Hydraulic lifters?

IMHO, a bad idea.

This is what I've heard... Do not consider my opinion as "the" truth.

Hydraulic lifters require exacting tolerances to work properly, but as the engine is air-cooled rather than liquid-cooled, the operating tolerances can't be met due to the wide temperature range.

That's the summary, but I don't know the details.

I used to own an '89 Mazda 929 with a V6 that had hydraulic lifters. When the oil got dirty, the valvetrain got loud. It was a great indicator when to change the oil, but not a good design cause the check valves are too sensitive to the quality of the oil. I heard all Mazdas where that way.

Don't do it. My reasons:

1) hyd. lifters require a different grind than solids. 2) No performance gain. 3) No performance cams available. 4) cost. 5) They require a filter and/or they get stopped up easily. 6) They Suck. 7) Experience, had a motor with them, nothing but trouble. 8) Noisy 9) etc...

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The above is pure myth.

Air cooled aircraft were among the first applications of hydrualic cam followers (ie, 'lifters').

The various 'drop-in' hydrualic lifters for VW engines (CB, etc.) didn't work simply because the right side of the engine receives ALL of its oil via the #2 cam bearing web and the supply was simply inadequate for the 'corner' lifters.

Equally mythical is the tale about poor high-speed performance from juicers. Testing crate engines from the Puebla plant, two with solids and one with juicers, the latter dyno'd 3hp above one of the others and 5hp above the other, apparently because of the constant zero-lash on the valves.

Couple that with the fact juicers do not require periodic adjustment... plus the fact all modern engines use them... and you really have to work to find a valid reason for not using them.

But of course, all that violates that lovely 1930's-era Conventional Wisdom that sez hydraulic lifters are bad, bad, things.

Thinking for yourself is a barbed wire T-shirt and clean-climbing an icy rock face. Following the herd is a warm, fuzzy blue blanket.

Take your pick.

-Bob Hoover

Humm... I run zero lash now. :)

On Sun, 18 Jan 2004 18:03:51 -0600, snipped-for-privacy@xyzzy.stafford.net (jjs) ran around screaming and yelling:

me too...but only when cold.... J

Bob, an curious as to what aircraft engines used hydraulics. AFAIK Cadillac was the first (American anyway) to use hydraulic "silencers" in thier V12 or V16s back in the 1930's.

-ANT

Stop that. To reply change my ISP to @hotmail.com

All men are equal at forty below zero.

I'm not a mechanic, but I've had a couple of Buses with stock hydraulic lifters and I've had no problems relating to them - and I've never adjusted the valves. That said, I've never considered putting them on my Type 3 engines - although I've wished they came stock with hydraulic lifters.

So what do the Mexican juicers do differently to make the right side oiling work well enough to support hydraulic lifters?

Can any of this be retrofitted to old VW aircooled engines?

-

----------------------------------------------- Jim Adney snipped-for-privacy@vwtype3.org Madison, WI 53711 USA

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On Sun, 18 Jan 2004 19:17:15 -0600, snipped-for-privacy@xyzzy.stafford.net (jjs) ran around screaming and yelling:

hmm...at that temp, i'd say all men are damn near women...LOL J

notice the word "mild".

If the engine is built to top out before 6000rpm it will be okay with hydraulics I think. Not sure though, I never tried it myself.

Jan

Yes there are.

A performance engine would have full flow oil filtration anyway, makes no sense to build one without...

God info Ben. I'm leaning towards "Don't".

Jan

Mmmmmmm... warm fuzzy blue blanket........

Jan

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Same thing we've always done :-) (and which I've mentioned here before) Go see the HVX Mods in the archives of the AirVW Group on Yahoo.

-Bob Hoover

I had the Mexican motor as well. I bought it with very few miles. The top end rattled like a diesel from the start. I adjusted the valves several different ways as suggested here in this group. Could never get them to quite down completely. The engine lost a wristpin retainer shortly after install so I got to tear it down and get a good look.

The lifters were from a type 4 and the lifter bores were quite a bit thicker. I considered going to solid lifters but another $80 for new lifter

• or so for custom pushrods did not suit the budget. So I had the bottom end rebuilt by a reputable builder. After reinstall it lasted 50 miles or so before locking up, still rattled. One might say that there were other problems or it was built wrong but in 20 years of messing with VW's I have only had one other motor lock up and it was wore out.

Now chances are I got a lemon and probably they are not all like this one. But I did learn allot about hydraulic lifters. Like most things, if done correctly they are probably ok. But I found it hard to find any definite answers about anything, from adjustment to different cams available. True, the juicers work great in a type 4, but then that motor was designed for them.

I think if I were to try it again I would build a type 4 upright. The benefits (no valve adj0 JUST DO NOT OUTWEIGH THE PROBLEMS.

Ben

Well, thank you RAMVA for the numerous responses....I have been convinced to continue checking and adjusting my valves. Thanks again for all the info and opinions.

"Joey Tribiani"

| around screaming and yelling: | | >All men are equal at forty below zero. | | hmm...at that temp, i'd say all men are damn near women...LOL

Espically HOT women.