nunus79

I went to Speed-Pro's website & copied this info about anti pump-up lifters:

Hi-Rev Hydraulic Lifters
Speed-Pro Hi-Rev (commonly called anti-pump-up) hydraulic lifters feature the same quality material and construction as the conventional hydraulic lifter. A special high strength, steel retainer is used in place of the normal spring clip to precisely limit the travel of the plunger during operation. With plunger travel limited, adjustable rocker arms must be used to effect a lash adjustment of .000/.002". This then allows the valve train to perform more like a mechanical system, thus allowing high RPM operation. Because of the high RPM capability and the elimination of frequent lash adjustments (which are required with mechanical lifters), Hi-Rev hydraulic lifters are the best choice for all-around performance engines. Hi-Rev hydraulic lifters can be identified by the prefix ““HT”” and the suffix ““R.””

Lash Adjustment Directions for Hi-Rev Hydraulic Lifters

These racing hydraulic lifters are designed to eliminate so-called lifter ““pump-up”” at high RPM In order for the lifters to perform this function the valve lash is critical and must be performed as follows:
. The preliminary lash adjustment on engine buildup requires the lifter to be on the base circle of the camshaft (valve closed position) and then to just remove all rocker arm to push rod clearance. This can be determined by rotating and/or moving the push rod while tightening the adjusting nut. When resistance to turning or movement is felt, the lash is satisfactory for engine start-up.
. After the engine is running and has been warmed up, the final lash adjustment can be made, preferably at hot idle. Set the valve lash at .002". If obvious valve click is heard at this setting, tighten down adjusting nut until click just disappears.

From the Hughes Engines webpage:

Any tappet adjusted to .000" preload will operate as an "anti-pump up" lifter. However, when using a lifter with a small wire retaining ring such as OEM lifter (shown as #5001), there is a higher probability of the retainer ring failing with this amount of pre-load. Anytime maximum RPM is necessary and a minimum tappet preload or lash is used, racing lifters with heavy duty retaining rings (#5003) are required.

Just thought I'd share this info as some of you had some interesting questions regarding valve lash adjustments. Hope this helps!

Matt Gruber

thanks for posting their advertisement.
if they were really anti-pump-up they would be set normally, and not pump-up at higher rpm.
Obviously they still pump up, but the stronger retainer is less likely to fail. But it does say for racing, and i do agree it is something to try at the drags.
Pretty comical that they suggest 000/.002 will not need adjustments! Like this product eliminates rocker arm/pushrod/cam/valve tip wear! :rolleyes: But, again, at the drag strip it should be OK.
i will never buy H lifters again. They need too many adjustments :rolleyes: :lol:


[Modified by drives61, 3:04 PM 7/3/2002]

Fevre

Very interesting stuff. But this raises a few questions with me: (not intended at you Nunus79):

If you set the preload at .000 or even .002 why not just go with a mech lifter? I thought the whole idea behind the hyd lifter was that the lifter keeps filling with oil as the valvetrain wears so you don't have to adjust them once they are set. Also if you do set it at .000 won't you have to reset them just like a mech lifter once you hear ticking from valve train wear? Granted there isn't much wear and it may take a while before it happens but it will happen and you will have to re-adjust them.

Guess I don't see the benefit of them over either a standard hyd lifter or a mech lifter UNLESS you drive it as a street machine most of the time and race it once in a while. Then you could use the normal preload (1/4 turn to full turn) for street driving but adjust to be more like the mech lifters when you do race it. Of course you might as well go mech if you are going through that trouble.

Fevre

You have quick fingers my friend. :lol:

if you can't tell.

nunus79

One of the important points that I hoped this info brought out, although not directly mentioned, is that there is a reduced amount of "crank-down" room on anti pump-ups because of the heavier retaining ring. Cranking down too far will collapse the lifter and if left too tight, will bend pushrods or bust the lifter, etc.

I believe Tom454 wrote up a real good post once about lifters & lifter adjustments. What I remembered from it was that true "zero lash" is not when the lifter tick is gone. When the tick is gone you've probably past true zero. Made sense to me. Anyway, that leads me to believe that when the tick is gone, you are into the "plunger action zone". This plunger action zone is smaller on anti pump-ups vs. conventional lifters. A full crank down on an anti pump-up + the initial lash adjustment MAY be enough to collapse the lifter.

