The adjustment procedure for these lifters is DIFFERENT, you adjust the "clearance" with the plunger bottomed out in the lifter.
http://www.rhoadslifters.com/Pages/Installation.html "Adjustment is similar to solid lifters. Simply use a feeler gauge to adjust the exact amount of lift reduction you want, anywhere from .010" to .040", and that is exactly what you get at idle. Duration is reduced between 5 and 20 degrees at .050" lift depending on the adjustment."
This cam calls for .022/.024 lash. So you add that lash to the amount of desired lift reduction, and if setting COLD, use the proper lash correction. In my case, it's -.006 for aluminum heads. So, (.022 + .025 - .006) = .041 for INtake, .043 for EXhaust. On the base circle of the cam lobe for the valve you want to adjust, you place that feeler gauge between the valve stem tip and roller wheel of the rocker arm and tighten until the valve is just going to become unseated (with internal plunger of lifter bottomed out). Then lock this adjustment.
I still do not fully understand how this works, but I now have a better understanding of hydraulic lifter operation after solving the mystery
of why those JUNK IMPORT "100% Made in USA genuine Delphi / GM lifters" did not work. Jack Rhoads said that he would explain the VMAX operation to me - maybe it's time I gave him a call.
HOW TO INSTALL AND ADJUST RHOADS V-MAX LIFTERS
THE RHOADS V-MAX VARIABLE DURATION HYDRAULIC LIFTERS ARE ADJUSTED SIMILAR TO SOLID LIFTERS SO READ AND FOLLOW THE INSTRUCTIONS CAREFULLY
STEP 1
With intake manifold removed and camshaft installed, begin by inserting all lifters into engine block. It is best to keep the intake manifold off so that the lifters can be viewed while adjusting, but it is not necessary. The lifters can be properly adjusted with the intake manifold on as well.
STEP 2
Make sure the lifter being adjusted is on the low side (base circle) of the cam when adjusting, just like you would when adjusting any solid lifter cam. In this position, the valve would be in the fully closed position. For street use place a .020” feeler gauge, (use .030" for racing), or for aluminum blocks use a .010" feeler gauge (or .020" for racing) between the valve stem and rocker arm as if adjusting solid lifters, and tighten the lock nut until the lifter plunger bottoms out in the lifter shell and the valve begins to open. Now back off on the lock nut until the valve just closes and the pressure of the valve spring just begins to release on the feeler gauge. When you can just slide the feeler gauge back and forth with slight drag from the spring, the adjustment is correct. Repeat this process until all lifters are adjusted.
After the adjustment, the plunger position should be nearly all the way down to the bottom of the lifter shell, and not up against the retaining ring,
with no clearance in the valve train whatsoever. Please remember to adjust the lifter when the valve is in the closed position, or the adjustment will be wrong. For absolute accuracy, the adjustment can be repeated when the engine is at normal operating temperatures,
but the adjustment should be made with a .020" feeler gauge (.030" for race) for both cast iron and aluminum heads when the engine is hot. Also, never adjust the lifters at zero lash or looser so that the plunger is up against the retaining clip as standard anti-pump up lifters are adjusted. This will cause valve train damage.
OTHER SUGGESTIONS
You should never adjust the lifters with more than .030 to .035 thousandths of an inch, but you can use less such as .010”-.025”. When checking valve to piston clearances, tighten the lifters to .005” and conduct the test, then readjust them to the proper setting after the test is completed.
By tightening the exhaust valve more, you will get a lopier idle, which is preferred by some who like the sound. For higher compression engines, both the valves may be tightened to help reduce pinging. Also, tightening the adjustment will reduce the ticking sound at idle. This may be helpful with sensitive knock sensors that interpret the ticking as pinging. While this will not hinder the rpm potential of the Rhoads Lifter, the reduction in lift and duration at low speeds will be minimized with a tighter adjustment, yielding smaller increases is low-end torque, engine vacuum and producing a rougher idle.
As mentioned above, Rhoads Lifters sound similar to solid lifters at idle and low speeds. Usually this solid lifter sound is not heard until the engine warms up to near operating temperatures.
Grumpy, do you have any idea how these lifters work being adjusted with the plunger being at the bottom?