The rules in some racing classes restrict competitors to running hydraulic valve lifters. Cheaters have been known to run hydraulic lifters on a mechanical (solid) cam profile. Solid cam profiles ...

At the very least, tearing down, inspecting, and cleaning hydraulic lifters is good engine hygiene that can contribute to long service life in your classic car. It’s also a great way to inspect the ...

COMP Cams Explains the Pros and Cons of Solid, Hydraulic, Flat-Tappet, and Roller Cams, and the Advanced Technology that makes them all Work. With horsepower seemingly growing on trees these days, ...

It is possible to run solid flat tappets on a hydraulic flat-tappet cam and even mechanical roller lifters on a hydraulic-roller cam. Putting solid lifters on a hydraulic cam will gain about 500 rpm ...