L6125A 325 / 425 / 460 / 500

Product catalog summary

Engine Specifications
The L6125A marine diesel engine is built on a robust Komatsu engine block for heavy-duty applications. It includes a thermostatically controlled stainless steel lube oil cooler, nodular cast iron pistons, and replaceable wet cylinder liners. The engine is turbocharged and aftercooled, with a displacement of 674 CID (11 liters) and a bore x stroke of 4.92 x 5.91 inches (125 x 150 mm). Power ratings are 325 hp at 2100 rpm for continuous duty, 425 hp at 2300 rpm for medium duty, and 500 hp at 2300 rpm for high output.

Performance and Efficiency
Designed for high performance with low life-cycle costs, the engine offers a specific fuel consumption rate as low as 0.355 lbs/hp/hr. It provides high torque and a favorable power-to-weight ratio, ensuring efficient fuel use and long engine life. The design minimizes noise and vibration for enhanced operational comfort.

Cooling and Lubrication Systems
The engine features a jacket water cooled turbocharger and exhaust manifold, with a cupro-nickel heat exchanger for efficient temperature control. The lubrication system includes a gear-type high capacity oil pump and a stainless steel, plate-type oil cooler integrated into the block to eliminate hoses.

Maintenance and Durability
Maintenance is simplified with all service points on one side, and the inline design allows easy access. Durable materials like nodular cast iron for pistons and a one-piece forged steel crankshaft enhance longevity. The engine is painted with white polyurethane for visibility and easy cleaning.

Electrical and Additional Features
The engine includes a 12-volt marine grade electrical system with options for higher output alternators. It is equipped with a standard panel featuring essential gauges and alarms. Optional accessories include a front PTO with electric clutch, additional alternators, and various exhaust configurations.

Warranty and Testing
The L6125A comes with a three-year limited warranty, with no hourly limit in the first year. Each engine undergoes rigorous dyno testing post-marinization to ensure reliability and performance.

Air and Exhaust

Engine Air Consumption: 652 cfm (18 m³/min) to 1050 cfm (30 m³/min).
Minimum Engine Room Vent Area: 173 sq in (0.11 m²) to 279 sq in (0.18 m²).
Exhaust Gas Flow: 1865 cfm (53 m³/min) to 2811 cfm (80 m³/min).
Exhaust Gas Temperature: 840°F (448°C) to 975°F (528°C).
Maximum Exhaust Back Pressure: 30 in (762 mm) H₂O.
Suggested Exhaust Diameter: Dry: 5-6 in (125-150 mm), Wet: 6-8 in (150-203 mm).

Fuel and Oil

Minimum Fuel Suction Line: 0.5 in (12 mm).
Minimum Fuel Return Line: 0.375 in (10 mm).
Maximum Fuel Pump Head: 39 in (1 m).
Crankcase Oil Capacity: 34 US qts (32 liters).

Other Data

Engine Rotation: Counter-Clockwise (facing flywheel).
Flywheel Housing Size: Standard SAE 2, 11.5” (Optional SAE 1, 14”).
Optional Front PTO Size: SAE # - 4-8”, 4-10” or 3-11.5”.
Maximum Operating Angle: 35° for less than 2 minutes in any direction.
Maximum Installed Operating Angle: 10° rear down - 0° front down.
Keel Cooled Weight: 2400 lbs (1090 kg) without gear.
Heat Exchanger Weight: 2450 lbs (1115 kg) without gear.

Catalog excerpts

? Jacket water cooled, cast iron exhaust manifold. Two pass coolant fl ow for even temperature control. ? Jacket water cooled turbocharger turbine for safety. ? Individual, four valve cylinder heads. Valves can be adjusted without disturbing fuel lines. ? Cupro-nickel heat exchanger. Removable end covers and tube stack make cleaning easy. ? Large, cast expansiontank. Easy coolantfi ll. No welds to break. ? Easily accessible raw water pump. ? 24 or 12 volt battery charging alternator. ? Beltguard protects operator. ? Crankshaft designed for an electric clutch PTO providing up to 1000 foot pounds of torque for hydraulic power. ҕ Thermostatically controlled stainless steel lube oil cooler built into block. No hoses. ? Sparkling white IMRON > polyurethane paint for a tough fi nish.? Optional star- board oil dipstick. Optionalwet and dry exhaust elbows available. ? Reversible oil pan shown with sump in standard aft position. ? 12 or 24 volt starter motor. ? Cupro-nickel gear oil cooler for long oil life and better lubrication. >

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? Top and side oil fi lls. ? Jacket water aftercooler increases performance. Thermostatically controlled to avoid overcooling. ? Large air fi lter helps silence intake. ? Optional 8.9 HP accessory drive with pulley mounts here. ? Instrument panel wire harness plugs. ? Spin-on oilfi lter. ? Optional gear and engine oil change pump makes maintenance quick and clean. ? Spin-on fuelfi lter. > Service points are grouped on this side for ease of maintenance. ? Stainless steel and bronze raw water pump. ? Removable cupro-nickel heat exchanger element. ? Large, cast expansion tank. Easy coolant fi ll....

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Fuel System ? Direct injected for better fuel economy and fast starts. ? Inline Bosch-type injection pump is gear driven and force lubricated. High pressure for better fuel atomization.? Bosch-type rebuildable injectors are placed in the center of the cylinder for the most efficient fuel spray pattern and increased fuel economy.? Fuel system design is self-venting and minimizes lube oil dilution. ? Large spin-on fuel filter element. ? Positive displacement mechanical fuel transfer pump is cam driven. Air System ? Large capacity, plate-type aftercooler uses jacket-water, not corrosive sea- water,...

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L6125A 325 / 425 / 460 / 500

L6125A 325 / 425 / 460 / 500

Catalog excerpts

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