Details
DCEC Cummins B5.9-195G Natural Gas Engine Assembly (145 kW / 195 HP)
HekoPower is a global supplier and exporter of original Dongfeng Cummins (DCEC) engine assemblies. We supply complete, factory-tested Cummins B5.9-195G natural gas engines for bus manufacturers, commercial truck operators, and fleet maintenance specialists worldwide.
The DCEC B5.9-195G is a 5.9-liter, 6-cylinder in-line spark-ignited gas engine engineered specifically for compressed natural gas (CNG) and liquefied natural gas (LNG) commercial vehicles. Delivering 145 kW (195 HP) at 2,800 RPM and a maximum torque of 569 N.m at 1,600 RPM, this engine combines low fuel costs with high torque output under Euro II emission standards.
Built on the heavy-duty 5.9L engine block architecture, the B5.9-195G provides a proven mechanical design that operates efficiently without complex electronic aftertreatment systems.
Tech Specs of Cummins B5.9-195G
General Engine Data
Engine Model: Cummins B5.9-195G
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: 145 kW/195 HP
Rated Speed: 2800 rpm
Governed Speed: 2500 rpm
Max Torque/Speed: 569 N.m @ 1600 rpm
Fuel Consumption @ Rated Power: 239 g/Kw.h
Torque Available @ Clutch Engagement: 386 N.m
Max. Altitude for Continuous Opera: 2600 m
Torque/rated Speed: 496 N.m @ 2500 rpm
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 and Model Differentiation
Selecting the right replacement engine requires a precise understanding of how the Cummins B5.9-195G compares to other platforms in the 5.9L family. Minor differences in fueling, control systems, and internal metallurgy determine whether an engine assembly will install properly and perform reliably in your equipment.
B5.9-195G vs. BGe 195-31 (Mechanical Stoichiometric vs. Electronic Lean-Burn)
Although both engines share a 5.9-liter displacement, 6-cylinder inline block layout, and identical 145 kW (195 HP) power ratings, their control systems are fundamentally different.
The B5.9-195G operates on Euro II standards using a simple mechanical governor, a stoichiometric gas air-fuel mixer, and a dedicated ignition control system. This simple mechanical configuration makes the B5.9-195G tolerant of varying gas quality and extremely straightforward to service in regions with basic diagnostic infrastructure.
The Cummins BGe 195-31, on the other hand, is a Euro III compliant engine built around an electronic control unit (ECU), throttle-by-wire controls, and a closed-loop oxygen sensor system. Replacing a B5.9-195G with a BGe 195-31 requires replacing the vehicle wiring harness, installing electronic gas control modules, and adding extra chassis sensors. For legacy Euro II vehicle fleets, the original B5.9-195G remains the direct, economical replacement assembly.
B5.9-195G Natural Gas vs. 6BT 5.9 Diesel Platform
Fleet operators often ask whether a 6BT 5.9 diesel engine can be converted to a B5.9-195G natural gas engine using standard diesel service parts. While both engines share similar external mounting points and cylinder block dimensions, their internal components are completely different.
The B5.9-195G uses specialized pistons designed for a 10.5:1 compression ratio, whereas the 6BT diesel engine operates at a much higher 17.5:1 ratio. Additionally, the natural gas cylinder head features stellite-faced exhaust valves, induction-hardened valve seat inserts to prevent dry gas recession, and machined spark plug wells. Attempting to run a converted diesel block without gas-specific cylinder head metallurgy leads to rapid valve recession and piston failure.
B5.9-195G vs. B5.9-150G and B5.9-230G Power Ratings
The 5.9L DCEC gas engine family offers several power outputs to match specific vehicle weights and terrain conditions.
The entry-level B5.9-150G generates 112 kW (150 HP) at 2,500 RPM with 508 N.m of torque, making it suitable for light city buses and short-haul vehicles. The mid-range B5.9-195G provides 145 kW (195 HP) and 569 N.m of torque, offering the extra power needed for 9-to-11 meter transit buses and medium-duty delivery trucks operating under heavy payloads. For heavy-duty haulers requiring maximum climbing ability, the top-tier B5.9-230G produces 169 kW (230 HP) at 2,800 RPM.
Real Application Scenarios
The DCEC B5.9-195G natural gas engine is engineered for duty cycles that demand sustained torque, low fuel expenditure, and continuous operation.
Municipal Transit and City Buses
The B5.9-195G is widely deployed across 9-meter to 10.5-meter urban transit buses, shuttle fleets, and school buses. Its 569 N.m peak torque arrives early at 1,600 RPM, providing steady acceleration from passenger stops without excessive gear hunting. Operating on CNG or LNG helps municipal transit authorities reduce urban smoke and sulfur emissions while maintaining low fuel costs.
