Details
DCEC Cummins B5.9-150G Natural Gas Engine Assembly
The DCEC Cummins B5.9-150G is a 5.9-liter, 6-cylinder in-line natural gas vehicle engine engineered by Dongfeng Cummins Engine Company. Delivering a rated power output of 112kW (150HP) at 2500 RPM and peak torque of 375 lb-ft at 1500 RPM, this gas engine provides reliable, low-emission power tailored for urban transport and commercial service fleets.
As a specialized exporter and supplier of genuine engine assemblies, HekoPower supplies complete Cummins B5.9-150G replacement engine units and matching vehicle power packs. Whether you are replacing an end-of-life bus engine or upgrading commercial trucks to meet city natural gas standards, obtaining an original DCEC B5.9-150G engine ensures seamless mechanical installation and immediate operational reliability.
Tech Specs of Cummins B5.9-150G
General Engine Data
Engine Model: Cummins B5.9-150G
Type: 6 Cylinders in Line
Displacement: 5.9 L
Bore * Stroke: 102 * 120
Net Weight (with flywheel & alternator): 413 Kg
Overall Dimension: 1026mm*699mm*912mm
Key Performance Data
Rated Power: 112 kW/150 HP
Rated Speed: 2500 rpm
Max Torque/Speed: 508 N.m @ 1500 rpm
Fuel Consumption @ Rated Power: 232 g/Kw.h
Torque/rated Speed: 427 N.m @ 2500 rpm
Torque Available @ Clutch Engagement: 386 N.m
Max. Altitude for Continuous Opera: 2700 m
More Technical Data
Certification: Euro II
Aspiration: Turbocharged & Air-Air Intercooled
Fuel System: Cummins Fuel System
Compression Radio: 10.5:1
Starting System: Electrical Starting Motor 24V(510A)
Lowest Starting Temp Without auxiliary system: -10℃/-25℃
Cooling Method: Water cooled
Engine Cooling Fluid Volume: 12.3 L
Technical Comparisons: B5.9-150G vs Related Engine Models
Choosing the correct engine requires understanding how the B5.9-150G differs from diesel models and other natural gas variants in the DCEC lineup. The following comparison highlights key technical differences without relying on standard spec tables.
Cummins B5.9 Gas vs Diesel Engine (B5.9-150G vs 6BT5.9 / ISB5.9)
A frequent point of confusion among buyers is assuming the B5.9-150G is simply a modified 6BT5.9 or ISB5.9 diesel engine. Structurally, the cylinder block dimensions are identical, but the internal hardware and cylinder head design differ completely.
The B5.9-150G uses a spark-ignited combustion chamber operating at a lower compression ratio designed specifically for gaseous fuel. High-pressure diesel fuel injectors and fuel injection pumps are replaced with spark plugs, ignition coils, and a gas-air mixer. The cylinder head features hardened valve seat inserts and high-temperature alloy valves capable of enduring the elevated exhaust gas temperatures of natural gas combustion. Attempting to convert a diesel 6BT5.9 or ISB5.9 to run CNG by swapping top-end parts is impractical due to these fundamental thermodynamic differences.
Cummins B5.9-150G vs B5.9-160G and B5.9-195G
Within the DCEC natural gas series, the B5.9 platform offers several output tiers, including the B5.9-150G (150HP), B5.9-160G (160HP), and B5.9-195G (195HP). The underlying mechanical displacement across all three models remains 5.9 liters.
The power variation comes from ECU calibration, turbocharger wastegate pressure settings, and gas mixer sizing. The B5.9-150G 150HP engine is calibrated specifically for lower thermal stress and high fuel economy in urban operations. Higher-horsepower models like the B5.9-195G generate additional power for heavier loads but demand greater cooling capacity. For transit buses operating on flat city routes, the B5.9-150G delivers superior component longevity and lower long-term fuel consumption.
Real Application Scenarios
The B5.9-150G commercial vehicle engine serves specific transport sectors that require low exhaust emissions and low noise output.
