[1971455HO]

I realize most of you know this about pumped up lifters, I just want to be sure.

Can I adjust my rocker arms to zero lash, then set my preload to the recommended .025" - .035" (Morel Roller Lifter Recommendation for Iron Block / with Aluminum Heads)

With 7/16" studs...1 turn on the Polylok is .050". So I previously used 1/2 turn + 1/8 (5/8 total) giving me a RCH over .031" . My thinking is nothing has changed except a different roller rocker. I checked valve geometry...it's spot on using half lift method. Thinking it will just bleed off to where it needs to be, Right ?

Can I just set 'em and forget 'em ?

Thanks,
Eddie

[Schurkey]

Originally Posted by 1971455HO

Can I adjust my rocker arms to zero lash, then set my preload to the recommended .025" - .035" (Morel Roller Lifter Recommendation for Iron Block / with Aluminum Heads)

With 7/16" studs...1 turn on the Polylok is .050". So I previously used 1/2 turn + 1/8 (5/8 total) giving me a RCH over .031" .

That's .031 at the adjuster nut. Not .031 at the lifter plunger where it matters. You're not taking rocker ratio into account. The lifter plunger is being depressed more than .031.

Originally Posted by 1971455HO

Thinking it will just bleed off to where it needs to be, Right ?

Can I just set 'em and forget 'em ?

Yes, IF you turn the nut slowly so the lifter has some time to bleed-down.

[1971455HO]

Thank you so much Shurkey. That did not occur to me. All my life everybody said just turn it 3/4 turn and your done. You are Right sir.

I am now thinking, set up a dial caliper on top of the rocker at the ball socket above the pushrod and measure .030" preload while observing/documenting nut rotation as I tighten ?

Would you agree, after I know the precise amount of nut rotation to achieve .031" +/- 1-2 thousandths at the lifter I should be able to do the remaining rockers based on nut rotation?

[steve25]

Is your valley pan and Intake on the motor.

Has the motor been run before, or are the lifters empty?

[Schurkey]

I don't think it's anywhere near as critical as some folks have made it out to be.

How much lifter plunger travel do your lifters have? I've seen OEM lifters with more than a quarter-inch of plunger travel. I was sold aftermarket "upgrade" lifters that had .003 travel, and NO mention of the plunger travel being restricted on the lifter packaging. Therefore, I won't install lifters without checking plunger travel, and then pumping them up with ATF to verify the lifter can pass oil to the pushrod seat, and to verify leakdown rate.

If the lifters plungers are anywhere within their travel--not so close to the top that you wind up with lash depending on engine temperature; and not bottomed-out so that it holds the valve open--you should be good to go in terms of noise. MAYBE you'd have suboptimal rocker geometry due to pushrod-length issues, but that's a valve-guide wear issue, not a "noise" issue.

Some folks want the lifter plunger near the top of their travel, so they can't "pump up". Some folks want the lifter plunger near the bottom of their travel, so they can't "leak down". Others are just married to "one full turn" of the adjuster nut, or 1/2 turn, or 3/4 or whatever. This is the "Street" forum, so NONE OF THAT IS CRITICAL if everything else is set-up properly--adequate valve springs, proper-length pushrods, and so forth.

The big deal is accurately finding the zero lash point. Seems like 90%+ of all valve adjustment problems are rooted in failure to find the zero-lash point. And half of that is folks spinning the pushrod between their fingers as they tighten the adjuster nut, when they should be looking for up-and-down play instead. "Spinning" the pushrod often leads to the lifter plunger getting cranked to the very bottom of it's travel because both ends of the pushrod, and the mating surfaces on the lifter plunger and rocker arm are polished and lubricated. They "spin" very easily.

Find (true) zero-lash, add 1/2 turn, and don't obsess.

[Tim Corcoran]

Even for a street car 1/2 turn isn't the golden rule. Lifter companies recommend setting them at 1/2 the travel and they all have different amounts of travel. but some lifters make noise and you can try different settings that will quiet them down.

