[T]he valves, which open and close to let the air-fuel mixture in and out of the cylinders, are above the camshaft, which is in the engine block. The camshaft activates pushrods that move up and ...

Yeah, weird stuff. The camshaft is also centrally located in the crankcase and still runs at 50-percent crankshaft speed but only actuates one valve per cylinder, something that even when this ...

IN THE usual auttmobile poppet valve the poppet or mushroom valves are lifted from their seats by cams and reseated by springs. In a four·cycle motor, the valves in each cylinder are Oiened and ...