Description
Mitsubishi S6A3-MPTK
The Mitsubishi S6A3-MPTK is a robust marine diesel engine designed and manufactured by Mitsubishi Heavy Industries in Japan for demanding marine propulsion applications. It belongs to Mitsubishi line of medium-speed, turbocharged, water-cooled diesel engines and is engineered for reliable, continuous operation in vessels such as ferries, fishing boats, workboats, tugboats, and other commercial vessels requiring efficient propulsion power.
Core Design & Construction
Engine Type: 4-stroke, water-cooled, direct-injection diesel engine with turbocharger and inter-cooler (charge air cooled by seawater).
Cylinders: Six-cylinder inline layout optimized for balanced performance and smooth operation.
Displacement: 18.56 liters total (bore 150 mm × stroke 175 mm).
Compression Ratio: 14.5 : 1, giving strong combustion and efficient fuel utilization.
Construction: Heavy-duty cast iron block and cylinder heads with individual access for easier maintenance.
Performance & Ratings
The S6A3-MPTK offers a range of power outputs depending on rating and engine speed:
Output Range: From approximately 368 kW (≈493 hp) up to 445 kW (≈597 hp) for propulsion use.
Engine Speeds: Typically between 1840 rpm and 1900 rpm for rated propulsion outputs.
Emissions Levels: Can be configured for IMO Tier II or lower emission specifications where required.
Fuel System: Mechanical direct fuel injection optimized for stable combustion and fuel economy.
Cooling & Auxiliary Systems
Cooling Method: Separate high- and low-temperature cooling circuits with charge air cooler directly cooled by seawater (intercooler).
Heat Exchanger & Sea Water Pump Package: Mitsubishi offers complete packaged cooling solutions that streamline installation and maintenance.
Dimensions & Weight
Dry Weight: Around 1900 kg – 2100 kg depending on configuration and accessories.
Overall Size: Roughly 2090 mm × 1019 mm × 1370 mm (L × W × H) for the standard engine package.
Operational Advantages
Reliable & Durable: Engineered for continuous marine duty with proven Mitsubishi technology that emphasizes long service life and operational reliability.
Fuel Efficient: Turbocharged and air-cooled design delivers high thermal efficiency and lower specific fuel consumption.
Ease of Installation & Maintenance: Compact footprint, integrated sea water pump and heat exchanger package, plus easy access to major components for servicing.
Typical Applications
Marine propulsion on ferries, fishing vessels, workboats, and tugboats
Auxiliary power generation or hybrid propulsion systems in marine installations.
General Engine Data
Engine model: Mitsubishi S6A3-MPTK
Type: 4-stroke, water-cooled diesel engine with direct fuel-injection, turbocharger, and charge-air cooler
Cylinders: 6-in-line
Total displacement: 18.56 liters
Bore × Stroke: 150 mm × 175 mm
Compression ratio: 14.5 : 1
Flywheel & housing: SAE 14 / SAE 10 (varies by setup)
Dry weight: ~2,030 – 2,100 kg (depending on configuration)
Dimensions (approx.): 2189 mm (L) × 1127 mm (W) × 1421 mm (H)
Cooling & Auxiliary Systems
Cooling type: Separate high- and low-temperature coolant circuits
Charge-air cooler: Air cooler (intercooler) cooled with seawater
Heat exchanger & seawater pump: Included in typical marine package
Designed for continuous marine operation with efficient heat management
Fuel & Combustion
Fuel system: Mechanical direct fuel injection
Turbocharging: Single turbocharger for improved efficiency and power delivery
Combustion: Stable, efficient combustion with optimized injection timing
Operational Characteristics
Built for marine propulsion use — stable power delivery and durability
Suitable for vessels such as ferries, tugboats, workboats, and fishing boats
Designed for high reliability and long service intervals
General Features
Robust [heavy-duty] cast iron engine block and head
Water-cooled cylinder liners
Balanced inline-6 configuration for smoother operation
Options for emission compliance depending on region and application
