Internal combustion engine having at least one cylinder head, which - has four cylinders arranged in series along the longitudinal axis of the cylinder head, each cylinder having at least one exhaust port for discharging the exhaust gases from the cylinder via an exhaust system, for which purpose each exhaust port is adjoined by an exhaust line; wherein - the exhaust lines of the cylinders come together in stages to form an overall exhaust line, the at least one exhaust line of an outer cylinder and the at least one exhaust line of the adjacent inner cylinder in each case coming together to form a partial exhaust line within the at least one cylinder head before the two partial exhaust lines of the four cylinders (3, 3a, 3b) come together to form an overall exhaust line; wherein - the exhaust system emerges at an outer side of the cylinder head; and wherein - the outer wall sections, which in each case separate a section of the at least one exhaust line of an outer cylinder and a section of the at least one exhaust line of the adjacent inner cylinder from one another and which project into the exhaust system, extend less far in the direction of the outer side of the cylinder head, perpendicularly to the longitudinal axis of the cylinder head, than the inner wall section, which separates a section of the two partial exhaust lines and a section of the exhaust lines of the two inner cylinders from one another and projects into the exhaust system, characterized in that the inner wall section as well as the outer wall sections are formed integrally with the cylinder head, wherein the partial exhaust lines outside the at least one cylinder head come together to form an overall exhaust line, and wherein the inner wall section, which projects into the exhaust system, extends up to the outer side of the at least one cylinder head or beyond the outer side of the at least one cylinder head. - has four cylinders arranged in series along the longitudinal axis of the cylinder head, each cylinder having at least one exhaust port for discharging the exhaust gases from the cylinder via an exhaust system, for which purpose each exhaust port is adjoined by an exhaust line; wherein - the exhaust lines of the cylinders come together in stages to form an overall exhaust line, the at least one exhaust line of an outer cylinder and the at least one exhaust line of the adjacent inner cylinder in each case coming together to form a partial exhaust line within the at least one cylinder head before the two partial exhaust lines of the four cylinders (3, 3a, 3b) come together to form an overall exhaust line; wherein - the exhaust system emerges at an outer side of the cylinder head; and wherein - the outer wall sections, which in each case separate a section of the at least one exhaust line of an outer cylinder and a section of the at least one exhaust line of the adjacent inner cylinder from one another and which project into the exhaust system, extend less far in the direction of the outer side of the cylinder head, perpendicularly to the longitudinal axis of the cylinder head, than the inner wall section, which separates a section of the two partial exhaust lines and a section of the exhaust lines of the two inner cylinders from one another and projects into the exhaust system, characterized in that