Cylinder head for a gas engine and method of production

Gas engine having a plurality of cylinders and an air intake duct (3) for each cylinder, such duct having a gas injection channel (12) that passes through the wall (11) of the duct itself, preferably at the point of a fin-shaped protuberance (13). System used to supply gas to an engine, in which the gas is injected through the wall of an air intake duct of a cylinder.