A small gap with big importance in the performance and health of an engine - here's everything you need to know.

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, ...

On engines equipped with hydraulic tappets, zero lash at maximum tappet plunger rise can be determined by rotating the pushrod with your fingertips while slowly turning the lash adjusting nut. The ...

Does your engine need a valve adjustment? It depends on the age, condition and brand of vehicle you’re driving. Due to the popularization of roller-follower valve train designs that reduce friction ...