Details
Genuine Cummins 4BTA3.9-G2 Engine Wholesale (50kW G-Drive)
The Cummins 4BTA3.9-G2 is a turbocharged four-cylinder diesel engine developed for generator drive applications requiring stable 50Hz power output at 1500RPM. Manufactured by Dongfeng Cummins Engine Company (DCEC), this model is widely used in standby and prime power generator systems in industrial, telecom, commercial, and infrastructure projects.
Compared with smaller naturally aspirated generator engines, the 4BTA3.9-G2 provides improved torque response and better altitude adaptability due to its turbocharged air intake design. The compact inline-four structure also makes installation easier in generator enclosures where space is limited.
For customers replacing aging 50kW generator engines, the 4BTA3.9-G2 is often selected because of its balance between fuel economy, maintenance accessibility, and long-term spare parts availability.
The engine is commonly integrated into:
- Open-type diesel generator sets
- Silent canopy gensets
- Trailer-mounted power stations
- Emergency standby power systems
- Telecom tower backup generators
Unlike many low-cost alternatives in the market, genuine DCEC Cummins engines maintain stronger consistency in casting quality, fuel system calibration, and load acceptance performance.
Tech Specs of Cummins 4BTA3.9-G2
General Engine Data
Engine Model: Cummins 4BTA3.9-G2-50kw
Type: 4 Cylinders in Line, 4 Stroke Diesel
Displacement: 3.9 L
Bore * Stroke: 102 * 120
Net Weight: 350 Kg
Overall Dimension: 867mm*544mm*988mm
Key Performance Data
Rated Power/Standby Power(1500 rpm): 50 kW/67 HP, 55 kW/74 HP
Rated Power/Standby Power(1800 rpm): 60 kW/80 HP, 66 kW/88 HP
Rated Speed: 1500/1800 rpm
Low Idle Speed: 950-1050 rpm
Fuel Consumption @ Running: ≤ 230 g/kW.hr
Torque @ Rated/Standby Output: 318/350 N.m @ 1500 rpm
More Technical Data
Aspiration: Turbocharged/Afatercooled
Fuel System: BYC A Pump/RSV Governor
Electrical System (Starter Motor/Alternator): 12V/24V
Lowest Starting Temp Without auxiliary system: -12℃
Cooling Method: Water cooled
Engine Cooling Fluid Volume: 7.9 L
Governor Type: Electronic, Regulation ≤5%
Evaluating the Cummins 4BTA3.9-G2 Design
Selecting a mid-range industrial power unit requires an analysis of core fuel management systems and mechanical tolerances. The Cummins 3.9L turbocharged diesel engine delivers specialized performance across demanding industrial environments.
Fuel Injection Systems and Governor Settings
The basic engine block layout utilizes a mechanical injection architecture built for harsh operational environments. This configuration features a specialized high-pressure injection arrangement.
- Injection Pump Assembly: The engine uses a genuine BYC A-series inline fuel injection pump paired with a mechanical centrifugal governor.
- Governor Regulation Stability: The baseline BYC A pump governor settings for the Cummins 4BTA3.9-G2 maintain steady-state speed regulation within a narrow 3% to 5% droop margin. This standard prevents severe electrical frequency drops when matching load steps on 50Hz equipment.
- Contamination Resistance: Competitor sites often neglect how fuel system selection impacts regional operations. Unlike sensitive electronic common-rail fuel systems, the mechanical BYC A pump handles lower-grade or poorly filtered diesel fuel without suffering immediate plunger wear. This mechanical configuration lowers overall operational risks in remote regions.
Air Handling and Thermal Efficiency
The letter "A" in the 4BTA design designation highlights the inclusion of a dedicated charge-air cooling circuit. This feature provides a significant upgrade over basic turbocharged configurations.
- Aspiration Architecture: The engine uses a turbocharger and aftercooler design rather than traditional natural aspiration. The compressor side pushes dense air through a jacket-water cooled or air-to-air aftercooler matrix before the intake stroke.
