A computer simulation has been modified to study the effects of valve event parameters (lift, duration, and phasing) on spark-ignition engine performance. The zero-dimensional model employs polynomial and dynamic techniques to generate cam profiles for valve event optimization. The model was calibrated and validated against data from a General Motors 2.5-liter engine. The simulation was then used to determine optimum valve events under different engine conditions. This insight was used to improve the cam design. Subsequent engine testing confirmed that a 3 percent improvement in peak torque could be obtained with the optimized cam.