Apparatus and method for measuring valve lash

A valve lash measurement device is provided for an internal combustion engine having an articulated valve train including a rocker arm having a bore at one end that receives a valve abutting shoe having an uneven surface. A fixed geometry reference surface is attached to a spring loaded base insertable into the bore. A weight connected to an arm and hook with a fulcrum in between is movable along a reference plate to pivot the rocker arm between its extremes of movement. A dial indicator abuts the reference surface and indicates the relative displacement between the extremes of movement and therefore the lash.