Patent ID: 8555853

Claim:
An internal combustion engine including a pair of adjacent cylinders, each one of said pair of adjacent cylinders comprising: a piston; a first intake valve; a second intake valve; a primary port associated with said first intake valve; and a secondary port associated with said second intake valve; each of said ports being configured to provide a predominant direction of airflow therethrough during engine operation when viewed from above said cylinders, said ports being effectively oriented to provide respective in-cylinder air-swirl of opposite direction in each one of said pair of adjacent cylinders during an intake stroke of a respective piston; wherein the respective ports associated with each one of said pair of adjacent cylinders are configured so that an angle of intersection between the predominant direction of airflow through the respective primary port and the predominant direction of airflow through the respective secondary port is any angle in the range of between 10 degrees and 45 degrees, including all angles and ranges of angles therebetween, when viewed from above said cylinder.