Lifter preload on a LS-1
Drifting
Joined: Nov 2002
Posts: 1,776
Likes: 5
From: Midlothian Texas
St. Jude Donor '12-'13-'14-'15-'16
Re: Lifter preload on a LS-1 (corvette4life)
No preload on the stock system. Torque rocker to 22 ft lb.
If the rockers were not removed don't worry about it. :D
If the rockers were not removed don't worry about it. :D
Safety Car
Joined: Nov 1999
Posts: 3,891
Likes: 2
From: Houston, TX
Re: Lifter preload on a LS-1 (corvette4life)
99% of the time, this is not going to be an issue, but there are a few ways in which you can adjust your pre-load on an LS1.
First, you can use a shorter pushrod. You really want to use the pushrod length that will give you the proper valvetrain geometry though.
Second, you can shim your rocker pedestals up a little. We have various sized shims we can use to take a little of the pre-load out.
The easiest way to see how much pre-load you have is to count the amount of turns that is takes from the point in which all slack is taken out of the rocker assembly to the point in which it is tight. The thread pitch for the stock bolt is 1.5mm. Multiply that by the amout of turns and convert to inches.
Good luck, but if you are throwing in a cam from a popular company, I would not worry about this. :chevy
First, you can use a shorter pushrod. You really want to use the pushrod length that will give you the proper valvetrain geometry though.
Second, you can shim your rocker pedestals up a little. We have various sized shims we can use to take a little of the pre-load out.
The easiest way to see how much pre-load you have is to count the amount of turns that is takes from the point in which all slack is taken out of the rocker assembly to the point in which it is tight. The thread pitch for the stock bolt is 1.5mm. Multiply that by the amout of turns and convert to inches.
Good luck, but if you are throwing in a cam from a popular company, I would not worry about this. :chevy
Thread Starter
Racer
Joined: Apr 2002
Posts: 311
Likes: 0
From: Charleston S.C.
Re: Lifter preload on a LS-1 (Chris@SpeedDemon)
Hello Chris,
Thanks for the great info on checking lifter preload on the LS-1. If I need to shim them what do I use? Is it a shim I can get locally?
Thanks
Thanks for the great info on checking lifter preload on the LS-1. If I need to shim them what do I use? Is it a shim I can get locally?
Thanks
Melting Slicks
Joined: Aug 1999
Posts: 3,452
Likes: 3
From: Spring, TX
Re: Lifter preload on a LS-1 (Patches)
If you are using stock lifters, stock rockers, and the heads have not been shaved then 22ftlbs on the rockers is it. I just started this install tonight. Currently tearing everything down.
