Air intake system for an IC engine

The air intake for a motor vehicle internal combustion engine has two inlet ports (2,3) with their openings disposed so that a line joining the center of each opening in a plane perpendicular to the cylinder axis (1) forms an angle of thirty degrees to ninety degrees with the opposing face of the cylinder head (4). At least one passage is divided by an internal partition (10,11). Closures (12,13) are adjustable to progressively close the passages.