Valve Adjustment with Chromoly Push Rods, Krusty's method Options

[malcolm2]

Prior to changing anything, I used Krusty's method and got my thinnest gauge. I found a 0.002....

I had rotated the engine around and checked my

1. Swivel Foot on each valve. They spin.
2. I also checked for any rocker movement... or really I kept rotating until i got a CLICK when i wiggled the rocker and spun the Swivel.

So at that point i was able to get the 0.002 gauge in. Remember, I am SHOOTING FOR ZERO LASH HERE

Should I try make that small adjustment so the 0.002 gauge won't go in?

KRUSTY'S Valve adjust method

[GregAmy]

My technique is the Krusty method, then slowly tightening the adjuster while moving the rockers up and down, to zero movement. Then I back it off like 1/16 a screw turn (just a touch) and tighten cause I figure when I tighten the nut it might follow it a little bit (despite a screwdriver to hold it in place).

It would be nice to know, theoretically, how much length those pushrods lose so I can have an idea if, for example, 5-thou too tight would be compensated.

But in the end, with a lift, a remote starter switch, and the Krusty method, it's not a time-consuming process at all so I do it regularly, like at each oil change.

Miss ya, Cap'n.

[malcolm2]

So you have never followed up with a gauge? You think 0.002 should be reduced?

I saw the note how the final tightening can reduce the last measured setting.

[GregAmy]

So you have never followed up with a gauge?

I mean, it's "zero lash" right? How does one measure "zero"?

The implication of the stock parts (stainless steel pushrods?) is that the valve lash from cold reduces as the engine gets hotter; the system, primarily the pushrods, cylinder length, head height, reduce the valve lashlooseness as the system gets hotter. So the reason you sets the cold valve lash at a certain positive (loose) value is so the valve (primarily, the exhaust valves) don't go zero or negative "looseness" when everything warms up (a slightly held-open exhaust valve will quickly start to erode and burn up the edges/lips of the valve).

The implication of chromoly claim of "zero lash" pushrods is that as the engine warms up the total lash/looseness increases so that as long as you set it at zero or slightly more then the valves (again, primarily the exhaust) won't be partially open when fully warmed up. Of course the remaining stock system (rockers, valve shafts, etc) are the same but the pushrods are not increasing in length as much as the stock ones so "zero lash" is sufficient.

This is why modern hydraulic lifters are preferred, since they will, theoretically, compensate for these changes in block, cylinder, head, rocker expansion from cold to hot. Set and forget...no more regular valve adjustments.

[Ishley]

I set mine up to what is called loose zero. I Tighten until I can feel it just come down on the pushrod but I can still spin it with my fingers. After I lock the nut down, I check if it still spins and I try to move the rocker to see if I can hear it click/clack. Sometimes it takes several attempts If I don’t hear anything and I can still spin the rod with my fingers I know I’m there.

Works for me.