LS7 lifters, trying to get facts straight
10-14-2009, 09:32 PM
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LS7 lifters, trying to get facts straight I am about to install some LS7 lifters and am wanting to verify what I have read. I also ordered a PR checker.
So, if the lifter cup is at its highest point, insert the checker to 0 lash, then take that reading + desired preload and viola, PR length acquired...?
I am also confused on a good preload, is this b/w .060 and .100? With the lower(.060) consisting of a noisier valve train compared to the higher(.100)?
Now when my LS7 lifters come, will they be bottomed out or at the highest point, or somewhere in between? How do I get them where I need them?
Do I need to soak my new lifters before install? Will this effect lifter preload?
I have read many a threads and have actually confused myself, haha
So, if the lifter cup is at its highest point, insert the checker to 0 lash, then take that reading + desired preload and viola, PR length acquired...?
I am also confused on a good preload, is this b/w .060 and .100? With the lower(.060) consisting of a noisier valve train compared to the higher(.100)?
Now when my LS7 lifters come, will they be bottomed out or at the highest point, or somewhere in between? How do I get them where I need them?
Do I need to soak my new lifters before install? Will this effect lifter preload?
I have read many a threads and have actually confused myself, haha
10-15-2009, 12:41 AM
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Cup should be at the highest point. Soak them in oil for a few hours before install. As for measuring PR length, get a checking spring as it wont compress the plunger. It would also help if you got adjustable rockers, but that's a whole different can of worms.
10-15-2009, 10:37 AM
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If you use a stock lifter with shims won't that give you the PR length for a stock lifter? He needs the the PR length for a LS7 lifter right? I only ask because I'm checking my PR length right now.
10-15-2009, 10:49 AM
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this is what I am looking for, a process where I only install lifters/heads once
Soak lifters
Install lifters and trays
Install heads/gaskets/bolts
Torque down
Insert PR checker
Install rocker, torque to 22 ft/lbs
Check PR length
Get proper PRs
Uninstall rockers
Remove PR checker
Install correct PRs
Reinstall Rockers @ 22ft/lbs
DONE, rest assured that everything valvetrain geometry is correct
Anyone have a procedure for this that doesn't install modifying lifters or torquing the heads more than once?
Soak lifters
Install lifters and trays
Install heads/gaskets/bolts
Torque down
Insert PR checker
Install rocker, torque to 22 ft/lbs
Check PR length
Get proper PRs
Uninstall rockers
Remove PR checker
Install correct PRs
Reinstall Rockers @ 22ft/lbs
DONE, rest assured that everything valvetrain geometry is correct
Anyone have a procedure for this that doesn't install modifying lifters or torquing the heads more than once?