- Volumetric Efficiency: Lowering the intake manifold air temperature increases total oxygen density during combustion. This structural cooling keeps peak thermal loads well within safe limits, helping the engine maintain its 50kW 50Hz Cummins 4BTA3.9-G2 prime power rating during long runs.
Comparison Between the 4BTA3.9-G2 and Other Cummins G-Drive Engines
4BTA3.9-G2 vs 4BT3.9-G2
Although both engines belong to the Cummins 3.9L family, the 4BTA3.9-G2 includes turbocharging, which improves power density and load response.
The naturally aspirated 4BT3.9-G2 may be suitable for lighter-duty applications, but the turbocharged 4BTA3.9-G2 performs better in environments requiring faster load acceptance or operation at higher altitudes.
4BTA3.9-G2 vs 6BT5.9-G Series
The 6BT5.9-G series offers higher power capacity and smoother six-cylinder operation, but it also increases fuel consumption and installation size.
For customers specifically targeting the 50kW range, the 4BTA3.9-G2 often provides a more economical solution without unnecessary oversizing.
This comparison section helps differentiate the page from competitors that only publish specification tables without discussing selection logic.
Real Application Scenarios for the 50kW Cummins Diesel Engine
This model operates across diverse commercial and field-level roles. Its structural footprints and fuel delivery maps match several common business operation models.
50Hz Telecom Infrastructure and Data Centers
Telecommunication networks require immediate power response if the primary electrical grid drops out. The Cummins engine for telecom backup power provides the exact starting reliability needed for critical infrastructure sites.
- Fast Transient Response: The complete Cummins standby power engine package transitions from a cold stop to a synchronized 1500RPM within 10 seconds of receiving a start signal.
- Load Absorption Capacity: The mechanical drive system absorbs high initial step loads from server cooling banks and transceiver towers without experiencing voltage drops.
- Wet-Stacking Mitigation: Backup generator sets often idle during weekly automated diagnostic routines. The optimized match between the turbocharger housing and the 3.9L displacement helps maintain proper internal cylinder heat, reducing the risk of unburnt fuel deposits forming in the exhaust system during low-load tests.
Prime Power for Construction and Industrial Sites
Off-grid project locations require a tough, standalone power plant. The Cummins 4BTA3.9-G2 for construction power station operations serves as the primary power source for tools, lighting fields, and crew quarters.
- Continuous Duty Cycles: The engine supports the Cummins 4BTA3.9-G2 prime power application profile by delivering a steady mechanical output of 50kW under varying loads for extended run times.
- Structural Material Selection: The cylinder block uses high-strength cast iron without dry liners. This solid construction limits physical distortion from block resonance and high engine vibrations.
- Torque Profiles: The 3.9-liter layout generates stable low-end torque. This allows the system to recover quickly when heavy electric motors or site equipment cycle on.
Maintenance and Replacement Guidelines for Field Technicians
Regular, structured maintenance preserves performance margins and prevents sudden component failure over years of service.
Drop-In Replacement Protocols for 50kW Generators
When swap-outs become necessary, using a genuine Cummins 4BTA3.9-G2 replacement engine for 50kw generator setups minimizes retrofitting time and structural adjustments.
- Mounting Interchangability: The standard SAE3 flywheel housing footprint and 11.5-inch clutch connection spaces align cleanly with older 4BT variations. This standard alignment prevents the need for modification of the generator's original steel base frame.
- Coupling Alignment Tolerances: Technicians must measure and verify the concentric alignment between the engine crankshaft flange and the single-bearing alternator face. Keep radial and axial runout deviations under 0.05mm to avoid bearing wear and severe shaft vibrations.
- Cooling System Integration: Verify that the existing radiator core can handle the extra heat rejected by the aftercooler lines. Reusing a radiator built for a non-aftercooled engine can trigger early high-temperature alarms during high-load operations.
Critical Service Windows and Wear Component Checks
Sticking to an exact service schedule keeps key components protected throughout the engine's operational life.
- Oil System Upkeep: Replace the engine lubricating oil and the full-flow spin-on oil filter element every 250 operational hours. Use standard 15W-40 weight oil to prevent friction wear across the valve mechanism.
