Cooling system for small watercraft engine

A small watercraft comprising a hull defining an engine compartment, an internal combustion engine disposed in the engine compartment, a lubrication system arranged to supply lubrication oil to the engine and comprising a reservoir at least partially defining a space for holding lubrication oil therein, a first cover member connected to an outer surface of the reservoir to define a first cooling jacket portion therebetween, a second cover member connected to an outer surface of the reservoir opposite the first cover member, the second cover member and the reservoir defining a second cooling jacket portion therebetween, a first transverse passage and a second transverse passage connecting the first and second cooling jacket portions, the first and second cooling jacket portions and the first and second transverse passages at least partially defining a cooling jacket of the reservoir, an inlet and an outlet in fluid communication with the cooling jacket, a cooling system arranged to supply cooling fluid to the inlet and receive cooling fluid from the outlet, the cooling jacket including a plurality of horizontal passages and being configured to guide a flow of cooling fluid between the plurality of horizontal passages, additionally comprising an inlet passage communicating with the inlet and defining a first cross-sectional area, the horizontal passages generally defining a second cross-sectional area substantially equal to the first cross-sectional area.

A small watercraft comprising a hull defining an engine compartment, an internal combustion engine disposed in the engine compartment, a lubrication system arranged to supply lubrication oil to the engine and comprising a reservoir at least partially defining a space for holding lubrication oil therein, a first cover member connected to an outer surface of the reservoir to define a first cooling jacket portion therebetween, a second cover member connected to an outer surface of the reservoir opposite the first cover member, the second cover member and the reservoir defining a second cooling jacket portion therebetween, a first transverse passage and a second transverse passage connecting the first and second cooling jacket portions, the first and second cooling jacket portions and the first and second transverse passages at least partially defining a cooling jacket of the reservoir, an inlet and an outlet in fluid communication with the cooling jacket, a cooling system arranged to supply cooling fluid to the inlet and receive cooling fluid from the outlet, the cooling jacket including a plurality of horizontal passages and being configured to guide a flow of cooling fluid between the plurality of horizontal passages, wherein the plurality of horizontal passages are at least partially defined by a first plurality of ribs extending through the cooling jacket additionally comprising a second plurality of ribs extending generally horizontally within the plurality of horizontal passages.

A marine engine comprising an engine body defining at least one combustion chamber therein, the engine body including a cylinder head portion having a plurality of intake valves and a plurality of exhaust valves permitting selective communication with the combustion chamber, the cylinder head portion supporting a cam shaft configured to actuate the intake and exhaust valves, a lubrication system arranged to supply lubrication oil to a portion of the engine body and comprising a reservoir at least partially defining a space therein for holding lubrication oil, the reservoir including a cooling jacket in thermal communication with the space within the reservoir, an inlet and an outlet in fluid communication with the cooling jacket, a cooling system arranged to supply a flow of cooling fluid to the cooling jacket through the inlet and receive cooling fluid from the outlet, the cooling jacket including a plurality of distinct horizontal passages and being in fluid communication with one another, the cooling jacket being arranged such that the flow of cooling fluid passes in series through at least a portion of the horizontal passages, wherein the plurality of horizontal passages are at least partially defined by a first plurality of ribs extending from the outer surface of the reservoir, additionally comprising a second plurality of ribs extending generally horizontally within the plurality of horizontal passages.