Mechanical lifters were once commonplace in internal combustions engines, but they've been mostly replaced by hydraulic ...

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 ...

From the archives: The beauty of hydraulic lifters is that they self-compensate for valvetrain clearances, doing away with the need for valvetrain adjustment. To celebrate HOT ROD's 75th anniversary, ...