Adjusting Hydraulic Valve Lifter Lash

[Christopher R.]

[Duke W.]

Re: Adjusting Hydraulic Valve Lifter Lash

I doubt it. One-eighth to one-quarter turn is used as a "performance setting" and may allow a few hundred more revs before pump-up and quicker recovery after pump-up.

At this setting the valves should be quiet, but may require readjustment once or twice during the life of the engine to compensate for normal wear; 1/2-1 turn will usually compensate for any normal wear during the life of the engine.

what mfg./part number lifters were installed? What about the cam? Aftermarket cams with very aggressive flanks can be noisy.

Duke

[Michael H.]

Re: Adjusting Hydraulic Valve Lifter Lash

Adjusting hydraulic lifters to 1/4 turn down instead of the GM recommended one turn down setting has absolutely nothing to do with increasing the RPM potential of the engine or the RPM point where the lifters begin to pump up.
The only difference would be the amount that the lifters pump up. That's why many people set their hydraulic lifters at just slightly less than zero. When engine RPM enters the point of valve float, the "near zero" shallow adjustment only allows the lifter body to pump up slightly and won't cause a great power loss or possible valve to piston contact.