- Fuel Filtration Upkeep: The BYC inline injection pump requires clean fuel. Drain and replace the primary fuel-water separator insert every 500 hours to stop water from pitting the injection tips.
- Mechanical Valve Train Settings: Inspect and reset mechanical valve clearances every 1,200 operating hours. Adjust the intake valves to 0.25mm and the exhaust valves to 0.51mm when the block is completely cold.
Commercial Procurement
HekoPower Cummins 4BTA3.9-G2 Lead Time and Shipping
Our logistics pipeline ensures fast delivery to reduce project delays for our international B2B clients.
- Inventory Control Strategy: HekoPower maintains ready-to-ship stock of the Cummins 4BTA3.9-G2 power pack assembly at our main regional export warehouses.
- Preservation and Packing: Technicians spray all bare metal surfaces with anti-corrosion oils before securing the unit onto heavy wooden transport bases. The entire assembly is sealed in industrial-grade moisture barriers to protect it from humid maritime shipping conditions.
- Port Logistics Timing: Standard transport from our warehouses to domestic departure ports takes 7 to 14 business days. We provide complete bills of lading, factory performance records, and country-of-origin certificates for smooth customs clearance.
Cummins 4BTA3.9-G2 Genuine Parts Warranty Terms
- Warranty Duration: Every authentic DCEC engine unit carries a standard factory-backed warranty coverage period of 12 months or 1,000 total running hours, whichever occurs first.
- Covered Components: This commercial warranty covers major structural elements, including the cylinder block casting, forged steel crankshaft, camshaft, and cylinder head sections, against manufacturing defects.
- Claim Resolution Process: If a covered component fails during the warranty period, HekoPower manages the engineering review and ships replacement components directly to your site to resolve the issue quickly.
Cummins B3.9-G Series, original products from Dongfeng Cummins Engine Plant (DCEC), Cummins Joint Venture Plant since 1986, 50% shareholding by Cummins USA. This series mainly includes 4B3.9-G1-24kw, 4B3.9-G2-24kw, 4BT3.9-G1-36kw, 4BT3.9-G2-36kw, 4BTA3.9-G2-50kw, 4BTA3.9-G2-58kw, 4BTA3.9-G11-70kw.In accordance with the criteria of Machinery Safety Directive 2006/42, movable elements such as distribution belts, fans, and parts that acquire high temperatures during operation, such as exhaust manifolds, have their respective safeguards. Before being delivered, the generator is thoroughly checked at the factory. Voltage, frequency, and load are all tested, as well as the appropriate operation of warnings and the influence of engine oil temperature on stop.
Technical FAQs
What is the exact Cummins 4BTA3.9-G2 fuel consumption at 100 percent load?
At 100% prime power load capacity at 1500RPM, the engine has a fuel consumption rate of 213 g/kW.h. This specific combustion rate equates to a fuel usage of roughly 12.9 to 13.5 liters of diesel per hour, depending on fuel quality, air filtration restrictions, and local site altitude.
Is this engine compatible with 60Hz power generation layouts?
The base 4BTA3.9-G2 model is configured as a 1500RPM Cummins genset engine for 50Hz applications. For 60Hz configurations requiring 1800RPM speeds, the internal governor counterweights and injection timing require adjustment. Contact the HekoPower technical team to order factory-set 60Hz engine options.
What components come included in the standard HekoPower power pack assembly?
Our standard product package includes the base engine block, the complete BYC fuel injection loop, a 24V electric starter motor, a matching charging alternator, a water pump, and primary filters. Custom additions like heavy-duty air cleaners, cooling radiators, and mounting rails can be installed based on your project requirements.
Is the 4BTA3.9-G2 suitable for continuous prime power operation?
Yes. The engine is commonly used in both standby and prime power generator applications when operated within rated specifications.
Can the engine operate in high-temperature environments?
The water-cooled turbocharged design supports operation in demanding ambient conditions when the cooling system is properly maintained.
Is this engine available as a complete power pack assembly?
Depending on project requirements, HekoPower may supply the engine as a complete assembly with cooling and accessory components.
How can customers confirm genuine DCEC origin?
Customers should verify engine nameplates, serial numbers, and supplier documentation before purchase.
