The aim of this study is to investigate the effect of spark advance on engine performance parameters in a twin spark SI engine. Quasi-dimensional thermodynamic engine cycle model has been used in the study. Flame propagation process in the simulation has been modeled by solid model software. Equivalence ratio (.), three various locations of the spark plug(s) on cylinder head, and mainly spark advance has been operating parameters of the study. It has been determined that the geometry having centrally located spark plug(s) gives the best combustion and performance characteristics from the results of the study. Using of twin spark plugs gives closer combustion and performance characteristics due to increasing combustion speed. The mid-radius located single spark geometry gives the worst characteristics since it has the longest flame travelling length.