The engines of yesteryear were pretty simple, with tappets clackity-clacking away on cam lobes, opening valves, and making a ruckus while doing it. Mechanical lifters were adequate for valve operation ...

Editor's note: I met Jack Rhoads in 1967 when his father, James, conceived of a then-revolutionary way to vary valve timing as a function of engine speed. Today the concept is as valid as it was back ...

Riding on last month's How It Works topic (cams) is this month's topic—lifters. These cylindrically shaped components contact the lobes of the cam to convert the eccentric shape of the lobe into ...