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Discussion Starter · #1 ·
I just got a set of Crane lifters that are supposed to be anti pump-up but look just like regular lifters. They have a thin clip like a paper clip holding them together. I thought anti pump-ups were supposed to have a cir-clip holding them together.I'm afraid to use them as they don't seem right.Any insight on this?

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'58 Morris Minor 289 S/S MM
'62 Falcon 351W "Just Falcon Around"

<font size=-1>[ This Message was edited by: Just Jim on 6/25/02 9:35am ]</font>
 

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Anti-pump lifters from Crane look like regular lifters. They come standard with all there cam kits they sell. I hope you did not want there High Intensity lifters they sell. I think thats what they call them. They are like the Rhodes lifters that bleed down at low speed for added low end performance and pump up at high speed like a regular lifter.



Blue Fastback
 

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A true anti-pump lifter is a SOLID.

 

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Discussion Starter · #5 ·
I'm referring to anti-pump up lifters NOT Rhodes or fast bleed down lifters.I'm trying to gets some more revs out of the motor with the existing XE 284H cam without going to a solid cam.If the so called anti pump-up hi rev lifters work better than the standard type as they are supposed to then I'd be satisfied. I don't want to put the lifters in the motor unless they are actual high rev hydraulics which I'm not sure thay are.
 

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The most important thing in trying to get as many rpm as possible out of a hydraulic lifter, is to minimize the lifter preload. Use as little as possible... Use -just- enough to keep the lifters from ticking.

Regular rpm ranges can get away with up to a full turn, minimizing that to around 1/4 turn or less will give a few more rpm... at the possible expense of a little more noise.

What kind of rpm are you after? Are you sure it's the lifters cutting off the powerband, or could it be something else?

Good Luck!
 

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On 2002-06-24 23:14, Just Jim wrote:
I'm trying to gets some more revs out of the motor with the existing XE 284H cam without going to a solid cam.If the so called anti pump-up hi rev lifters work better than the standard type as they are supposed to then I'd be satisfied. I don't want to put the lifters in the motor unless they are actual high rev hydraulics which I'm not sure thay are.
Anti pump-up lifters are really something of a misnomer. No hydraulic lifters can actually PREVENT pump-up, because the problem is not with the lifters, it's with the other valve train components. What an "anti pump-up" lifter really does is allows a quicker recovery when valve train separation occurs.

"Valve float," as we typically call it, is in fact a situation where the valve spring force is unable to overcome the valve train acceleration inertia over the nose of the cam, and/or to prevent valve bounce off the valve seat when slamming the valves closed at high engine speed. In either of these situations, tension is momentarily lost between the lifter, pushrod, rocker arm, and valve tip...in other words, separation.

As tension is lost at "valve float" (again, really valve train separation), the hydraulic lifter does what it is SUPPOSED to do, that is takes up the slack in the valve train components by extending its internal piston via oil pressure. The problem occurs milliseconds later when the valve spring tension "catches up" to the inertial loads and re-tensions all the valve train components (violently, ouch!). Now, the lifter's push rod seat is in a different, higher position which causes the valve to be lifted higher than design spec (possible broken valve springs or piston to valve contact) and also holds the valve slightly off the seat when the lifter is on the heel of the cam...killing power.

This situation continues for the amount of time that it takes for the lifter's internal piston to bleed off oil pressure and return to its original height...from fractions of a second to several seconds. An "anti pump-up" lifter has a few ten-thousandths more clearance between the lifter body and the internal piston, allowing the lifter to bleed down to normal height more quickly.

So the "anti pump-up" lifter doesn't PREVENT this "pump-up" phenomenon, it just recovers more quickly (like immediately after shifting gears and the rpms drop enough to end valve train separation that occurs only when at peak rpm). This lifter functionality also explains why, on any hydraulic lifter, best high performance results are achieved by setting the preload as little as possible (i.e., 1/4 turn typical). The less difference there is between normal, running adjustment and maximum possible push rod seat height, the less the adverse effect of so-called "pump-up" when it does occur.

The important point is that lifters don't actually pump-up do to high rpm, they simply take up the slack when valve train separation occurs. The trick here is to use lightweight valve train components and the proper valve springs to prevent the valve train separation from occurring in the first place. Anti pump-up lifters are just a (good) insurance policy to minimize damage and loss of performance when separation does occur.

