The Yanmar 3JH40 Marine Diesel Engine is a state-of-the-art, 3-cylinder, 4-stroke, common rail (CR) direct injection engine designed to deliver 40hp at 3000 rpm. It is the world’s smallest CR inboard marine diesel engine, making it a game-changer for sailors and boaters who need high performance combined with compact design and fuel efficiency. The 3JH40 is ideal for sailboats, yachts, and light-duty commercial vessels, offering smooth operation, low emissions, and quiet performance.
This engine uses common rail direct injection technology, which improves fuel efficiency and reduces emissions while providing exceptional torque and power delivery. The freshwater cooling system ensures that the engine operates at optimal temperatures, while reducing corrosion for extended engine life. It complies with strict global emission standards such as EPA Tier 3 and EU RCD Stage II.
Technical Specifications:
- Engine Model: 3JH40
- Engine Type: 3-cylinder, 4-stroke, vertical water-cooled diesel engine
- Displacement: 1.642 litres (1642 cc)
- Bore x Stroke: 84 mm x 90 mm
- Power Output: 40hp (29.4 kW) at 3000 rpm
- Compression Ratio: 18.9:1
- Fuel System: Common rail direct injection (CR)
- Cooling System: Freshwater cooling with heat exchanger
- Alternator Output: 12V – 125A
- Lubrication System: Forced lubrication by gear pump
- Oil Capacity: 5.1 litres
- Starting System: Electric start
- Direction of Rotation: Counterclockwise (viewed from flywheel)
- Weight: 192 kg (without gearbox)
- Gearbox Options: KM35A, KM4A2, or ZF gearbox
- Reduction Ratios: 2.14:1, 2.61:1 (KM35A) or 2.20:1, 3.12:1 (KM4A2)
- Exhaust System: Water-cooled, with wet exhaust manifold
- Fuel Consumption: Approx. 6.7 litres/hour at full load
- Emission Compliance: EPA Tier 3, EU RCD Stage II
Key Features:
- Common Rail Direct Injection (CR): Enhances fuel efficiency, reduces emissions, and provides superior power output.
- Compact Design: Ideal for sailboats and yachts with limited engine compartment space.
- Low Emissions: Meets stringent EPA Tier 3 and EU RCD Stage II emission standards.
- Freshwater Cooling System: Helps prevent internal corrosion and maintains consistent engine temperatures.
- Fuel-Efficient: Lower fuel consumption makes it an environmentally-friendly choice.
- Smooth and Quiet Operation: Low vibration and noise levels enhance the comfort of the onboard experience.
Yanmar is a world leader in marine diesel engines, known for their durability, fuel efficiency, and advanced technology. The Yanmar 3JH40 is the world’s smallest common rail diesel engine, offering superior performance and compliance with global emission standards.
Yanmar offer three main transmission options for the 3JH40. The Kanzaki KM35P/A is a mechanical marine gearbox with hydraulic clutch control, ideal for inboard configurations. The SD60 SailDrive offers a smooth and efficient drive system, reducing vibration and enhancing performance for sailboats, especially when paired with Yanmar’s 3JH series engines. Lastly, bobtail engines are complete engine replacements for both stern drive and inboard applications, including essential systems such as fuel, electrical, cooling, exhaust, and engine mounts.
