INTERNAL COMBUSTION ENGINE

摘要

In the invention, in an upstream portion from a valve connecting surface (41) that is formed in an opening of an intake port (4) to a combustion chamber (8), an upper wall surface (42) of the intake port (4) continues from an upstream side end (41a) of the valve connecting surface (41) and extends substantially straight and diagonally with respect to a ceiling surface (8a) on the intake port (4) side. In addition, a cross-sectional shape of the portion in the intake port (4) in a direction perpendicular to an axial direction of the intake port (4) is a flat shape with an axis in a transverse direction being a long axis.