Sorry I'm kinda new to the site, but I've run into a strange problem trying to install a set of LT4 roller rockers on my '97 Z28. Basically, my problem is that when I torque the rocker down to spec (I believe 18ftlbs is what I've read), the spring compresses, which I know isn't right. Most hydraulic lifted rockers need to be zero lashed plus 1/4 - 1/2 turn, right? So why is that EVERYWHERE I've read says to just pop 'em on and torque them to spec??? I realize that the LT4 studs are different, 10mm vs 7/16, I think. Could it be that you run the nuts down to the end of the thread and torque, cause that's what it looks like on the factory rockers. Right now I'm doing the 1/4 turn method and allowing slight movement of the rocker. If I continue this, will I blow up my engine?? I'm trying to get done tonight, so any help with this issue would be greatly appreciated, cause I know you guys know WAY more about it than I do!! Thanks alot!

 

Ummm don't torque down rocker's.. What your currently doing is right... take up the lash and go 1/4 or so.. while the lifter is on the base of the cam lobe..

 

.. unless i'm missing something here. . you don't Torque them to anything. Put them in, tighen rocker nut until you can feel "drag" in the pushrod as you spin it in your fingers, then with reusing stock lifters, give it a 1/2 turn for preload. Thats it. .

There is a special time to do half of them, then do the rest after full turn of crank if you don't run the motor. I'll get you the internet guid i used.. hold on.

 

http://shbox.com/1/4th_gen_tech2.html#adjust_valves

Just use that guide. Shoebox is awsome. And its pretty easy once you start doing it. Took me like 15min.

 

Hey thanks alot!! Just finished all of 'em using the two step method, #1 and #6 TDC. Zero lashed and 1/2 turn for preload. Should be done soon. I think I have to modify the valve covers a little bit to clear the rockers. I still don't understand why I've read to torque them and even found a torque spec, when my better judgement tells me not to.... oh well, tire smoke here we come!!!

 

The hot cam instructions says that after the lash is set, to hold the polylock nut with a wrench and to tighten the polylock setscrew to 15-20 ft lbs. That's probably what you're referring to.

Chris

 

The torque method only applies to stock LT4 rockers and rocker studs.