Details
Cummins NTA855-M350 Marine Propulsion Engine (350 HP Continuous)
The Cummins NTA855-M350 represents a benchmark in commercial maritime power. Engineered as a 14-liter, inline 6-cylinder marine diesel engine, it delivers a continuous duty rating of 350 HP (261 kW) at a steady 1800 RPM. Manufactured by Chongqing Cummins Engine Co., Ltd. (CCEC), this specific propulsion package is built exclusively to handle the grueling hydrodynamic demands of commercial workboats operating around the clock.
As a dedicated marine power pack supplier, HekoPower provides the complete NTA855-M350 engine assembly, ensuring every unit meets rigorous CCS and IMO Tier II environmental standards. Our focus goes beyond simply shipping hardware. We supply comprehensive propulsion systems, managing everything from exact propeller shaft matching to specialized cooling configurations for global vessel repower projects.
Tech Specs of NTA855-M350
General Engine Data
General Engine Data
Engine Model: Cummins NTA855-M350
Type: 6 Cylinders in Line
Displacement: 14 L
Bore * Stroke: 140 * 152
Net Weight (with flywheel & alternator): 1430 Kg
Overall Dimension: 1809mm*881mm*1598mm
Engine Configuration No.: D0903348MX02
Key Performance Data
Rated Power: 261 kW/350HP
Rated Speed: 1800 rpm
Low Idle Speed: 575-675 rpm
High Idle Speed: 1962-2106 rpm
Rating Type: Continuous Running Power
Fuel Consumption (Running Speed): ≤ 220 g/kW.hr
Max Torque/Speed: 1385 N.m @ 1500 rpm
More Technical Data
Certification: CCS/IMO Certificates
Governor Type: Mechanical Control
Aspiration: Turbocharged/Aftercooled
Compression Radio: 14.5:1
Fuel System: Cummins Pressure Time (PT Pump)
Starting System: Electrical Start (24V/100AMP)
Lowest Starting Temp Without auxiliary system: -12℃
Cooling Method: Sea water pump, Heat exchanger, Water cooled
Technical Comparisons Within the 14-Liter Platform
Selecting the correct power node is the first step in a successful maritime build or repower. Navigating the different ratings within the same engine family can be confusing for shipyard managers. This series mainly includes the NTA855-M200, NTA855-M300, NTA855-M350, and NTA855-M400 models. While they share the same fundamental 14L cast-iron block, their internal thermal dynamics and intended duty cycles differ radically.
Stepping up from the lower-rated models, the NTA855-M350 is distinctly calibrated for heavy continuous duty. The M300 produces reliable power, but often lacks the reserve torque required for dragging heavy nets or towing loaded barges against strong river currents. Conversely, while the NTA855-M400 offers a higher top-end horsepower output, it is classified as an intermittent duty engine. The M400 is not designed to run at full throttle continuously without risking thermal overload.
The M350 rating strikes the exact mechanical balance. It allows commercial captains to leave the throttle wide open at 1800 RPM continuously, generating maximum thrust without exceeding the safe thermal limits of the exhaust valves or the turbocharged aftercooled system. Furthermore, reviewing the Cummins NTA855-M350 fuel consumption curve at 1800 RPM reveals a highly efficient burn rate compared to a de-rated M400 operating at the same speed.
Real Application Scenarios
The NTA855-M350 continuous duty marine engine thrives in high-drag, low-speed environments. In the commercial fishing sector, 350hp commercial fishing vessel marine diesel engines must sustain massive loads. When a trawler deploys its nets, the hydrodynamic drag effectively acts as an anchor. The NTA855-M350 generates a peak torque of 1385 Nm at a low 1500 RPM. This low-end rotational force ensures the vessel maintains its trawling speed without the engine lugging or stalling in heavy swells.
For inland waterways, this model is a premier engine for tugboats and commercial workboats. Pushing heavy, unpowered cargo barges upriver requires uninterrupted thrust. The NTA855-M350 provides the structural rigidity and continuous horsepower necessary for these grueling, multi-day transits.
Additionally, HekoPower frequently supplies this original Cummins NTA855-M350 engine for vessel repower projects. Because it retains the classic 14L external footprint, engine dimensions, and dry weight, shipyard engineers can execute a replacement marine propulsion engine project without undertaking a costly redesign of the vessel's internal engine beds or structural stringers.
