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On 21 Feb 99, at 2:13, oofacts@earthlink.net wrote: > Someone want to give me a simple explanation of Hydraulic lifters? What do > they lift? What are they hydraulic, as opposed to... Mike, You really need to condense your questions! Lifters are also called cam followers. Stock VW lifters are solid pieces of steel that follows the cam lobes up and down, transmitting that motion to the pushrods, rocker arms, and valves. They have to be adjusted to have a slight bit of play, or extra room. Hydraulic lifters provide the same function, excepQ ì hey consist of several parts which nest together. As assembled dry, these parts are spring loaded and they would just compress as the cam lobe came up, however, in use they are filled with oil which can't escape fast enough to allow the hydraulic lifter to collapse. The only escape path is a tiny hole from which oil can pass only slowly. This path still allows the lifter to change length slowly so that it can adjust for the very small changes in length as your engine warms up. Our engines were not designed with hydraulic lifters and what I have always heard is that the VW oil pressure is too low to support a typical hydraulic lifter. While the appeal of a lifter that automatically adjusts, thus eliminating valve adjustments, is obvious, I don't think any of the truly reputable places sell them yet. Also keep in mind that for high RPM, high performance engines, hydraulic lifters are universally dropped in favor of solid lifters. Jim - ******************************* Jim Adney, jadney@vwtype3.org Madison, Wisconsin, USA ******************************* ------------------------------------------------------------------- List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org