Hydraulic lifter, roller cam valve clearance/preload

[bobcowan]

Hydraulic lifters are designed to run some pre-load. If you're not sure if you have any or not, you should probably take the time to do a proper adjustment to be sure. It's not a difficult task, and doesn't take long.

One trick though. Over the years, it has been generally accepted that you tighten the adjuster nut down until you can't spin the push rods with your fingers. But with modern materials and lubes, you can often spin the rods after they're adjusted properly, so that doesn't work any more.

To find very lash, tighten the nut down with your fingers until you can't turn it any more. That's zero lash.

Here's some complete instructions: http://www.compcams.com/Technical/In.../Files/250.pdf

[blykins]

It all depends on the lifters.

Comp has two sets of lifters, one set requires hardly any preload at all, the other requires zero lash plus a 1/2 turn.

If you're running it this way, I don't see anything wrong with it.

[CowtownCobra]

Originally Posted by bobcowan

tighten the nut down with your fingers until you can't turn it any more. That's zero lash.

Been doing that for years and many thousands of miles on several moders. Works fine.

[DAVID GAGNARD]

I took an old valve cover years ago and cut a strip out of the top about 2 inches wide, the length of the cover...
this is what I do, start the motor, get it to full operating temp and then shut it down, remove one cover and put on the "modified" cover on (this lets you do the adjustment while the engine is running and not have hot oil leaking all over everything), one at a time I loosen the adjusting nut slowly till I hear the valve "ticking", then tighten slowly till it stops and then go from 1/4 turn to 1/2 turn, repeat on all valves and then go to the other side of the motor........been doing it this way forever (almost) and have never had a problem with my valve train..........

David