pcsmits1

I have a stock ls1 with stock lifters 7.400 comp pushrods and a ls1 hot cam the gmpp one I was reading an old post about adjusting from zero lash where it had posted a procedure stating it should be 1 1/4-1 3/4 turns to get to 22# I get 2 1/4 turns past zero but at about 3/4 of a turn past 0 they start to open the valves I have tried the stock rockers and the summit full rollers both do the same thing any ideas what might be happening heads are 241s decked .020 and new ls6 valve springs with a 3 angle any help is greatly appreciated

PREDATOR-Z

Measure for p-rod size. sounds that your p-rods are too long.

pcsmits1

going to do that tomorrow hoping they didn't sink the valves to far into the seats I was thinking a .020 shim would fix it but it doesn't

pcsmits1

ok I need some help I am using an adjustable pushrod and when I get to zero lash and turn it more then 1/2 turn the valve start to open I have the engine on the stand using a flash light into the spark plug hole I can see light all around the valve. could it be the lifters are pumped up and need to be pushed down over night to bleed the oil out?

td1168

iTrader: (2)

How are you determining 0 lash? If your valves are opening 1/2 turn past 0 lash you're not doing something right. I don't care what length pushrods you are using 1/2 to 3/4 turn past 0 lash shouldn't open the valves. Are all of your valves doing this? One turn past zero lash gives you .050" preload . You should be going about 1 1/4 turns past 0 lash to 22 ft/lbs.

pcsmits1

putting the lifter to the base circle of the cam rocker at the point at which the slack is just gone. I did adjust the pushrod checker to where 2/3 of a turn past zero to get 22# I then turned the motor over left it with the valve all the way open for about an hour turned it back to the base circle of the cam removed rocker let it sit about an hour reinstalled the rocker the same and i didn't see the valve open or light around it do you think the lifter was to pumped up? the motor only has about 30k on it and been sitting in my garage for about 6 years.
I have used pedestal mount rockers alot over the years on the 5.o ford and delt with shimming them to make stuff work just found it odd the valves are opening and it was on 6 diff spots doing the same thing

pcsmits1

if any one ever runs across this searching for the same issues try the opening the valves and let it sit to bleed the lifter out then try to check again if they have sat along time some times they get stuck and the plunger doesn't want to compress. td1168 helped me a lot in pm's hes a great guy with lots on information and very reasuring

chrisfrost

iTrader: (8)

I've had similar issues with lifters that were sitting without running for a while . I swapped a motor and it would'nt start so i checked the valve adjustment and They were held open just a few thous so I pushed the valves closed by pushing on the rockers and kept turning it over and eventually it started and ran rough but smoothed out over maybe 10 minutes running . I figure there must have b een too much oil in the lifters.