Now the nasty, unpleasant truth. Unfortunately, just selecting the proper valve springs to completely prevent valve train separation at your designated maximum rpm doesn't solve all your problems in a hydraulic lifter set-up. The rapid acceleration rates common in today's performance cams put the cam lobe contact point on the lifter way out at the outside edge of the lifter's diameter. This creates a lot of side-loading on the lifter against the lifter bore, which deforms the lifter body slightly. As a hydraulic lifter body deforms, the very precision fit between the body and the internal piston is trashed, and oil bleeds rapidly through the voids, allowing the push rod seat to drop. Hydraulic roller lifters, with their very fast ramp rates are also prone to this problem. Testing has indicated that high performance hydraulic cams may effectively lose as much as 15 degrees or duration and significant amounts of lift as they approach their maximum operating rpm, due to this body deformation and bleed-down. It's a trick box; the more valve spring pressure you use to prevent valve train separation and lifter "pump-up," the worse the side loading becomes. Conversely, lightening the valve spring pressure to maintain spec lift and duration at max rpm will create enough valve train separation to allow the "pump-up" phenomenon. You can't win, from a pure performance standpoint.

What's the answer? Simple choice. Flat tappets or rollers, either live with the limitations of hydraulic lifters and enjoy the convenience, or go to solids for maximum all-around performance.

Steve A.

<font size=-1>[ This Message was edited by: amossm on 6/26/02 1:25am ]</font>
 

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Not sure this has beeen stated, but.....

the main difference between an anit-pump up lifter and a standard hydralic lifter is internal....the oil bleed metering hole is smaller and positioned differently in most cases...

without taking it apart, you can't tell the diff most times.
 

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Actually, valve float and lifter 'pump-up' are two different things.

Valve float occurs when engine spins fast enough that the valve spring can no longer control things. The intertia of the valvetrain simply exceeds what the spring can control.

Pump-up is different, and occurs with hydraulic lifters only. Hydraulic lifters have a plunger that is depressed a small amount (lifter preload) for normal operation. Most people deperss the plunger between 1/4 and 3/4 turn past the point all the slack it taken out.

At high rpm, when oil flow is high, and bleed down time is low, the lifter can effectively turn 'solid' and the valves will not close all the way. In mild cases, the engine just quits pulling. If very much preload is used, and/or clearances are tight, this can result in bent valves.

I recommend solid cams for anything over 6k rpm.

Good Luck!
 

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Discussion Starter · #10 ·
Thanks for all the info guys. Lots of good info there.

I tried to buy some Ford Racing anti-pump ups today from R&E Racing and they were out of stock for those and Comps.Seems this lifter company closing down business talked about on another post IS causing availability problems.

Before I use the Cranes I'm going to compare the internals with a regular aftermarket lifter I have from a previous project.

I know to get more revs a solid cam is the way to go what I don't understand is how most cam companies list more than one hydraulic cam with so called usable RPM of up to 6500-6800.If they won't rev that high why do the cam makers list them as such?All I want is to rev the motor to 6500 with the new lifters. If it makes more power fine if not that's fine too. The springs check out good so they aren't the problem.
 

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I don't know about all that tech stuff but
I take my 292/.512 Lunati hyd. cam and Crane anti-pup lifters and Comp rail rockers to 6500 rpms on a regular basis at the strip and once ran 7000 rpms for 10 miles in a road race with a Vette. I do all this with 100# springs and pressed in studs.

Just be sure that you have a deep sump oil pan if running a HV pump cause it will pump a stock pan dry at 6000. You also may need a high energy ignition coil cause my stock one gave up at around 6200.

Have fun!!
 

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bluestreak did you beat the vette or at least scare the fire out of him?
 

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I seem to have one lifter that is bleeding off after two weeks or so of not running. It makes a clacking sound when started and lasts for 15 minutes or so then goes away until the car sets for two weeks or so. I am running dual springs to rev it past 6K. Should I change just the one lifter or change them all or not worry about it until later? What could happen if the lifter is not changed?
 

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Discussion Starter · #15 ·
I still have the brand new Crane anti pump up lifters mentioned almost 5 years ago in this original post. Never used them.
 

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Super Stock Industries makes a Heavy Duty Anti Pump Lifter, offered by P.A.W. for 5.95 each. They set at zero lash with adjustable rockers only, flat tappet!
 
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