The 4.5L four-cylinder engine for boats is offered as either a propulsion or gen drive engine in either keel cooled or heat exchanger configurations. The engines are either turbocharged, non-aftercooled or turbocharged with boat jacket water aftercooling. The propulsion engines feature constant power to 400 rpm below rated speed, making these engines an excellent choice for launches, work marine boats, marine trawler boat yachts, and patrol craft.