Yanmar 6LY400 Inboard Marine Propulsion Engine

Description

Need heavy continuous commercial shaft power? Select Yanmar 6LY400 Inboard Propulsion Engine packages, designed to power commercial fishing vessels, passenger catamarans, and offshore patrol boats up to 55 feet. Displacing 5.8 liters across six inline cylinders, this turbocharged and aftercooled block generates 400 horsepower at 3,300 RPM. Common-rail electronic fuel injection ensures quiet combustion, low smoke emissions, and smooth torque delivery.

High-tensile gray cast iron forms the monolithic cylinder block, equipped with induction-hardened parent cylinder walls that resist scuffing under boost. The fresh water cooling system integrates an aluminum heat exchanger housing with a cupronickel tube bundle, charge air cooler, and bronze sea water pump. Dry weight without transmission is 1,356 lbs, supported by a 20-quart oil pan, SAE 3 housing, and 0.5-inch fuel line connections.

Key Features of Yanmar 6LY400

Shipyards buy Yanmar 6LY400 inboard engine packages to power heavy displacement cruisers and commercial work vessels requiring continuous shaft power. The six-cylinder electronic common-rail configuration delivers massive low-end torque, allowing vessels to swing large diameter wheels with high efficiency.

• 400 horsepower continuous rating drives displacement hulls through strong tidal river currents.
• Denso common-rail electronic fuel injection operates at 2,000 bar to eliminate diesel exhaust smoke.
• Inline six-cylinder reciprocating balance suppresses harmonic vibration across all speeds.
• Charge air cooler enhances combustion density to optimize thermal efficiency across cruising speeds.
• Cast iron block architecture provides structural strength for continuous commercial duty cycles.
• Yanmar 6LY400 commercial stamina provides dependable propulsion in open ocean chop.
• Heavy-duty vibration isolators absorb engine harmonics to protect boat stringer beds.
• Electronic Vessel Control integrates helm throttle, gear shifting, and digital engine diagnostics.

Combustion Dynamics Thermal Capacities

Dual thermostats regulate internal coolant temperatures between 174°F and 188°F under continuous commercial operations. The six-cylinder block develops 760 lb-ft of torque at 2,000 RPM, giving vessels substantial wheel grip for towing and docking. Rated under continuous commercial marine duty, heat rejection transfers 245 kW into raw sea water circuits. Specific fuel consumption averages 202 g/kWh, burning about 7.15 gallons per hour at standard continuous commercial cruise speeds under loaded displacement conditions.

Exhaust Integration Bay Clearances

A water-cooled exhaust riser connects to 4.5-inch wet exhaust hose, meeting ABYC P-1 and USCG Title 46 commercial standards. Mounting brackets adjust across 26-inch to 30-inch stringer centers, preserving 3.0 inches of clearance below the oil pan. Flexible elastomer mounts absorb vibration from the hull.

Service Schedules Application Constraints

Electronic CAN-bus control levers connect straight to the engine control unit for instantaneous transmission engagement. Operators inspect raw water strainers, check oil levels, and monitor belt tension before getting underway. This engine package is not engineered for offshore racing hydroplanes, surface drives, or raw water cooled bilges without fresh water heat exchangers.

• Inspect sea water intake strainer before each shift.
• Inspect and clean heat exchanger zincs every 150 hours.
• Change engine lube oil, gear oil, and filters every 250 hours.

Warranty Terms Package Manifest

Commercial fleet buyers receive 2-Year or 2,500-Hour limited warranty protection on base castings and mechanical components. The shipping crate contains the bobtail engine package, vibration isolators, digital instrument cluster, five-meter extension wiring harness, oil extraction pump, and a complete technical service manual.