[1971455HO]

Thank you Shurkey....I can do all of that.
To answer steve25...Yes, the engine has ran and is fully assembled except the valve covers are off so I can adjust the valves after swapping rocker arms. I had a set of PRW roller rockers installed. I read here that they were not all that dependable. I don't want to have to go through this twice, so I bought a set of 1.5 Crower Enduro Stainless Steel rockers. Using Butler built Edelbrock Performer CNC 87cc Round Port Heads, Butler/Comp mild roller cam 224/230 .503./.510, 114 LS. w/Morel lifters. Morel recommended .025 -.035 preload.
The Morel Lifters have .120" plunger travel. They recommend 25-35 thousandths for my engine. I'm shooting for 31 -34 thousandths.

Based on Shurkey's last post on the matter, I'm gonna stick with what I'm doing and turn the polylok's a 5/8 turn that travels .031625". The push rod socket is only 1 inch inboard from the trunnion, I cant dream .031"at the trunnion is more than 1-2 thousandths further at the push rod.

Thanks very much gentlemen. I'm learning, that's a good thing.

[Schurkey]

Originally Posted by 1971455HO

I bought a set of 1.5 Crower Enduro Stainless Steel rockers...

...The Morel Lifters have .120" plunger travel...

...I'm gonna stick with what I'm doing and turn the polylok's a 5/8 turn that travels .031625". The push rod socket is only 1 inch inboard from the trunnion, I cant dream .031"at the trunnion is more than 1-2 thousandths further at the push rod.

.031625 X 1.5 = .0474

But with .120 plunger travel, it won't matter.

[steve25]

You shoukd also consider the fact that aluminum heads when fully up to temp will grow taller by .006" to .008" thus releaving some of your preload adjustment.

If you assume that you have perfect rocker arm geometry then any amount of preload will change that, the amount of preload you use will also reduce the lift you think you have according to the Cam spec's .

[1971455HO]

Thanks a lot to all of you guys. Great information. Your comments and experience is very appreciated. I'm now understanding how rocker ratio plays in to the adjustment procedure. And understanding expansion at operating temperature very much affects it as well. Butler recommends 1/2 - 5/8 turns from 0 lash. I get it now. When it's hot, it not as tight as it was cold.

I went back to Butler's website and looked up my lifters to see all the facts... here is what I found.

Product Description

Application: Pontiac V8 265 - 455
Diameter: .842"
Weight: 313g
Seat Height: 2.71"
Quantity: 16

Part Number: 5884

Pontiac Retro-Fit Hydraulic Roller Lifters require an aftermarket valley pan. Will hit most factory valley pans. See TPP-041S.

Preload (Valve Adjustment)-0 lash and ½-5/8 of a turn

thanks guys.

[Cliff R]

In a perfect World it does NOT matter how much pre-load you give a hydraulic lifter as long as it falls somewhere in the range of the plunger travel.

So in theory you could set them to zero lash, then give them 1/8 turn, 1/4 turn, 1/2 turn or ever a full turn and they will operate in the same fashion. This fact assumes that the oil trapped under the plungers is not compressible and that the plunger to lifter bore tolerances are spot on as well as the same or very close leak down rates.

However in the real World, especially today with lesser quality control and attention to detail I've found that it is necessary to run LESS plunger travel with hydraulic lifters. I started "tight lashing" them decades ago and have had ZERO issues following that plan.

Basically I set them with the plungers bottomed out instead of adjusting to zero lash then adding a specific amount of pre-load.

This can be done by putting a feeler gauge between the rocker and valve tip and run them down to zero lash, or just backing them up the same turns on each one. With less oil under the plungers you'll find that once fully warmed up any lifters with a higher leak down rate woln't be clacking away at idle speed. You'll also find that you woln't have any ticking hard on cold start-ups after the engine sits a few days, weeks months or years.

WAY back in the day the standard procedure was to just run them all down to zero lash with the engine running, then give them a half turn and forget about it. It worked pretty good when parts were better made and tolerances much closer. If you follow that plan today there will ALWAYS be a "ticker" in the bunch someplace, or a whole bunch of "tickers" depending on the quality of the lifters you are using.........Hope this helps some.......