[Formulabruce]

THIS, a Good read, dated 2012....Hot rod bulletin board... I went to visit a guy who had this same problem, took out the high pressure pump spring and back to stock, and Mexico Lifters and it was good....
>> " The major U.S. manufacturers of hydraulic flat tappet lifters are now Johnson Tappet, Hylift-Johnson, a division of Topline Inc., and Delphi.

The major 'offshore' producer of lifters is currently Eaton with plants in Mexico, India, Turkey and a new plant in China.

Be advised that Johnson Tappet DOES NOT make a Pontiac specific flat tappet lifter. Johnson tappet DOES make a universal, high-band lifter that will work in some Pontiacs, under part 4114, but it is NOT a Pontiac specific item.

IF you are buying a 'Johnson' Pontiac lifter, it is NOT made by Johnson and is a counterfeit, or re-boxed Eaton lifter - period.

This was confirmed by Johnson Tappet's Product Manager Joe Lewis.

Comp's 852 is currently a Delphi lifter, according to Comp's Scooter Brothers and David Butler. This is said to be a quality lifter and is Pontiac specific in its configuration. However, Comp recently announced they are dropping Delphi as a supplier and are yet to announce their new supplier.

Hylift-Johnson does make a Pontiac specific hydraulic flat tappet under Part #A-0951 and #A-0951R. Hylift-Johnson is the source for Summit and Jeg's house brand hydraulic flat tappet lifters. These seem to be a good lifter and are 100% U.S.A. made from U.SA. materials.

Topline, who owns Hylift-Johnson, has recently discovered knock-off versions of their lifters in circulation, complete with counterfeit packaging and phony SKUs. Out of 30 recent returns of Jeg's lifters, none were Hylift-Johnson's and all appeared to be the result of the practice of 'rebox rotation' by consumers, substitutig stock used and 'Brand-X' lifters due to Jeg's liberal return policy.

Hylift-Johnson maintains that the big lifter "problem" first began when Standadyne started using "offshore raw materials" around 2006 and thus all the failed lifter bodies were blamed on reduced Zinc levels in the oil, which wasn't the problem at all.

All of this was confirmed by Topline's General Manager, David Popp, who also advised that Hylift-Johnson is the source for all of Rhoad's component parts; a fact later confirmed by Rhaod's.

According to several of my industry sources, the Eaton lifters should be avoided, but it's not quite that easy and definitely not the end of the story.

My problems started when I ended up with a set of 'L-951' hydraulic lifters, which turned out to be an Eaton product. Eaton makes them for Melling, Federal-Mogul, Sealed Power and Engine Tech at their plants in Mexico, India, Turkey and most recently, China. Most of these lifters carry the 'L' designation in their part number, but the same lifters are also marketed under part numbers JB-951 and HT-951.

While many folks do claim good luck with the "Hecho En Mexico" Eatons, and I do not doubt that some of these lifters are providing good service, I had some real problems with the set that I obtained.

Of interesting note, Hylift-Johnson has offered to perform an autopsy on these L-951s and provide a full written report as to their findings, but here are the preliminary issues I experienced.

These lifters would hammer until the motor warmed up and then would be dead quiet. No matter how they were adjusted, zero lash, one-quarter turn, one-half, three-quarters and 1 full turn, the noise persisted. When I first backed the adjustment off to one quarter turn, I told Jim Lehart that the problem was fixed, but the noise returned after 24-36 hours of sitting.

After 800 miles of highway time on the new 413 Pontiac, I knew the problem wasnt going away. Oil analysis revealed wear metal numbers lower than standard for a rebuilt engine and the quiet nature of the top end when hot suggested the lobes were OK.

So, as long as the engine was warm, the top end was quiet. As an experiment, I switched from Valvoline 20w50 to Valvoline 10w30 with no improvement. I tried using Bosch, Fram, WIX and AC oil filters with no improvement.

Oil pressure at the filter housing and the drilled passage beneath the distributor were 30 psi/60 psi hot and both within 2-3 psi of each other at both locations - all the time.

On a technical note, the rear oil galley plug is present and visible through the distributor opening and both sides of the motor oils wildly once the temps come up.

The valve springs used are an Isky #5105 dual w/damper installed at 1.687 with 100 lbs seated and 265/270 lbs open. The lifters had the correct oil band location and micd out to .842 in diameter, but I knew something wasnt right.

After pulling the valley pan and lifters, I found a perfect UD 231/235-110 camshaft, despite many hours of hammering when cold. The lifters also looked perfect. Out of pure curiosity, I decided to run the oil pump with the lifters installed without pushrods.

To my amazement, oil would flood out of the lifter, between the plunger and body, but nothing came out of the oil hole or between the lifter body and the block!!!!

It seems that the plunger/barrel clearance is excessive and is allowing the oil an "escape path" before it can get through the piddle valve and up to the top end. I can only assume, in the absence of a small enough inside mic, that this clearance is closed up, to some degree, by heat, at which time the lifter then functions normally.

When I dropped in a SUM-951 lifter, it oiled wildly through the oil hole immediately.

Interestingly, while poking around on the Internet, I found an old archived post about a similar problem with a Pontiac 455, which I have posted for your information and review below:

"I just built a fresh 455. New Comp Cams Extreme Energy, Lifters are Comp Cams 852-16. Upon priming the oil system, no oil comes out from the new roller rockers, or even up the pushrods. I removed one lifter and replaced it with my old H-O Pontiac lifter with the snap ring retainer. On priming, that pushrod and rocker arm gets plenty of oil now......"

In more recent discussions, I have had several people tell me they have replaced Comp 852s in their Pontiacs because they didnt oil correctly to the top end, a problem which disappeared when a different lifter was employed.

I have also had people tell me they are very pleased with the "Hecho En Mexico" Sealed Power and Federal Moguls.

Now it would seem that this is no longer a simple matter of not using an Eaton lifter, as it appears to be affecting Pontiacs en masse."