I saw bent pushrods & busted anti pump-up lifters before.....the only reason for them being broken was too much preload (crank down).

Fevre

I guess one other good thing about them is that it gets rid of the lifter noise if that bothers you.

Matt Gruber

nunus79
good point about the crank down distance.
Don't these cost like $5 each?
Anybody actually use them?

Anybody eles that thinks 0+1/4 will give solid lifter performance is dreaming. i know lars uses 0+ 1/2, what purpose can that serve?. it sure won't extend the useable rpm range.

Whatever happened to mushroom base solids? They were said to allow roller type grinds on a flat tappet. BS i guess?

nunus79

Fevre
I don't know the reasons or pros and cons of the anti pump-ups. But for me, when I was looking around for a cam, the solid grinds were just too aggressive for my particular setup, moderate compression & gearing. The hydraulic grinds provided a way better selection to pick from. Anti pump-ups helps remove one of the concerns about running hydraulic lifters at higher rpms. I think most gearheads don't mind checking/adjusting their valvetrain periodically. So, using/maintaining anti pump-ups is not a problem for them. :cheers:

gdh

Will let you know how mine sound and perform on Friday.

Matt Gruber

Well, solid lifters, with no moving parts do cost more than regular H's. set of 16 $45 vs. $32
And there are less cams to choose from. But, the CC XE now come in solids!
As far as the grind, deduct 12 degrees to compare to H. a 232 S is similar to a 220 H. This is because the lash reduces duration.
Next compare total cost to roller! Solid is a bargain!!!! :yesnod: In fact, flat tappet solids compete cost wise very well, great bang for the buck.
I urge everyone to take apart a H lifter. i just did. Quite a lot of parts to stick, tick, pump-up or bounce into the engine when the clip fails.
S=more reliable
Finally, S sounds cool!
Certainly no more noisy than any EFI multi-point! those injectors tick all the time on modern cars, and nobody tears them off swearing the tick drives them insane :crazy:

Fevre

Point well taken.

Now let's really open the debate, what about the variable lifters? I had a set in my 383 but not having run any other type, I have no idea if they do/did anything to improve my low end. If they function as advertised, but what does, they are supposed to reduce lift and duration. More I think about it, the less I like the idea. Seems anything that cause changes like that has to have weak points and I would imagine over time they would have durability problems. I think I am going to buy a solid cam for my 383 rebuild.

Oh ya, what about the retro fit roller lifters? Pricey but could be very interesting.

Matt Gruber

there is one convincing case FOR using H lifters :yesnod:
installed properly, they act as a rev limiter :smash: at about 6000 rpm they pump up,leave the valves open enough to kill rpm, and prevent serious engine damage :yesnod:
i had a solid engine years ago and the gas pedal got stuck to the floor, it was only a 6 cyl. Valiant, still it went to 8600 rpm!!!! then it bent 1 pushrod :smash:
Nowadays they sell electronic rev limiters for stick cars, and automatics can simply be left in Drive with the proper governor calibration.

The rev-limiting feature is a good one for those on a tight budget.

one last note, CompCams told me years ago that an equal solid cam was worth an extra 20hp over the H.

mountainmotor

Quote:
"Well, solid lifters, with no moving parts"

There are two designs flat tappet solid lifters available,one is a edge orifice design the other has a piddle valve inside which is a moving part,these piddle valve design lifters allow more oil up top to aid in cooling the valve springs in street applications or endurance racing

The Mushroom lifter was a good deal for it's day,now with better computer designed "plotted" cam profiles better progressive rate valve springs and the fact that the solid roller has over shadowed them they just are not in demand anylonger now that a harfaced cam and a chillied iron lifter to complement it is not a nessesity because of newer technology


[Modified by mountainmotor, 10:23 AM 7/4/2002]

Matt Gruber

mm
the ones i am looking at are the AT-992 the speed-pro cat. says:
"a patented oil metering system limits the amount of oil...
also
shows AT-840R Edge orifice type. Recommended for roller rocker arms.

thanks for pointing out the moving parts :cheers: and of course the one with the valve costs less :crazy:


[Modified by drives61, 12:20 PM 7/4/2002]

Edzred72

I am using Comp anti-pump lifters on a split duration 490-495 lift hydrol cam. I set them 1/4 past 0 lash, and got an audible tick from the start, but I have only about 1hr of running time on the motor after a top end build. Haven't had it on the street yet....
Eddie