Definitions for "VALVE LIFTER"
Engine valve train component that bears directly on the cam, opening and closing an intake or exhaust valve.
Also called a "valve follower": the cylindrically shaped component that presses against the lobe of a camshaft and moves up and down as the cam lobe rotates. Most valve lifters have an oil-lubricated hardened face that slides on the cam lobe. So-called "roller lifters", however, have a small roller in contact with the cam lobe: thereby reducing the friction between the cam lobe and the lifter.
see hydraulic lash adjuster