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