Valve system dynamics must be first analyzed before engine valve mechanism can be designed . Traditional valve design must stick to a fixed mechanism . This thesis proposed a new valve design with variable mechanism . Softwere Package ADAMS was used and the feasibility of this new mechanism was analyzed , also the parameters effect were discussed . The parameters include shape, mass, rocker arm and valve displacements . The simulation results show that this new variable mechanism design is feasible . Also the Softwere Package help making the simulation faster and more accurate .