Variable valve timing mechanism

摘要

A number of embodiments of twin overhead cam shaft reciprocating machines having a plurality of poppet valves. A variable valve timing mechanism is interposed between the cam shafts and respective of the poppet valves for varying their lift and for changing the number of effective poppet valves per cylinder. The lift changing mechanism includes means for shifting at least one rocker arm follower and provides a relatively compact yet highly efficient structure for achieving this purpose.