Adjust rockers to ..?

[kaj750]

I keep reading that I should check the adjustment of my rockers, when installed, but no mention of what I'm adjusting to.
I'm installing new lifters because I had one fail.
Once I put the rocker assembly back on, what specs am I looking to adjust? The lifters are hydraulic, so what's left?
My rockers do have a lock nut on top of a threaded portion that the push rod goes into.
I can't find any information on why these are adjustable nor how.
Thanks, in advance!

 

[Jerry Hall]

I was always told to adjust to 0 lash and then add 1 1/4 to 1 1/2 turn of preload.

 

[1 Wild R/T]

I was always told to adjust to 0 lash and then add 1 1/4 to 1 1/2 turn of preload.

That is a fairly safe range... It kinda depends on how you use the engine... street car, lots of normal driving adding a little extra preload will keeps things quieter... But if your hitting redline regularly we use to set 1/2-3/4 turn past zero lash so the lifters are less prone to pumping up & holding a valve open...

 

[Jerry Hall]

That is a fairly safe range... It kinda depends on how you use the engine... street car, lots of normal driving adding a little extra preload will keeps things quieter... But if your hitting redline regularly we use to set 1/2-3/4 turn past zero lash so the lifters are less prone to pumping up & holding a valve open...

My 451 stroker is at 1 turn currently and still has some lifter ticking on a few valves. I plan to give them all another 1/4 turn. I was easing in to it for a good cam break in.

 

[Jerry Hall]

My 451 stroker is at 1 turn currently and still has some lifter ticking on a few valves. I plan to give them all another 1/4 turn. I was easing in to it for a good cam break in.

I'm using the old Mopar performance iron ductile rockers and the adjustment is tedious.

 

[kaj750]

100% Street car. Rarely sees 5k RPM. Prefer quieter > higher RPM racey motor.

Thanks for the tips, guys. I will do this as soon as the new lifters are in and report back.

 

[Bird 426]

Bleed a tappet down, count turns from zero lash to bottom of the tappet, then back off half way.

 

[PurpleBeeper]

There’s an old Direct Connection valve lash adjustment chart & I follow that. Rotate 90 degrees, set one intake and one exhaust rocker valve lash and repeat. I run 1/2-full turn in after zero lash. So….following the DC chart, I loosen an adjustment nut way loose. I turn the ball/stud in/out with a screwdriver while I twirl the pushrod between my fingers of my left hand. You can “feel” right at the point where you get resistance to twirling the pushrod. That is “zero lash”. Now turn the adjuster screw in another 1/2-full turn & lock it down with the nut. 1 intake & 1 exhaust at a time on different cylinders per the chart. Readjust maybe ever other time you change spark plugs or every 20,000 miles or something (?)

 

[pnora]

Most cam and lifter companies recommend aprox .040 preload. Most adjuster screws are 3/8 fine thread. One turn is right about .040. So zero lash and one turn.

www.compcams.com
Section I. Setting pre-load with ADJUSTABLE ROCKER ARMS
Turn the engine in the normal direction of rotation. Start with cylinder number one (1). When the
exhaust valve begins to move, adjust the intake valve to the correct pre-load. To reach zero, take
the pushrod between your finger tips and move it up and down while you tighten the rocker arm.
Once you feel the pushrod has no more vertical slack, you are at zero pre-load. Make sure the
pushrod is in the lifter and the rocker arm seat when making valve adjustments. As stated before,
the recommended setting is .045" or 1 turn of the wrench past zero. Now, you can move on to the
exhaust valve on the same cylinder. Begin by rotating the engine over again until the intake valve
reaches maximum lift and is almost all the way back down. Then set exhaust valve using the same
method as the intake (.045" or 1 turn of the wrench past zero). Continue adjusting the valves on
each cylinder in this manner until all valves are adjusted

 

[kaj750]

Sounds simple enough.

I may have a bent pushrod (unless the end isn't machined correctly). Maybe my problem, seeing how the lifters look fine upon initial inspection.

 

[Geoff 2]

Most FT hyd lifters have about 0.150 -0.180" travel of the plunger when fully bled down. You can adjust anywhere within this range, it makes no difference to the actual operation of the lifter.
If you adjust so that the p'rod cup is just below the circlip, very little lifter pump up would be needed to pop the circlip out.....which would be caused by over revving or missed gear shift. So better to adjust the lifter with prod cup down 040-060" if your valvetrain allows for that adjustment.
Anti pump lifters use a very strong circlip, not the paper clip variety.