| 摘要 |
PURPOSE:To cool the portion facing each cylinder impartially and effectively by providing a cooling air inlet on an intake port side and forming a cooling passage for pouring cooling air from said inlet to an exhaust port side through said portion in parallel. CONSTITUTION:A cooling air inlet 30 is formed on an intake port side 15 of a cylinder block 1, opens to the under side of a cylinder head 13 positioned below the intake inlet 15, and communicates with a cooling air passage 20 formed by a cooling air guide 16. And the cooling air inlet 30 is communicated with a first passage 31 between valves extending from the periphery of a fuel injection valve inserting hole 27 of a first cylinder 8 to the counter side through the space between an intake and exhaust valves, a passage 32 between cylinders passing through the space between an exhaust passage 28 of a first cylinder 8 and an intake passage 35 of a second cylinder 9 and going through the counter side, and a second passage 33 between valves going through the space between the intake and exhaust valves from the periphery of fuel injection valve inserting hole 27 of the second cylinder 9, respectively. |
