Hi C5ers... This is my first post in the c5 section... i have a lsx Question about rocker arm preload... i have just recently purchased a ls1 from a 34k mile ws6 trans am with the 460le. i plan on doing a cam and head swap on the motor before i drop it in the vette.. i just read this comment in the ls1 tech {{{{{"There is no lash adjustment on LSx engines. The rocker arms are torqued to 22 ft-lbs, and the pushrod length is what determines the correct lifter pre-load. If you don't change anything in the valve train that would require different length pushrods, then you have nothing to worry about.}}}}} is this true????

my plan is to use the 243 heads and cam from a late year c5 with the light valve train and titanium goodies.. Thanks in advance

Neptune.....

 

Neptune

Well,,,,,,,,,,,,,,,,,,,,,, Your correct. You have a LOT to learn!

If you run TRUE ZO6 heads with hollow sodium filled valves, the push rods will have to be changed as the valves are different lengths than non ZO6 heads.

The ONLY way to be absolutely sure of that correct length push-rods is to use a push rod checker to figure out what you actually need!

If your going thru all the trouble of installing a different cam,, I strongly recommend that you skip the idea just installing the ZO6 cam. There really isn't all that much difference to be worth the tuning and trouble. Get a decent aftermarket cam that will make a marked difference in performance for all your troubles.

There are PLENTY out there that will make you very happy! Make sure that you get the PCM tuned after the cam swap what ever you decide on installing.


BC

 

bill i have lurked in the c5 tech section for a little while before deciding to go ls1. your right i have a ton to learn about these engines.. i really like the idea of the light weight valvetrain that the ls6 has. i currently have a 496 bbc in the car. one of the reasons for the swap is driveability. my goal is {400ish} rear wheel power. and a trq curve that comes in early.

what cam and heads would you recomend??? im glad you chimed in. you seem to be very informed on the ls engines..

Neptune..

Here is a pic of the car that the ls will soon live in

 

p.s ... I also plan on reworking my 2 1/8" Hooker Super Competiton Headers and side pipes .. ls

Neptune

 

I agree I would never use a STOCK Z06 cam--Everyone I know regretted it
For a DD type car weekend racer and NOT having to worry about passing smog on rollers I would get something in the mid .230's @ .050 try to keep the lift below .600 so you don't have to replace the valse springs all the time---As far as LSA -stock is very high like 119-117---The lower the LSAt he more radical the idle-
114 is a nice semi choppy idle and smooth idle around 700-800-
Many choose a 112--sounds very racey and lopes very cool -you'll have to set the idle up higher-- 800-850---ALSO You may need to get a baby stall to acomodate the new cam--as it will be hard to hold the car ar a stoplight with the stock stall when idling above 750

Stock LS6 243 heads are a good choice and an honest 12-15 RWHP above a stock LS1 head--I would absolutely check the pushrod length with a pushrod checker-Installing the rockers with the torquing method as you described is pretty much the only way it can be done with the stock non adjustable rockers--But you can also do it the old way as well by getiing the piston at TDC on the comp stroke and getting the pushrod "just tight" and then going another 1/2 turn on the locking nut--Of corurse this would be with aftermatket rockers that have adjustment nuts--

ALSO :
I would deff make sure you have an LS6 intake maifold worth again another 10-12 RWHP---
Install an LS6 intake valley that re-routes the PCV system-prevents oil from sucking up into the manifold--which LS1's are notorious for--

 

From one old C3 guy to another here you go.