valves rattling

[andrew ws6]

i have a 87 ss monte with a 350 30 over vortec heads and 500 lift roller cam and can not get the valves to adjust tried running and sitting still have a cheap set of roller tip rockers could that be the problem

[five7kid]

For whatever reason, roller tip rockers tend to be noisier than stamped steel. I don't know why, but that's what I've observed. I just adjust them as best I can and let it go at that.

[andrew ws6]

these rattle about the same all the way though untill it gets tight enough to bog out the engine

[five7kid]

If you adjust the lifters while the engine is running, it will typically stumble while turning beyond zero lash. Often takes several cycles (as in, several seconds of idling) for the lifter to adjust the plunger to the new spot. 1/2-1 turn down from zero lash (lifter plunger still at the top of the lifter, or when the really loud clatter stops) is the typical adjustment range (do them all the same, though). The factory setting is 1 full turn down.

I've been running 1/2 turn down for years because I heard over and over that you can avoid high-RPM float by doing that. The good-ol'-boy engine builder and fellow racer who put my heads together for me says he always adjusts them down 1 full turn from zero, and he revs higher than I do. The next time I adjust mine, I'm going to go ahead and turn them down one full turn.