The Mercruiser 5.7 marine system is a General Motors cast iron marine engine coupled with a Mercury stern drive for propulsion. Compatible drives for the Mercruiser 5.7 are the Alpha One, Bravo One, Bravo Two and the Bravo Three dual propeller drive units.
The Mercruiser 5.7 has the Mercury Marine Thunderbolt high energy ignition system and high flow cylinder heads for increased horsepower and efficiency. It also incorporates a new water drain system to simplify winterization. The engine has a turn key starting system.
The Mercruiser 5.7 liter marine engine is offered in three different configurations. The standard 5.7 has a propshaft rating of 250 horsepower. The 5.7 EFI or electronic fuel-injected model produces 260 horsepower. The 350 Magnum MPI or Multi Port Fuel Injection engine is rated at 300 propshaft horsepower.
The Mercruiser 5.7 weighs 888 pounds dry. The engine is 13 inches in length, 22 inches high and 30 inches wide. It has 350 cubic inches of displacement and a bore and stroke of 4.00 x 3.48. Displacement is the combined measurement of the volume inside the cylinders that is displaced by the pistons. The compression ratio is 9.4:1.