How marine engine works?

The "engine" part of a marine engine is the same as any other kind of engine. The difference is the cooling system, and there are two kinds: raw water and enclosed.

Raw water systems are used on outboards and small pleasure boats with inboard engines. The engine's water pump sucks water out of the lake, runs it through the engine and puts it back in the lake. This works with a minimum of parts, until you get into boats that run in salt water. Would YOU want ocean water running through your engine? Neither would yachtsmen with expensive diesels.

The enclosed cooling system uses a heat exchanger. There's a tank on the boat with a radiator in it. The engine pumps coolant through the radiator just like it would the radiator on a car. A second pump pulls water out of the ocean and feeds it into the tank to cool the radiator. There's more maintenance in this system (you have to be sure saltwater scale isn't blocking the heat exchanger and you've got more water pumps to deal with) but it is more reliable than feeding raw water into the engine.

First answer by Jmowreader. Last edit by Jmowreader. Contributor trust: 792 [recommend contributor]. Question popularity: 1 [recommend question].