A pushrod a bit longer would be trapped even at full lifter colapse and still allow proper adjuster hieght? What are the consequences of increasing preload that way to eliminate most of the travel from bleed down? ?

That is the way mine is set up now. I am .020 off the bottom with Morel Hydro;s my pushrods are Ball,ball

Your post kinda answers my question. Obviously your car is running well? What cam and rpm?

Are you guys suggesting to run multiple turns of preload? That has always made the car run horribly, and occasionally bend valves. My vote is for crappy parts. I have a Comp set of lifters in my truck that there are two lifters that will clack like a machine gun here and there, One day its fine, 3 days later will clack, 2 days later will go away for a while then come back a couple of days later. The clacking begins an ends on start-up. I have isolated them dis assembled them and nothing there, just in my opinion a poor valving design, a plate instead of a steel ball. Been like this since 2003.

It is a street strip car, with the long runners I shift @ 6200, the car runs ok, I run 1.6 T&D rockers, sorting out a fuel delivery problem at the moment.

Agree with this, .080-.090 has always ran bad for me when engine is cold, always set them .020-.030 from the clip. Maybe it is thick oil, high oil pressure that can't bled down. How about a spacer for the plunger to limit the travel? I know stock motors never seem to be an issue, aftermarket cams, lifters and heavy valve springs do. You would also need to be sure that the piston to valve clearance is more, and valve spring coil bind is not an issue if you want to run them .090 in the lifter, or bigger problems are going to show up.

In my experience if it runs bad then the lifter is bottomed out & holding the valve open. use a .020 feeler gauge & go from the bottom of the piston travel. I will also say this, the ONLY reason I went hydro roller is this is a street car, many have said solids will not live on the street long term. I have my theory on why, I will not EVER use Morel lifters again.

How can more preload change the way the engine runs? It can’t. It will only change if the lifter Is bottomed out. Oil viscosity has nothing to do with it. This issue is a case of the lifter bleeding down when stationary load is applied. If the lifter is functioning properly, this doesn’t happen. Obviously there are issues with some lifters. When the lifter fails to hold oil it bleeds and increases lash. The extra preload is a bandaid to keep the pushrod in the cup. Nothing more, nothing less. If it works in your situation it could be a good alternative to swapping parts.
Doug

This was happening to my 505 stroker. I was using a Comp Cams hydraulic set up. Was very frustrating and usually at start up. Nothing worse than having to pull a valve cover in parking lot to get the pushrod back in. My engine builder finally fixed it. I'd have to call to see what specifically he did if you still need help with it. I believe he used a good amount of pre load and some different springs/retaining clips. Have not had an issue since he did that. I've known a few people with 440's locally that have had issues with similar set ups.

If you read up on this issue there are or were hydraulic lifters with .060 travel, I do not know where to buy them, and lifters with .215 travel johnson is one brand. If I had .060 travel it would be no issue. Thick oil will cause problems, the experts say the lifter can only bleed down from the clearance between the plunger and the lifter body. If you Google lifter preload, everybody most recommend .020-.060, because hydraulics will pump up and cause pistons and valves to hit, and cause valves to hang open cold, so they run bad. If I could buy lifters with that .060 travel it would solve all my problems, or I will just buy a solid cam.

The only way a hydro lifter will pump up is if the springs are to weak, ie valve float, valve train instability at RPM, & at rpm with good spring they bleed down not pump up

The last set I replaced(sbc with comps) I contemplated opening up the lifters and adding shims. Then, I thought, why bother.

An important thing to keep in mind is....... not all the lifters are designed to be run with the same amount of preload.
And some of the pricier, higher end, high rpm units call for very specific preload settings....... and many people successfully run that type of lifter with the adjustment made by setting them “from the bottom”.
That’s probably not going to be a good practice(running them nearly bottomed out) for many of the “lesser” lifters that aren’t designed for “extreme duty”.
For example, in their FAQ section, Gaterman specifically says not to run them bottomed out.

The bottom line is, if your combination of parts is assembled in a manor where the plunger in the lifter, after preload, can travel farther than the depth of the pushrod cup at the rocker arm, then there is a possibility for a certain situation to occur after engine shut down, that can result in the pushrod falling out on the next start up.

My personal opinion on it is, I can’t see any reason why any retrofit hyd roller lifter sold by a performance cam company would need more than .060” total plunger travel.
This problem just wouldn’t be happening if the lifters were made that way.

Kinda my point with .060 lifter, even .090, it is not just the mopar guys with issues, seems to be widespread if the combo is just right.

If you dig around enough, there are plenty of stories.......like this one, using some expensive lifters(well...... trying to use them):

https://www.speed-talk.com/forum/viewtopic.php?t=36843

I’m still of the mindset.......”just give me a solid”

Particularly if the HR option is a “retrofit” scenario.

go take an good running engine with a 1/2, to 3/4 turn preload and put 2-3 turns on all the rockers and tell me how that works out for you.

I thought the oil pressure to the hydraulic lifter only took out valve lash, when the lash is
then zero, oil pressure will not compress the valve spring. Then when the cam lobe pushes
against the lifter to open the valve, there is a little bleeddown, but this happens so quickly
that the lifter is ALMOST hydrolocked. The lifter is not bottomed out at this point. And then the valve is pushed open.

Unless I misunderstand something.

If you tighten them down 2-3 turns it seems like the cups would be bottomed out?

The 3/8x24 threads per inch adjusters move the tip in or out .041666, which I round up to .042, per one full turn of the adjusters so doing the math on the lifter side of the rocker arms make the lifter plunger see the same amount of change, correct 1 divided by 24 =.041666
If your using 7/16 x 20 adjusters each full turn equals .050 looser or tighter per each full turn of the adjuster.
I use between 1/4 to 1/2 turn preload on both the 3/8 and 7/16 adjusters, maybe a tiny bit more on aluminum heads, 1/3 to 1/2 turn on 3/8 and 2/3 to 3/4 turn on the 7/16 adjusters at room temps and then reset them warmed up
I am not a big fan of any of the after market .903 or .904 hydraulic roller lifters that I have used yet
Hopefully soon, in the near future
In the meantime I'll stick with a good set of solid roller lifters

To honestly see what works, and doesn’t work, follow the boat engines. Hyd rollers are used extensively in marine applications, and if you want to break something, that’s where it will happen, in a boat. Only circle track dirt racing breaks more parts....lol. The boat guys have narrowed it down to only a couple brands that will survive. Mopars are even worse than a BBC, because of lifter weight.