Valve spring question
Thread Starter
Racer
Joined: Apr 2015
Posts: 415
Likes: 17
From: Virginia
Valve spring question
What is the max lift of the ls2 springs? I’ll be adding new rocker arms and am looking to install 1.8 or 1.85. Looking into reviews the 1.85 can get up to 0.6 lift. I am assuming I should upgrade the springs… will 0.6 be enough or should I go higher? Any cons to adding a higher lift spring?
Advanced
Joined: Apr 2009
Posts: 52
Likes: 2
I always heard going from.1.7 to 1.8 added about 40 to your lift specs..so a stock 520 lift ls2 cam..would essentially be a 560 lift? Just spit balling things I've read not a pro..how are you gonna get around possible pushrod length difference or valve cover clearance issues using 1.8? I looked into this awhile back and could never sort it all out lol
Le Mans Master
Joined: Dec 2005
Posts: 6,999
Likes: 1,685
From: Southeast TX
Divide the valve lift of your current cam by 1.7. Multiply the result by 1.8 or 1.85 (depending on which ratio you choose) to get the ending valve lift. Choose a valve spring that is comfortable with that much lift.
Race Director
Joined: Mar 2011
Posts: 13,262
Likes: 3,151
From: SW Florida
2021 C6 of the Year Finalist - Modified
Want to know what your valve lift will be going from a 1.7 ratio rocker arm to a 1.8 ratio rocker arm ... Here is your calculator:
http://www.wallaceracing.com/rockercalc.php
You will see that it increases the lift approx .032" (32 thousands of an inch)
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Your stock valve springs are safe up to about .550" lift ... You would be better off replacing them with a set of PAC 1218 beehive single springs. These springs are safe up to .600" valve lift and are a drop-in replacement.
As far as needing a different length pushrod ... You should be able to use the stock length pushrods and maintain the correct lifter preload.
Here is a set of nice Comp Cams 1.8 ratio rocker arms for the LS2 and LS3 engine. These will be a drop-in 'full roller' replacement for your stock 1.7 ratio rocker arms ... Comp Cams P/N: 1678-16
http://www.wallaceracing.com/rockercalc.php
You will see that it increases the lift approx .032" (32 thousands of an inch)
_______________________________
Your stock valve springs are safe up to about .550" lift ... You would be better off replacing them with a set of PAC 1218 beehive single springs. These springs are safe up to .600" valve lift and are a drop-in replacement.
As far as needing a different length pushrod ... You should be able to use the stock length pushrods and maintain the correct lifter preload.
Here is a set of nice Comp Cams 1.8 ratio rocker arms for the LS2 and LS3 engine. These will be a drop-in 'full roller' replacement for your stock 1.7 ratio rocker arms ... Comp Cams P/N: 1678-16
