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