Description
Mitsubishi S12A2-MPTA 634 kW 1940 RPM
The Mitsubishi S12A2 MPTA is a high-output heavy-duty marine diesel engine engineered for demanding propulsion applications on larger commercial vessels. With a rated output of 634 kW (approximately 850 HP at 1940 RPM this powerful V12 engine delivers exceptional performance, robust torque, and long-lasting reliability that operators depend on in challenging marine environments.
Designed and manufactured by Mitsubishi Heavy Industries, the S12A2-MPTA combines advanced diesel technology with rugged construction. Its turbocharged and aftercooled configuration ensures efficient air induction and combustion, resulting in improved power delivery, fuel economy, and thermal performance. The engine’s precision fuel injection system optimizes combustion timing and fuel atomization, contributing to stable performance across a wide range of loads.
The 12-cylinder inline arrangement provides excellent mechanical balance and high torque output, making it well-suited for propulsion systems where sustained power and smooth operation are essential. Mitsubishi robust cooling system maintains optimal engine temperatures during continuous high-load operation, while the heavy-duty cast-iron block and reinforced internal components are built to withstand extended periods of service with minimal wear.
The S12A2-MPTA is designed for seamless integration with marine gearboxes, control systems, and auxiliary systems, allowing for flexible installation in a variety of vessel types, including tugboats, offshore support craft, coastal ferries, and large workboats. With a comprehensive global support network and widely available spare parts, the engine offers enduring performance and straightforward maintenance over its operational life.
Whether tasked with propulsion, heavy cruising, or continuous power delivery, the Mitsubishi S12A2-MPTA stands out as a powerful, efficient, and reliable solution for marine operators seeking high horsepower and durability in demanding environments.
Technical Specifications
General Engine Data
Engine Model: Mitsubishi S12A2 MPTA
Engine Type: 4-stroke, water-cooled, turbocharged diesel
Aspiration: Turbocharged with charge-air cooling
Cylinders: 12 inline
Displacement: ~33.93 liters
Bore × Stroke: ~150 mm × 160 mm
Compression Ratio: ~14.5 : 1
Fuel System: Direct fuel injection
Rated Speed: 1940 RPM
Rated Power Output: 634 kW (~850 HP) at 1940 RPM
Rotation: Normally counter-clockwise (viewed from flywheel end)
Mounting: Marine engine mounts
Performance
Continuous Rated Power: 634 kW at 1940 RPM
Torque: High torque output optimized for marine propulsion
Designed for sustained continuous duty at rated speed
Cooling & Lubrication
Cooling System: Engine coolant-to-sea/water heat exchanger system
Charge-Air Cooling: Intercooler (cooling after the turbocharger)
Lubrication: Full-flow oil filtration with large oil capacity for extended service intervals
Physical Dimensions & Weight
Approx. Dry Weight: 3,700 – 4,000 kg (varies with accessories and configuration)
Approx. Size: Around 2.6 m (L) × 1.6 m (W) × 1.6 m (H) (engine block only, varies by accessory)
Systems & Operation
Cooling Water Pumps: Belt-driven coolant and seawater pumps
Starter: 24 V electric starter
Equipment: Flexible accessory drive for alternators, pumps, and other auxiliary equipment
Heat Rejection: Optimized for continuous load marine use
Applications
Designed primarily as a marine propulsion engine for larger vessels such as:
Tugboats
Offshore support vessels
Coastal ferries
Workboats and supply vessels
Other commercial craft requiring robust, continuous power
Key Features
Heavy-duty cast iron construction for long service life
Turbocharged and aftercooled for enhanced performance and fuel efficiency
Strong torque characteristics ideal for marine propulsion
Designed for integration with marine transmissions, control systems, and auxiliary components
Widely supported globally with spare parts and service networks









