It will run rough because the valve won’t shut. If you don’t bottom the lifter all the way it will bleed the excess oil and return to normal.
Doug

2-3 turns doesn't bottom any lifter I have come across. A brand new Comp hydro roller takes over 5.

the seat or cup will not stay stationary, the effective height changes all the time. The more pre-load you run the lower the rpm you'll float (lifter pump up} the engine. The more pre-load you run effects the vacuum at idle, and quality of the idle. I'm not talking about enough pre-load to collapse the lifter either. The less pre-load the higher the rpm potential. A race hydraulic lifter will have a robust snap ring and suggest little to no pre-load. A half turn ether way setting valves always has a noticeable effect on the engine. Let alone 2-3.

Back to the original post unless you have less than a quarter turn of pre-load that shouldn't have caused the issue. I will say though a 1/4 turn of pre-load typically that will be noisy (they run good there though). My guess would be a collapsed (bled down) lifter at startup stuck for a second. How much pre-load are you using? What brand lifter?

I edited these statements. Maybe I have something to learn. But I see no concrete basis for the statements listed above.
Doug

Funny how I have a Comp in my hand right now and it has .198 of travel. Magazine articles are gospel huh?

I’m not really sure what you’re implying, but there are parts of those 3 articles that discuss the pros and cons of running a little....... or a lot......of preload.

Also, I can’t tell by the pic...... is that a hyd roller lifter?

Yes, Comp hydro roller. In the one article you have someone saying that stock lifters have .120 travel and a suggestion that cheap lifters have had upwards .180 well ,wrong A $400+ set of Comps has .198. I trust in my experience/knowledge (and a few old timer friends that have been there ,done that a thousand times, Thanks guys!) and believe very little what I read on the internet sadly because of all the b.s. you get mainly for marketing purposes. I'd rather hear it from experience than a Hot Rod article

You’re in luck.
I guess you skipped right past csk’s post where he said:



Running them like that is more common than you think.

Nonetheless, I’m a firm believer in doing what works for you....... so if you don’t have any luck running that way...... stick with what you’re having success with.

So just so I can understand in the case of the comps , there are those who are running/suggesting to run them, with 4 and 1/2 turns after 0 lash?

Stock magnum lifters have .200 or more, stock ls lifters are .215, looks like the 3rd gen hemi are that way too, so like you I have never seen a stock hydraulic roller lifter that has .120 or less. I would sure buy a set, .060 would be even better. I would like to know what kind of seat pressure, and wt oil these guys are running that can run the lifter near bottomed out, and never have piston to valve issues. I am betting it is not 130 like most cam companies recommend so the cam does not go flat, or they have .250 piston to valve clearance. If I turned mine down 4-5 turns I bet it would not start with 125 on the seat, disregarding the pistons hitting the valves, at least with cold oil.

Yes curious about this set up also. A younger me ran the valves down too far (nowhere near 4-5 turns either) on a small block Chevy and bent a bunch of valves.

Hydraulic lifters. Either plagued with pump up, or bleed down. Different problems, different solutions. Questions is there a place in the middle where they work. Maybe?

Charlie's hydraulic from Hughes specs a 220 lbs seat and 550 lbs over the nose pressure. Same as my solid roller. I would view the 0.020" off the bottom more like a lash verses a preload, IMO.

I’m pretty sure he’s running beehive springs with a fair amount less load than that.

I also believe his lifters have .120” plunger travel.

Sorry about that Russ, I had forgotten about the wrong spring specs until you mentioned it,, the cam card is wrong that came with my cam,,, on the web site for my Hydro cam it says 155 seat 415 open, when I got the cam I had to call & sort out what springs are correct & they said it was a missprint for the 220 seat springs, as Dwayne said I have Beehives, also I totally agree on my .020 from the bottom is really just a lash setting. here is the cam card from the website The lifters are .120 travel, I got longer pushrods so I could set them from the bottom of travel & keep the amount of threads on the adjusters correct,, Needless to say but, the only way a pushrod can fall out on my junker is if something REALLY breaks & fails, not just a collapsed hydro lifter

Let's assume the lifter preload is some where between .xxx preload and not bottomed out. Let's also assume the lifter doesnt bleed down and the valve train doesnt go into false motion. In this case the amount of preload means absolutely nothing. Now if it bleeds extra preload may keep the valve train clearances close enough so the valve drain doesn't gain enough lash to fall apart. If the valve train is unstable to some degree minimal preload will limit the amount of positive lash in the valve train. If you have both issues you have a problem. Other than this there is no magic. As usual it's a case of over thinking.. My 2 cents
Doug

I agree with you. not arguing with you, my setup is proof of your statement

Too many assumptions, real world/valve-trains ain't perfect, My 2 cents Have you ever over-reved (floated)a hydraulic engine, I've done it many times. Minimizing pre-load helps this.

CSK to be clear, you set you valves by putting them on the base circle, turning the adjuster until the lifter is fully collapsed, then back off a 1/2 turn? My next question is have you ever set you valves after the engine was run/primed? I would think that the one time, you could get to the bottom of travel was with a clean empty lifter. After priming any inconsistent residual oil would put them all over the place. Sometimes they won't move at all (or anytime in the near future). What then?

DVW funny you said that..... I was thinking you guys are overthinking this. O lash, 1/4 to 3/4 turn and move on.

I want to say good luck to the original post trying to get all the lifters completely bled down, to do the bottom of travel method If you go that route.

Yes & it is not hard to do, they will bleed down, you just have to be patient , I use a feeler gauge, after waiting you can move the feeler gauge until it bottoms out THEN you know it is bottomed when the feeler is tight, it does take some practice, been doing it this way for a long time on other applications.

Had a bit more time to further tear things down. Popped the intake off and pulled the problem lifter set out. Can't see anything out of the ordinary with it externally, but I don't have a set of snap ring pliers to take the lifter apart. I lost the original lash measurements, so I measured the adjuster in relation to the rocker to get an idea the variation between all of them. Came out with these numbers:

8E: .711"
8I: .696" <----Problem lifter
6I: .718"
6E: .698"
4E: .731"
4I: .697"
2I: .705"
2E: .702"

Are variations in lash like this acceptable? The problem hole is the lowest, but only by .001" from two other lifters that have never done this. I'm going to assume I should put it back together and get proper measurements before deciding what to next. I liked the idea of converting over to solid, but I just don't have $1k to drop on lifters right now.


I didn't put this motor together either. So far I've been into it for a blown head gasket, worn bronze cam gear and this.

Imo, what you’re measuring on the adjuster is meaningless.
Different valve tip heights, and camshaft base circle diameter will impact where the adjusters are.

Just curious.......How sure are you those are Comp lifters?

I haven’t seen any Comp HR lifters for a BB Mopar in quite a while, but I don’t recall them having the skirted wheel.
Of course..... they may have made revisions or changed vendors over the years.
( Edit - I looked through some pics on line. It appears they have had shrouded/skirted wheels for quite a while..... see pic, BB and SB )

Nonetheless........ if you adjust them like I suggested in my first post, I think you’ll find the problem goes away.

Yes, that may require different length pushrods.

Btw, what I see....... looking at your measurements is...... the “left” rockers have the long measurement, and the “right” have the short measurement.

Though....One thing you could check now is...... how far from being bottomed out does your current preload put the plunger?
What you have for total plunger travel would also be interesting to know.