Finger follower rocker arm with engine valve deactivator

A self-contained engine camshaft cam lobe actuated finger follower type rocker arm assembly for drop-in installation in an engine, comprising, a longitudinally extending outer hollow body engagable adjacent one end with an engine valve stem for actuation thereof, moveable lash adjuster pivot fulcrum means adjacent the opposite end, and lost motion arm means pivotally mounted to and within the body adjacent the stem engaging body end, spring means urging the lost motion means into engagement with a rotatable cam lobe, means mounting the arm means for a pivotal arcuate movement of the arm means by the cam lobe relative to the body preventing actuation at times of the valve stem by the body upon movement of the arm means, and latch means wholly contained within the lash adjuster end of the body extending essentially parallel to the body longitudinal axis for movement in opposite directions, the latch means including a plunger means projectably movable longitudinally to a latch position into the path of arcuate movement of the arm means for engagement therewith thereby preventing relative movement between the body and the arm means in one direction to thereby transmit movement of the arm means by the cam lobe to the body for actuating the valve stem, the plunger means and arm means having engagable mating flat surfaces providing wide surface area contact when engaged while permitting limited sideways movement therebetween thereby minimizing contact stresses therebetween and the need for precise thrust surfaces.