Abstract: A heat exchanger is provided for a pressurized, closed cooling system for a marine propulsion engine. The heat exchanger includes a closed spiral passageway means for the fresh cooling water drawn from the lake or other water body. An outer housing encloses the spiral passageway and includes baffle means for directing of a coolant in a spiral path over the cooling passageway means within the housing. The coolant is thereby cooled by the circulating cold fresh water. An air discharge passageway means is provided in the center of the spiral path. The centrifugal forces associated with the spiral flow of the cooling coolant results in the water moving outwardly within the passageway while the air tends to collect within the center thereof where it is collected and discharged by the air passageway means for automatic separation and removal of the air.

Abstract: A heat exchanger is provided for a pressurized, closed cooling system for a marine propulsion engine. The heat exchanger includes a closed spiral passageway means for the fresh cooling water drawn from the lake or other water body. An outer housing encloses the spiral passageway and includes baffle means for directing of a coolant in a spiral path over the cooling passageway means within the housing. The coolant is thereby cooled by the circulating cold fresh water. An air discharge passageway means is provided in the center of the spiral path. The centrifugal forces associated with the spiral flow of the cooling coolant results in the water moving outwardly within the passageway while the air tends to collect within the center thereof where it is collected and discharged by the air passageway means for automatic separation and removal of the air.

Abstract: A centrifugal water cooling pump unit mounted to the front cover of an internal combustion engine and is connected directly to the camshaft. The pump unit includes a special intake chamber overlying an impeller having straight radial blades with inner ends spaced from the axis of rotation. The intake chamber is formed with a spiral discharge passageway to direct the water spirally about the impeller axis of the impeller, with the water introduced into the impeller adjacent the radially inner ends of the radial blades. A pair of shaft seals are provided in the front cover with a telltale opening therebetween to indicate leakage from the water pump. The impeller is formed of plastic to the end of the pump shaft by a clamping nut. A bell-shaped washer is interposed between the impeller and nut to limit the pressure made on the plastic impeller.