Internal combustion engine

摘要

An internal combustion engine is disclosed which includes a plurality of cylinders split into first and second groups and operates in a split cylinder mode under low engine load conditions where the second group of cylinders are held inoperative and have their intake and exhaust ports connected to each other. Means is provided for preventing exhaust gases discharged from the second group of cylinders from mixing with exhaust gases discharged from the first group of cylinders during the split cylinder mode of operation.