Harland Sharp adjustable roller rockers / lifter preload

[Strokermjcomanche]

So I’m putting together an engine. Got a few things to finish up, One is getting the lifter preload set. I’ve done this before on my GM 2.8, With it running backing off the center not and then tightening Till the noise goes awayEtc . 
 

The problem I’m running into here, or at least I think I am is if I lift the rocker arm off of the valve I can stick my pinky up underneath there. I can say I honestly haven’t checked that in the past to know if that’s good or bad. If that is acceptable how should I set the lifter preload/ Or what should It be set  to? Harland Sharpe’s website was vague in my opinion. I got these used so they came with no instructions.

 

I would also like to add that the block was never decked because it was within spec, it is a new Edelbrock head , I am using factory length pushrods , And 1.6 ratio roller rockers , The Cam is comp cams 496 lift ,cometic  gasket 

[Strokermjcomanche]

[Gojira94]

You shouldn't be able to lift the roller tip off the valve stem, obviously. If you run out of threads for the poly locks before you get to the trunnion on the rocker, you've got the wrong studs. As for preload, it very much helps to know the plunger travel distance spec on the hydraulic lifter. Say if it's got .060" of travel, and you're running 3/8 x24 studs you'll want to go 3/4 to 1 turn past zero lash to get between .031" - .042" into the lifter's travel range (about the middle of it). Pushrods could also be too short if I'm understanding what you're saying...

[ghetdjc320]

I used the same method as above once confirming the correct pushrod length. Set to zero lash then go a bit further (in my case that was one full turn)

[Gojira94]

Ideal rocker geometry has the rocker at a 90* angle to the stud at the mid point of cam lobe lift. This keeps the roller tip well centered on the valve stem and prevents any sideloading on the valve stem that might otherwise occur. Very few cams have such a difference between intake valve lift and exhaust valve lift as to make it ideal to have different pushrod lengths for each ( > .025" lift split ). Use an adjustable pushrod length checker of appropriate size range. With a magnetic dial indicator on the tip of the rocker directly above the roller tip/ valve stem, roll the engine over slowly. As you come off the base circle of the cam, the nose of the rocker will drop. Keep rolling the engine slowly until you reach max lobe lift  and divide that by 2. Roll the engine over again until that valve is closed and again begins to open. when you reach the /2 number you got from max lift, STOP. Adjust your pushrod length checker until the rocker and stud are 90* from each other at zero lash. Imaginary line through the center of the trunnion and roller tip is one line, center line of the stud is the other. If your preload, based on the plunger travel exceeds .025" add that to the pushrod length you get from the pushrod length checker.

 

Simple low tech pushrod length approach without a dial indicator: use gear marking compound on the valve tip and lengthen/ shorten the pushrod length checker, rolling the engine over, repeating until you have a narrow sweep pattern centered on the valve tip.

[Strokermjcomanche]

The lifters I used were Mopar p4529220 / pushrods are p4529675 . 
 

With the current pushrods I have, while turning the crank it stays near the center of the valve stem. Although If I have the incorrect pushrod length that will have a factor correct? I have an adjustable pushrod coming. 
 

I guess another question would be if I’m only supposed to partially preload the lifter What keeps me from being able to grab the roller part the rocker arm and lift up on it ? 

 

 

[75sv1]

I'm wondering two things, Solid Lifter vs Hydraulic lifter as for adjustment? Also, hydraulic lifter pumped up with oil?  When I did my 351W back in the late 80's, I used feeler gages to set the adjustment on dry hydraulic lifters.  I remember 0.042. I do have to check this on some fixed or non-adjustable Harland Sharps. Just curious, Stroker? Newcomer? The thermostat housing I take as a Newcomer. ??? Intake 91-99 vs a 99-up? Newcomer seems to like the rectangular one. 

[Strokermjcomanche]

I have already primed the engine, Plus the lifters were soaked in oil previously before installed.

 

4.7 stroker . 96 intake . Gibson header

 

newcomer t stat housing and lifetime copper intake/exhaust gasket along with the winged washers and bolts for intake exhaust .

[75sv1]

I had to do a web search and take in what they were saying. Its been since the late 80's since I adjusted a set of Roller Rockers. Well, actually sine 2004 or so. But I haven't run that engine. As I remember I adjusted the Rocker arm down till the push rod had no up and down slop, or the pushrod had some tension on it so turning had a bit of pressure. Then 1/2 turn more. I think that is possible with the lifters pumped up. Mine would leak down , if the valves were lifted and had some time. Then I checked with a feeler gage and checked against what specs were for the stock lifters. 

[Gojira94]

Yes, hydraulic lifters (flat tappet and roller tappet) will leak down. That's normal, since you're literally squeezing the oil out going past zero lash. When the engine's running, oil pressure through the lifter gallery will keep them pumped up and immediately take up the resulting slack. Hit zero lash, add preload, done. Solid roller or mechanical flat tappet require hot lash with a feeler gauge, as accurately stated above. Totally different animal.

 

I cautioned against too light a preload, which is especially consequential for hydraulic roller lifters. In the GM world, the "LS7" lifter has been popular and misunderstood. A fair number of guys were just blindly going 3/4 turn past zero lash. On a 7/16" x 20 stud, that's .050" which is fine, as that lifter wants to be somewhere between .045" and .080." On a 38/" x24 stud, that's .031" and the lifter rollers would skate and destroy the cam lobes and lifter rollers, scattering hardened metal throughout the engine.

 

That being said... the lifter you listed above has no generally known specs for plunger travel distance. Short of measuring the lifter plunger travel on the p4529220, go with the FSM valve adjustment instruction. That should get you safely into the lower-middle range of its travel/ cushion. Pushrod length is important to at least get pretty close for valve stem longevity, and pushrods generally aren't that expensive. Very nice build you've got there!