Engine Cooling Systems Explained Boattest

Engine Cooling Systems Explained Boattest Most newer marine engines use an enclosed cooling system. this means that there is a small tank on the top of the engine that uses a combination of fresh water and coolant. this fresh water is circulated through the engine and through a heat exchanger. the fresh water, in this system, absorbs the heat of the engine. “the cooling system is quite simple,” said mike nimmer, mercury marine’s product service manager. “powered by an impeller in a water pump, raw water—whether it is salt, brackish, or fresh—comes in through the lower unit (in an outboard or sterndrive), is forced around the powerhead and then leaves the engine via the exhaust.

Boat Engine Cooling Systems Explained The pump sends cooling water out of the top of the housing through a long brass tube, typically about a half inch in diameter, up to the engine’s powerhead where it circulates through the system’s cooling passages and thermostats. salt, sand, mud, sticks, and other debris take their toll on the pump impeller, housing, and related parts. The water flows through the engine and directly out the exhaust. this cooler water absorbs heat from the engine to help keep it cool. most newer marine engines use an enclosed cooling system. this means that there is a small tank on the top of the engine that uses a combination of fresh water and coolant. this fresh water is circulated through. A keel cooling system uses externally mounted tubes and pipes on the outer hull of the boat, below the water line. this system works a bit like a radiator. hot water or coolant from the engine is pumped through the pipes which are underwater. the cooling water in which the boat is immersed absorbs the heat as it circulates through the pipes and. Today almost all new marine engines use the closed cooling system design. these systems are pressurized, just like your car or truck. by increasing the pressure inside the closed part of the system, the boiling point of the coolant is enhanced. for every pound of pressure added, approximately 3° f can be added to your engine’s operating.