PURPOSE: To prevent exposure of the combustion chamber outer wall by providing partition walls to the cooling jacket, while said walls being higher than the combustion chamber outer wall and lower than a liquid surface sensor position.
CONSTITUTION: A cooling jacket 1 formed on the cylinder head of a boiling-cooling system engine is provided with partition walls 5 sufficiently higher than the combustion chamber outer wall 3 and lower than the position of a refrigerant surface sensor 6a and vertically standing toward an upper side steam chamber 7 at the position of each intermediate outer wall 4 of the combustion chamber. The partition walls 5 are constructed in a monoblock casting together with the combustion chamber outer wall 3 so that the walls 5 are connected to both right and left walls. By this construction, the combustion chamber outer wall 3 is privented from being exposed when the vehicle is inclined or is turning.
KINDOU MASAHIKO
KUBOTSUKA TAKAO
