A 2-stroke ship engine completes a power cycle in two piston strokes, combining intake, compression, power, and exhaust. Key parts include the cylinder, piston, crankshaft, connecting rod, scavenging ports, and exhaust valve. It is known for high power-to-weight ratio and simplicity but requires efficient scavenging for optimal performance.

Key specifications and technical properties of a 2-Stroke Ship Engine:

Engine Specifications:

- Size: Typically ranges from 300mm to over 2,000mm bore diameter

- Power Output: 1,000 kW to over 80,000 kW

- RPM: 60 to 250 RPM (low-speed engines)

- Fuel Grade: Heavy Fuel Oil (HFO) or Marine Diesel Oil (MDO)

- Lubrication: Cylinder oil viscosity SAE 50 or higher

- Cooling: Freshwater or seawater cooling systems

- Buoyancy: Not applicable (engine is fixed within ship structure)

Engine Parts & Materials:

- Cylinder Liner: Cast iron or alloy steel with chrome plating

- Piston: Aluminum alloy or forged steel with ring grooves

- Connecting Rod: Forged steel or high-tensile alloy

- Crankshaft: High-strength forged steel

- Turbocharger: Nickel-based alloys for high-temperature resistance

- Exhaust Valve: Heat-resistant steel (e.g., Nimonic 80A)

- Bearings: White metal (Babbitt) or bronze alloys

- Gaskets & Seals: Graphite, PTFE, or elastomeric materials

Lubrication & Fluids:

- Cylinder Oil Viscosity: SAE 50 (BN 40-70 for HFO)

- System Oil Viscosity: SAE 30 or SAE 40 (BN 10-20)

- Cooling Water: Treated freshwater with corrosion inhibitors

- Fuel Viscosity: 180-700 cSt (preheated for combustion)