Abstract: An impingement combustion chamber internal-combustion engine comprising mainly the piston, cylinder head and fuel injection. The exhaust side of a piston crown has a block-wall facing the spray direction of a fuel injection system. The top of the block-wall closely mates with the cylinder head. In the compression stroke, the piston moves from bottom dead center to top dead center and the nozzle fuel spray is injected to the block-wall. The fuel spray then absorbs high heat at the central portion of piston head to accelerate fuel vaporization. When the block-wall closely mates with the cylinder head, producing a high squish air motion, the fuel and air mix homogeneously, therefore, the air fuel mixture near the spark plug is easy to ignite and exhaust emissions are reduced.