Yanmar 6LY440 440HP Inboard Diesel Engine
High-Performance Marine Diesel Power with Advanced Reliability
The Yanmar 6LY440 440HP Inboard Diesel Engine is a premium high-output marine diesel engine engineered to deliver exceptional acceleration, powerful torque, outstanding fuel efficiency, and long-term durability for demanding recreational and commercial marine applications. Designed with advanced common rail fuel injection technology and turbocharged performance, this 6-cylinder inboard diesel engine produces 440 horsepower while maintaining smooth operation, low emissions, and dependable reliability in harsh marine environments.
Built for sport fishing boats, luxury cruisers, offshore vessels, commercial craft, and high-performance marine applications, the Yanmar 6LY440 combines compact engineering, lightweight construction, and advanced electronic controls to provide responsive handling and superior cruising performance. Its excellent power-to-weight ratio and proven Yanmar marine technology make it an ideal solution for boat owners seeking reliable high-performance diesel propulsion.
The Yanmar 6LY440 is powered by a robust 5.8-liter inline 6-cylinder diesel platform designed for continuous marine operation. Delivering 440 horsepower at 3300 RPM, the engine produces strong low-end torque and rapid throttle response, allowing vessels to achieve faster planing speeds, improved load handling, and efficient high-speed cruising performance.
The engine features an advanced turbocharged and intercooled aspiration system that maximizes airflow efficiency and combustion performance. The turbocharger delivers increased air pressure to the combustion chamber for stronger power output, while the intercooler reduces intake air temperature to improve combustion density, fuel efficiency, and overall engine reliability during extended operation.
Equipped with a modern electronically controlled common rail direct injection system, the 6LY440 delivers precise high-pressure fuel delivery for cleaner combustion and optimized engine performance. This advanced fuel management technology improves fuel atomization, reduces fuel consumption, minimizes exhaust emissions, and provides smoother and quieter engine operation compared to traditional diesel injection systems.
The engine incorporates Yanmar’s electronic vessel control technology for accurate throttle response, smooth gear engagement, and integrated engine diagnostics. The advanced electronic management system continuously monitors engine performance and operational conditions to optimize efficiency and improve reliability during demanding marine use.
A freshwater cooling system with a highly efficient heat exchanger protects internal engine components from corrosion while maintaining stable operating temperatures in both freshwater and saltwater environments. Heavy-duty marine-grade materials and corrosion-resistant components ensure long-lasting durability even under continuous offshore operation.
The Yanmar 6LY440 is engineered for reduced vibration and quieter performance, enhancing onboard comfort for passengers and crew. Precision-balanced internal components, advanced combustion control, and flexible engine mounting systems help minimize engine noise and vibration levels during cruising and high-speed operation.
Its compact engine dimensions and relatively lightweight design allow easier installation in a wide range of vessel configurations while maintaining exceptional performance capabilities. The engine is suitable for both new vessel construction and marine repower projects where space efficiency and high horsepower are essential.
The high-output alternator system provides reliable charging power for navigation systems, communication equipment, lighting, refrigeration, battery banks, and other onboard electrical accessories. This makes the engine highly suitable for modern vessels equipped with advanced marine electronics and higher electrical demands.
Yanmar designed the 6LY440 to comply with major international marine emissions and environmental regulations, including EPA Tier 3 and EU RCD standards. The engine delivers environmentally responsible performance while maintaining the strong power and fuel efficiency expected from a premium marine diesel engine.
Renowned for its durability, fuel economy, and dependable operation, the Yanmar 6LY440 440HP Inboard Diesel Engine is an excellent propulsion solution for serious boaters and marine professionals seeking powerful diesel performance, advanced technology, and long-term marine reliability.
Key Features
- 440HP high-performance marine diesel engine
- 5.8L inline 6-cylinder diesel platform
- Turbocharged and intercooled aspiration system
- Electronically controlled common rail direct injection
- Strong low-end torque and fast acceleration
- Advanced electronic vessel control system
- Excellent fuel efficiency and long-range cruising capability
- Freshwater cooling with heat exchanger protection
- Smooth, quiet, and low-vibration operation
- Compact and lightweight engine construction
- Corrosion-resistant marine-grade components
- High-output alternator for onboard electronics
- EPA Tier 3 and RCD compliant
- Designed for recreational and commercial marine use
- Proven Yanmar durability and reliability
Technical Specifications
| Specification |
Details |
| Engine Model |
Yanmar 6LY440 |
| Engine Type |
Inline 6-Cylinder 4-Stroke Marine Diesel |
| Horsepower |
440 HP (324 kW) |
| Rated RPM |
3300 RPM |
| Displacement |
5.8 Liters |
| Number of Cylinders |
6 Cylinders |
| Fuel System |
Common Rail Direct Injection |
| Aspiration |
Turbocharged & Intercooled |
| Cooling System |
Freshwater Cooling with Heat Exchanger |
| Engine Controls |
Electronic |
| Starting System |
Electric Start |
| Fuel Type |
Marine Diesel |
| Alternator Output |
High-Output Marine Alternator |
| Dry Weight |
Approx. 535 kg |
| Emissions Compliance |
EPA Tier 3 / EU RCD |
| Application |
Inboard Marine Diesel |
Applications
- Offshore sport fishing boats
- Luxury cruising yachts
- High-performance recreational vessels
- Commercial marine boats
- Coastal and offshore cruising applications
- Marine repower projects
- High-speed inboard diesel installations
Advantages
- Outstanding power-to-weight ratio
- Strong acceleration and responsive throttle performance
- Excellent fuel economy for extended cruising
- Advanced common rail fuel injection technology
- Reduced emissions and cleaner combustion
- Smooth and quiet diesel engine operation
- Reliable performance in demanding marine conditions
- Compact dimensions for easier installation
- Long service life with low maintenance requirements
- Proven Yanmar marine engineering quality
The Yanmar 6LY440 440HP Inboard Diesel Engine combines powerful diesel performance, advanced fuel management technology, compact marine engineering, and exceptional reliability to deliver a premium propulsion solution for modern recreational and commercial marine applications.
