,007
Likes: 0
From: Rockwall TX
Pull your springs and take some pics.measure the boss that the seal press's onto,measure the seal OD installed. Measure the seal ID.a new one, you'll figure it out. most important though. measure your lift on the spring,just rotate the motor.measure installed height,then compressed.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
I've had so many people PM me with this issue and when I got the heads from them, I saw they werent seated properly when they swore they did it right. I used new vitons and returned the heads never to hear anything went wrong from then on.
+1 for a pic of the installed seal.
The installed heights with 921 springs on stock heads (no valve job) is 1.74 due to the .060" hardened seat. Anyone installing them should be aware that the biggest cams out there that are over .640 lift are not going in on a 1.74 installed height. So went the spring says .650" max lift, they mean on a 1.8 installed height.
Installed heights are 1.74 - 1.08 coil bind = .660 so if the lift is .640, youre within .020" of coil bind when your safety margin is .060". This is one reason I dont use crazy lift. There is a comfort zone in the specs but keep in mind that if youre doing these things on your own, you really need to be checking with a valvespring height micrometer.
+1 for a pic of the installed seal.
The installed heights with 921 springs on stock heads (no valve job) is 1.74 due to the .060" hardened seat. Anyone installing them should be aware that the biggest cams out there that are over .640 lift are not going in on a 1.74 installed height. So went the spring says .650" max lift, they mean on a 1.8 installed height.
Installed heights are 1.74 - 1.08 coil bind = .660 so if the lift is .640, youre within .020" of coil bind when your safety margin is .060". This is one reason I dont use crazy lift. There is a comfort zone in the specs but keep in mind that if youre doing these things on your own, you really need to be checking with a valvespring height micrometer.
Thread Starter
Drifting
Joined: Jan 2004
Posts: 1,736
Likes: 2
From: Broken Arrow Oklahoma
St. Jude Donor '09
What would be the approxiamte lift on a ls3 cam that gets you in the 490rw range? I know this is a toss up but there are advertised cams out there that are being used. I will buy an valvespring height micrometer today.
Tech Contributor
Joined: Mar 2003
Posts: 12,094
Likes: 197
From: Colorado Springs, CO
St. Jude Donor '08-'09-'10-'11
LSL can be .630
LSK can be .646
These are really big lift after a 234 intake lobe.
My 230/234 is .612 lift on the intake side with an XFI lobe.
