Bridge and pivot foot arrangement for operating engine cylinder valves

A method of making a valvetrain of an internal combustion engine having one or more engine cylinders within which fuel is combusted to run the engine and a pair of cylinder valves that are associated with each of one or more of the cylinders and that are spring-biased closed but are operated open in unison to place the respective cylinder in flow communication with one of an intake through which intake flow can enter the respective cylinder and an exhaust through which exhaust flow can exit the respective cylinder, the method comprising fabricating a metal bridge for bridging ends of the respective pair of cylinder valves external to a respective cylinder to create in one face of the bridge a pair of blind holes for receiving the ends of valves and in an opposite face a spherically concave depression intermediate the blind holes, fabricating a pivot foot that has a spherically convex surface whose radius substantially conforms to that of the spherical concave depression, placing the spherically convex surface of the pivot foot in surface-to-surface contact with the spherically concave depression, placing the bridge to receive the ends of the valves in the blind holes, and placing the flat surface of the pivot foot in surface-to-surface contact with a flat surface of a rocker that is effective to open the valves in unison via the pivot foot and the bridge.