EXCITE Timing Drive is used in the design and analysis of valve trains to meet the requirements of dynamics and durability whilst reducing friction and noise excitation. The output shows the dynamic components of all modeled valve train elements. The periods of contact loss between single valve train elements, the dynamic behavior during valve open phase, and impact forces at valve closing can be determined. The results include the excitation forces causing vibration and noise of the engine structure. Therefore, the results can be used to assess modifications of cams and valve trains with respect to dynamic loads, valve timing and noise due to impacts in the valve train. The real valve train is described by a lumped mass system. Because of the non-linearity, the dynamic behavior (motion, forces) of the elements of this system is calculated in time domain by step-by-step integration using a second order Predictor/ Corrector method. Calculated are the dynamic paths, velocities, accelerations, and forces in the valve train elements. Cylinder pressure, friction at various elements and speed irregularities of the camshaft can be EXCITE Timing Drive provides generic elements (rigid body, general connections) and specific elements. Generic elements are used to perform more detailed analyses of valve trains, timing drives or parts of overall systems if required, as well as to investigate new design concepts and to simulate other kinds of mechanical systems. Specific elements are prepared to cover common valve train components. They require a reduced amount of input data and can easily be used for most usual timing