Marine Gearbox Matching and Cooling Configurations
A marine engine cannot perform effectively without precise transmission integration. NTA855-M350 gearbox matching is a critical service provided by HekoPower. Given the 1385 Nm torque output at 1500 RPM, we typically match this engine with heavy-duty reduction gearboxes. A marine engine matching gearbox ratio of 3:1 to 4.5:1 is generally ideal for displacement hulls, allowing the engine to spin a large-diameter propeller slowly for maximum bollard pull.
Thermal management is equally critical to the NTA855-M350 marine engine installation. We offer two distinct cooling setups based on the vessel's operating environment. The heat exchanger sea water cooling system is the most common. It includes an integrated cupronickel heat exchanger and an engine-driven seawater pump. This setup is highly efficient for vessels operating in clean, deep ocean waters.
For vessels operating in muddy rivers, shallow coastal estuaries, or ice-laden waters, HekoPower recommends a keel cooling configuration. By utilizing an external cooler mounted on the hull, the system entirely eliminates the seawater pump and internal raw water circuits. This prevents mud, debris, or slush ice from clogging the engine cooling system, significantly reducing maintenance downtime for river-based commercial workboats.
Maintenance and Replacement Tips
Keeping the NTA855-M350 complete marine engine assembly operating at peak efficiency requires strict adherence to mechanical maintenance intervals. The PT pump marine diesel engine requires clean fuel to lubricate its internal gear pump. Operators must regularly drain the primary fuel-water separators and replace the fuel filters to prevent scoring the mechanical injectors.
Valve lash and injector timing should be verified every 1,500 operating hours. Because the PT fuel system relies on precise camshaft actuation to pressurize the fuel inside the injector cup, incorrect overhead adjustments will immediately degrade the engine's performance curve and increase fuel consumption. Furthermore, for engines equipped with heat exchangers, the sacrificial zinc anodes must be inspected monthly and replaced when they reach fifty percent depletion to prevent galvanic corrosion from destroying the internal cooling tubes.
Common Misconceptions in Marine Operations
A pervasive misconception in the maritime industry is that idling a heavy-duty engine or running it at very low RPMs will extend its lifespan and save fuel. For the NTA855-M350, prolonged operation below 1200 RPM under light loads is highly detrimental. It leads to a condition known as wet stacking. The cylinders do not generate enough heat to fully expand the piston rings or completely burn the injected diesel. This results in unburnt fuel washing the lubricating oil off the cylinder walls and thick carbon soot accumulating on the turbocharger turbine blades.
Another common misunderstanding involves parts interchangeability. Operators often assume that all 14L marine engine dimensions and weights dictate identical internal parts. While the blocks are similar, a genuine CCEC NTA855-M350 engine utilizes specific high-flow injector nozzles, targeted piston cooling nozzles, and a precisely calibrated turbocharger designed expressly for the 350HP continuous rating. Using standard automotive or generic replacement parts will cause severe thermal imbalances.
Chongqing Cummins NTA855 Marine Power Family
Selecting the right engine model requires matching your hull's displacement, desired cruise speed, and duty cycle requirements. Cummins N855-M Series (N855 Marine Engine), marine propulsion engines for commercial and recreational applications, original products from Chongqing Cummins Engine Plant(CCEC). This series mainly includes NTA855-M350, NTA855-M400, NTA855-M450, NTA855-M200, NTA855-M220, NTA855-M240, NTA855-M250, NTA855-M270, NTA855-M300. All engines complete with sea water pump, heat exchanger, CCS/IMO certificates.
Frequently Asked Questions (FAQ)
What is the expected lead time for a wholesale engine order?
Standard lead time for a newly assembled, original NTA855-M350 marine diesel engine supplier order from HekoPower is typically 15 to 25 days. Complex orders requiring custom gearbox packages, specialized power pack skids, or specific classification society witness testing may require an additional week for final sea-trial simulation.
Does the engine price include the marine gearbox and control panels?
The baseline NTA855-M350 marine propulsion engine price covers the bare engine assembly, standard heat exchanger cooling loop, and standard instrumentation. Gearbox packages, flexible couplings, custom propeller shaft matching, and advanced bridge control panels are calculated based on the specific vessel's architectural requirements.
Is this engine compliant with international shipping regulations?
Yes. The CCEC NTA855-M350 engine assembly with CCS IMO certification is fully compliant with IMO Tier II emissions standards. HekoPower works directly with maritime classification societies to ensure all exported engines are delivered with the proper documentation required by your local port authority and maritime insurance providers.
