Modern ship engines are highly efficient, often using diesel or gas turbine technology to power vessels. Key engine parts include the cylinder block, pistons, crankshaft, turbochargers, and fuel injection systems. Advanced designs focus on reducing emissions and improving fuel economy while maintaining robust performance.

Modern ship engines typically range from 500 kW to 80,000 kW in power output. Common types include two-stroke and four-stroke diesel engines, with cylinder bores ranging from 200 mm to 960 mm. Engine parts are often made of high-grade steel, cast iron, or aluminum alloys, with components like pistons, crankshafts, and liners designed for durability.

Lubricating oils used in ship engines have viscosities ranging from SAE 30 to SAE 50, with some synthetic blends offering improved performance. Fuel grades include heavy fuel oil (HFO) with viscosities up to 700 cSt at 50°C and marine diesel oil (MDO) with lower viscosities. Buoyancy considerations are critical for engine placement, with weight distribution optimized for stability.

Cooling systems often use seawater or freshwater, with heat exchangers made of corrosion-resistant materials like titanium or cupronickel. Exhaust systems may include scrubbers to reduce emissions, compliant with IMO Tier III standards. Engine blocks and housings are designed to withstand high pressures and temperatures, often exceeding 300°C.