Gas motion within the cylinder is one of the major factors that control the combustion process in spark ignition
engine. It also has significant impact on heat transfer. Both the bulk gas motion and the turbulence characteristics
of the flow are important and governing the overall behavior of the flow. An arrangement for obtaining a stratified
charge, using port injection, is proposed for a current design of a spark ignition engine. The behavior of combustion
are simulated with Computational fluid dynamic and tested. Engine testing was performed using dynamometer
for measuring the lean burn limit of the current spark ignition engine. Some concepts for premixed lean burn are
introduced during the previous decade and with this state of the art concept the swirl and tumble flow pattern can
generate in each speed, therefore the effect of these pattern on lean burn limit is investigated.