454 lash adjustment

[Mike1973]

1984 GMC 3/4 ton 2WD 454

Does it make a difference if lash is set on a cold, static motor as opposed to a motor that has been warmed up and lifers pumped up?

I have new lifters, set the lash cold with the lifters never pumped up (empty so to speak.)  Basically did the whole thing of get the lifter on the heel turn down until zero lash then an additional 1/8" turn.  I have sense run the motor and there isn't any noise I'm just wonder if indeed setting lash with "empty" lifters is correct or when they become pumped up after running they end up to tight and keep the valves open a bit.

Thank you.

[bd]

One-eighth turn on OE lifters is a little shallow for the factory valvetrain.   But, no "clickity-click" means you did good!  If the valves become noisy, readjust for 1/2 turn down from zero lash; GM specifies 3/4 turn.

With a factory grind, hydraulic lifters won't 'pump up' and hold a valve open unless the engine over revs and floats a valve, a valve spring breaks, or the lifter is adjusted to preload the valve (hold it off its seat) by bottoming out the lifter's internal piston, effectively making it a solid lifter.

[Engineer]

On a stock cam valvetrain geometry isn't that critical. However, GM specifies 3/4-1 turn after the lash is zeroed. You should consider tightening to GM's spec so that your rocker arms are are more squared to the valve stem, and push rod.

The closer to square your rocker arms are with the valve stem at mid lift, the less the rocker arm will scrub across the valve tip.