I measured for my push rods tonight and its kind of middle of the road. I had the Comp Checker at 10 turns and it jiggled around, moved it to 10.5 and it was tight, 10.25 was tight, a itty witty less and got some movement. So based on what texas speed sells at a .080 pre-load I need a PR thats 7.395. Thats leave me to purchase a 7.400 PR or 7.375. I guess the 7.375 would give me a .060 pre-load.

Go bigger or smaller?

 

IDK, but maybe you can answer a question for me? I have the #1 piston at TDC so the cam is on the base circle. Push the ls7 lifters down to the cam, install PR checker, torque the rocker, and turn the checker till 0 lash. Take the rocker loose to get PR length, then add the preload i want to that correct? I have a 7702 comp checker i think, when it's fully closed how long is it and is each turn 0.050"?

 

What type of lifter??

 

Yes, what lifters are you running is what's really relevant. They have an operating range - ie the LS7 lifters have a lash range of something like 0.040 to 0.080. Below 0.040 the less hydraulic and the more solid they become and as you get over 0.080 you risk the lash being so loose that the push rod falls out of the cup. You need to find the push rod length that puts the lash within the lifters operating range. Also, in general less lash = less valve train noise, so once you find the range go with a rod that falls at the lower end, without going below its limits.

 

I'd go on The shorter side. Ls7 lifters tend to like less preload..060 seems to quiet them down.

 

No, I don't think there is room to turn the checker once it's installed. Turn it before you put it in....these are the best, simplest instructions for the 7702 Checker. I checked 4 of mine (2 on one bank, 2 on the other) and did the math in Excel, averaging the 4 intake and 4 exhaust numbers to determine my required length.

Comp Push Rod Checker Instructions

 

They are stock LS1 Lifters. The skirt on the botton doesnt fully enclose the roller.

 

Not exactly, the piston needs to be at TDC in the firing seqence. True TDC the intake valve is opening.

I followed Comps instuctions. Just tighten the rocker bolt. If the rocker tip can move up and down the PR is too short, if it doesnt move its too long. Youre looking for the zero lash (The lowest PR checker setting before you can hear the rocker click). Once you figure that out, you add the amount of preload to the length of the PR when you order. There are good instructions somewhere on here.

 

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you my wont to reread your post as in preload not lash and the more preload you have the more the rod sets in the cup not the other way round