Hydraulic lifters

Can anyone explain in plain terminology what hydraulic lifters are? I'm finally getting my engine problems sorted out. After taking apart the engine and finding that one of the screws was put in backwards (by the builder!), I had a rocker assembly replaced and the screw put in the correct way. The mechanic then tried a valve adjustment and after having a bit of trouble realised that I had a VW engine with hydraulic lifters. He said I will never have to do a valve adjustment. I had never heard of this change to the basic VW engine, although I don't really know anything about the car anyway. Any info shared would be appreciated. Thanks again.

I'm a little surprised that he didn't know you had hydraulic lifters. Most people shy away from them on aircooled engines because if the lifter goes "flat" you have to split the case to get it out. I am assuming you have a type 1 engine?

From another site:



"LIFTERS: These the fit between the cam and the pushrods. There are essentially two types. First is solid. These are ???. They allow for more accurate following of cam profile at higher RPMs. They also require periodic adjustment. The other type is hydraulic. These use engine oil to obtain proper height. There are variations on the hydralic lifters. One is a Rhodes style lifter. These don't obtain full height at low oil pressures allowing a more radical cam to be run and maintain drivability.
The other variation is roller lifters. These have a roller that runs against the cam. This provides lower friction, but requires a cam designed for these lifters."


A simple beginning for an interesting and sometimes complex discussion. Along with the various lifters, you get to play with cam profile, running a hydraulic cam with solid lifters and rocker shims and vice versa, valve lash, lash caps thicknesses, engine expansion rates, valve sizes and rocker ratios, engine longevity, and so on . . .

A simple beginning.

Luck !

TC

Another consideration. From my readings it seems converting the case to accept hydralic lifters requires boring what some writers call the lifter "bosses" (the area where the pushrod hydralic device connects to the case). This reduces the case "material" in that area and weakens the case. Type I cases were originally designed for solid lifters. I believe in Mexico and Brazilian production they have used hydralics, but I think in even in these production models they may find them to be a source of problems.

Well, mine came in what I assume was a stock Vintage with what I believe is one of the Mexican built 1776 motors. If all the Vintage's have these, how come I have never heard of them before. Don't get me wrong, less maintenance is fine with me. I was just a little dumbfounded after reading here for more than a year about "how to do valve adjustments" and I know the guy I bought it from did one and now this VW mechanic (he's got engines all over his garage and a great running bus and a Beetle that's tricked out for ice racing) tells me I don't need to do them.

The more I learn, the less I know.

Luke, I think with Vintage it's optional. The first owner may have specified hydralic lifters. I think Vintage will let you opt into a rebuilt motor, a new factory built motor, or they will install a motor you have delivered to them. Better check with Kirk if you want to know more than the original owner told you.