INTAKE AIR PORT STRUCTURE OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To allow a tumbling flow to take place efficiently without causing any drop of a flow rate factor. SOLUTION: In the intake air port 10 of an internal combustion engine formed into a convex curved-shaped upward toward a combustion chamber 31 on the lower part from the upper side surface of a cylinder head, and in a curved part between the guide hole 11 of the valve stem 211 of an intake air valve 21 of the intake air port 10 and a valve seat part 12, a metal filling part 15 for changing the radius of curvature gently in a convex state toward the inside provided on the centrifugal side wall surface 101 positioned far away from the radius of curvature center O of the curve.