VALVE LIFTER

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. Also called "valve follower" or cam follower .