City Transit Buses & Municipal Fleets
Public transport fleets widely utilize the B5.9-150G bus engine in 8-meter to 10-meter city transit buses. CNG combustion produces virtually zero particulate matter (PM), making this model ideal for urban clean-air zones. The engine delivers smooth acceleration at lower RPMs, reducing gear shifting strain for drivers and providing a quieter ride for passengers.
Medium-Duty Commercial Trucks & Delivery Vehicles
As a dedicated B5.9-150G truck engine, this unit powers urban refuse trucks, medium-duty cargo trucks, and municipal maintenance vehicles. Fleet operators running on natural gas benefit from predictable fuel costs and compliance with strict local environmental regulations.
Complete Engine Replacement & Power Pack Retrofits
When an existing vehicle power pack reaches the end of its service life, replacing the unit with a complete original DCEC B5.9-150G engine assembly saves significant shop labor. A factory-assembled unit includes the complete fuel system, wiring harness connectors, and turbocharger pre-installed, preventing installation errors associated with rebuilding worn sub-assemblies.
Field Maintenance & Engine Replacement Tips
Proper maintenance practices ensure long service life and prevent premature failure in natural gas engines.
Use Low-Ash Natural Gas Oil: Never use standard diesel engine oil in the Cummins B5.9-150G. Natural gas burns cleaner than diesel but operates at higher combustion temperatures. Standard heavy-duty diesel oils contain ash additives that form hard metallic deposits on spark plugs and valve seats. Always select oil formulated specifically for CNG/LNG engines with low ash content (typically under 0.6% to 0.9%).
Monitor Spark Plugs and Ignition System: Because natural gas requires higher ignition voltage than gasoline, spark plug gaps must be inspected regularly according to the maintenance manual. Worn spark plugs or leaking ignition boots put excess strain on the ignition coil module, leading to engine misfires under load.
Verify Engine Model Identification & CPL: Before placing an order for a replacement Cummins B5.9-150G complete engine, always check the engine dataplate on the timing gear housing. Record the full model designation, serial number, and CPL (Control Parts List) number. Matching the exact CPL guarantees that the replacement engine assembly connects directly to your vehicle's existing throttle linkages, gas supply line, and ECU wiring.
Common Misconceptions About the B5.9-150G
Clearing up common myths helps fleet managers make informed purchasing decisions:
Misconception: Natural gas engines lack the low-end torque of diesel engines.
Fact: While natural gas burns differently than diesel, the turbocharger on the B5.9-150G is matched to deliver peak torque (375 lb-ft) at just 1500 RPM. This provides ample pulling power from a complete stop.
Misconception: Any B5.9 diesel cylinder head can fit a B5.9 gas block.
Fact: CNG engines operate at significantly higher combustion temperatures. The B5.9-150G utilizes special alloy valve seats and specific spark plug porting that standard diesel heads lack.
DCEC Cummins Gas Engine Series Options
HekoPower exports a full selection of original Dongfeng Cummins gas engines and replacement components to support global vehicle fleets and industrial operators.
DCEC Gas Engine Series, original products from Dongfeng Cummins Engine Plant (DCEC), Cummins Joint Venture Plant since 1986, 50% shareholding by Cummins USA. This series mainly includes B5.9-150G, BGe 150-30, B5.9-195G, BGe 195-31, BGe 200-30, B5.9-230G, BGe 230-31.
Frequently Asked Questions (FAQ)
What is the rated power and torque of the Cummins B5.9-150G engine?
The DCEC Cummins B5.9-150G natural gas engine produces a rated output of 112kW (150HP) at 2500 RPM and maximum torque of 375 lb-ft at 1500 RPM.
Is this engine original Cummins?
Yes, all engines supplied are genuine DCEC Cummins products.
Can I replace an older diesel 6BT engine with a complete B5.9-150G gas engine?
Yes, but retrofitting requires installing a natural gas fuel storage tank, gas pressure regulators, gas supply lines, and matching engine management wiring. Physical engine mounting points on the chassis remain identical.
How can I verify if a replacement B5.9-150G engine fits my bus or truck?
Provide your current engine serial number and CPL number to the HekoPower sales team. We verify internal specifications and external plumbing configurations to match your exact vehicle layout.
