A Novel Continuously Variable Desmodromic Engine Valve Timing Mechanism

This paper introduces and illustrates the design concepts of a novel continuously-variable valve duration and timing mechanism. This totally mechanical design is adaptable to existing spring-loaded poppet valve systems and may also be used in desmodromic form. The design can simultaneously and/or independently control intake and exhaust valve opening and closing, allowing the valve duration window to be moved to any point in the operating cycle of the engine. Preliminary calculations of the optimum cam profile for this mechanism were obtained using a computerized engine-simulation program.