Rhoads V-Pro Street lifters and push rod length procedure

[MattK2]

A set of Rhoads V-Pro Street lifters are going on a 455 with a Crane 041.  Adjustable Crowers also new.  I've read the procedure on how to setup the Rhoads lifters, but nothing about determining new push rod length.  It's odd that Rhoads assumes that your push rods are correct length and doesn't even bring it up on the published instructions on the website.  Not the best technical writing, but it's OK.

My guess:

Set the rocker nut down half the lift with the feeler gauge installed to account for the lash you'll use to reduce duration.  Install push road with the cup seated in the bottom of the lifter.  What else?  Or am I way off base?

[Kenth]

https://www.rhoadslifters.com/Pages/Installation.html

[MattK2]

Nowhere in those docs is a procedure on how to determine push rod length using mid lift theory. I could guess by looking at the way the lifter setup is supposed to be, but I’m not an engine builder.

[MattK2]

Rhoads answered my question.  Set adjustable rocker to desired position using mid lift method valve closed.   Install checker rod. Extend push rod so plunger bottoms out in lifter but doesn’t lift the valve. Add about 0.020”. Yeah he wrote “about”.  Do this before oiling lifters so they compress easy. That’s it.

[Cliff Ruggles]

That procedure is correct for all hydraulic lifters.

Mark the valve tip with a magic marker.

Bottom out the plunger.

Turn the engine thru and see where the patter is at.

You are looking for the NARROWEST pattern closest to CENTER.

Adjust your pushrod (adjustable variety) until you establish the best pattern.

Now SUBTRACT the amount of travel you plan on running from that number.  Most pushrods are sold in .050" increments, so plan accordingly. 

There are quite a few different lifters out there as far as plunger travel in concerned.  In most cases you can simply subtract .050" from your results and you'll be pretty close to where you need to be following traditional methods for adjusting hydraulic lifters. 

With Rhoads, some of them are set with a feeler gauge using specific values as we are seeing here.

It's still simple math either way, and a very important part of engine building.  Finding the best geometry using pushrod length provides the most transfer of motion to the valve and least side-loading at the same time.......