08VRZ06

Well I'm reinstalling the heads again, (had to pull off and send back to WCCH due to some bad exhaust valves, they didn't get the steel tip installed on the stem during manufacture) and decided to get an adjustable pushrod to just check my lifter preload. When WCCH had my heads the first time they did a stage 2 and milled them .030.

I checked #2 cylinder as it was the easiest to monitor while rotating the engine by hand. I put the exhaust on the base circle and was using a Comp 7702 pushrod checker which starts at 6.800 inches. It took aprox 18 1/2 turns out to get to zero lash on the rocker with the rocker trunion properly torqued. So at .050 per turn I came up with .925 plus 6.800 for a total length of 7.725 inches for a pushrod with zero lash. Then did the Intake and it was the same. So using the stock pushrod which are 7.800, I will have .075 preload on the lifter, which I understand is about ideal......

Does this sound correct to you guys?? I would have thought that with the .030 taken off the heads with stock pushrods my preload would have been around .110.

I have a Katech 110 cam with the CHE rocker mod with factory lifters...

Thanks......

Mark

Michael_D

I like to use a dial more than screw with those adj rods. Takes a bit of work setting up a metal plate for a mag base, or finding metric bolts for the threaded dial rods, but worth the effort. The LS7 lifter is pretty forgiving. A lot of folks run a lot of different pre-loads. Kind of like women and their shoes I guess. I just find an average of total lifter plunger travel for any hyd lifter (measuring about half of them with the dial), then order pushrods that will set the pre-load at mid travel point. This method will give you a nice cushion for thermal growth. When I measured my LS7 lifters, I was seeing an average of .200 plunger travel. Pre-load varied between .90 - .110, so I left them be.

08VRZ06

Well checked #1 cylinder last night and have the same results. So I should have a lifter preload of .070 - .075. I also took a pushrod and laided it across the tops of the valves and with the lash caps on the intake valves and the pushrod laided over to exhaust valves I can put a .006 feeler gauge between the pushrod and the top of the lash cap in the intake valve, so all of the stems are about the same height.

Mark

Sébast19X

Way to go !!!
You have the correct preload