US Patent 7296560 Engine of spark-ignition type

An engine of spark-ignition type injects fuel from an injector (3) into an intake port (2) provided in a cylinder head (1). In this engine of spark-ignition type, the injector (3) has fuel injection holes oriented toward an inner wall surface of the intake port (2) and makes a start (3a) of the fuel injection during an exhaust stroke of each of cylinders (5) and (6). The injected fuel is adapted to collide against the inner wall surface of the intake port (2). Preferably, the start (3a) of the fuel injection is made at a later half portion of the exhaust stroke of each of the cylinders (5) and (6). More preferably, the start (3a) is made during a term of 31 degrees to 25 degrees of a crank angle before the end of the exhaust stroke.