INTAKE PORT STRUCTURE FOR INTERNAL COMBUSTION ENGINE

In an engine (), an ignition plug () is arranged between a first intake port () and a second intake port (). In a case where a downstream end portion () of the second intake port () is divided into a first intake port () side and an opposite first intake port () side, an inner wall surface () of an opposite first intake port () side portion extends in a direction toward the first intake port () as extending from an upstream side to a downstream side of the second intake port ().