Commercial Medium and Heavy Trucks
For regional transport trucks, vocational vehicles, and municipal garbage compactors, the B5.9-195G serves as a clean-burning primary engine. Its compact dry weight of 413 kg minimizes payload impact on the front axle, leaving more capacity for commercial cargo.
Stationary and Mobile Power Packs
Beyond vehicle transport, complete B5.9-195G engine power packs are frequently installed in stationary natural gas compressor units, field fluid pumps, and mobile generator sets. Its continuous 2,800 RPM rating and direct fuel line compatibility make it an ideal prime mover where pipeline natural gas is readily available.
Maintenance, Ignition, and Replacement Guidelines
Proper servicing of spark-ignited gas engines requires specialized procedures that differ from routine diesel maintenance schedules.
Ignition System and Spark Plug Calibration
Natural gas requires higher spark voltage to ignite than gasoline or diesel fuel vapor. Maintain spark plug gaps at precisely 0.35 mm to 0.40 mm. Inspect ignition coils, spark plug boots, and high-tension cables every 15,000 kilometers. Cracks or oil contamination on the rubber boots cause voltage leakage to the cylinder head, resulting in misfires under engine load.
Gas Mixer and Pressure Regulator Servicing
Natural gas pipelines can transport small amounts of heavy oil condensate and dirt. Drain the oil collection trap on the primary gas pressure regulator monthly. Clean the gas air-fuel mixer diaphragm regularly to prevent carbon buildup from sticking the air valve, which causes hard starting and unstable idling.
CPL Verification for Complete Engine Replacement
When replacing a complete Cummins B5.9-195G engine, always check the Control Parts List (CPL) number printed on the engine dataplate located on the front timing gear cover. Matching the exact CPL number guarantees that your new replacement engine comes with the correct flywheel housing, 24V starter motor orientation, turbocharger wastegate setting, and gas supply bracket layout for your vehicle chassis.
Common Misconceptions About the Cummins B5.9-195G
Misconception 1: "The B5.9-195G Uses a Dual-Fuel Diesel Injection System"
A common misunderstanding among fleet operators is that the B5.9-195G injects a small amount of diesel fuel to ignite the natural gas charge. The B5.9-195G is a 100% dedicated spark-ignited gas engine. It has no diesel injection pump, high-pressure common rail system, or diesel injectors. It operates entirely on spark ignition fed by natural gas.
Misconception 2: "Standard Heavy-Duty Diesel Engine Oil Works Fine in Gas Engines"
Using standard CJ-4 or CK-4 heavy-duty diesel engine oil in a B5.9-195G will cause premature engine failure. Heavy-duty diesel oils contain high levels of metallic ash additives (often above 1.0%), which form hard combustion deposits on spark plug electrodes and hot valve faces. These deposits trigger pre-ignition and burn the valve seats. Always use low-ash natural gas engine oil (sulfated ash content 0.6% to 0.9%) meeting Cummins CES 20074 specifications.
DCEC Cummins Natural Gas Engine Series Integration
As an experienced supplier of genuine Dongfeng Cummins engine products, HekoPower provides complete power solutions for global vehicle fleets, power plant operators, and equipment manufacturers. We maintain a reliable supply of complete engine assemblies, long blocks, and original spare parts across the entire DCEC natural gas engine range.
To help fleet managers select the right power output, emission compliance, and fueling system for different commercial vehicle sizes, 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 lead time and shipping packaging for a complete B5.9-195G engine assembly?
HekoPower prepares complete, factory-tested DCEC B5.9-195G engine assemblies for export in approximately 10 business days. Each engine is secured inside a reinforced export wooden crate measuring 1200 x 900 x 1100 mm, with a total packed shipping weight of around 480 kg.
Is the B5.9-195G engine compatible with both CNG and LNG fuel?
Yes. The engine fuel induction system operates on both Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG), provided the primary regulator supplies fuel at the specified system pressure.
What components are included with a complete B5.9-195G engine assembly?
A complete assembly includes the short block, cylinder head, turbocharger, air-to-air intercooler pipe connectors, gas mixer, ignition harness, 24V starter motor, charging alternator, and flywheel assembly.
Does the complete B5.9-195G engine assembly include auxiliary components?
Yes. Complete engine assemblies supplied by HekoPower include the cylinder block, cylinder head, crankshaft, pistons, turbocharger, intake air mixer, gas pressure regulator, 24V starter motor, 24V alternator, water pump, and flywheel assembly.
Can HekoPower supply individual replacement parts for the B5.9-195G?
Yes. In addition to complete engine assemblies, HekoPower supplies original DCEC gas engine spare parts, including cylinder heads, gas-specific valve sets, spark plug coils, gas mixers, repair overhaul kits, and turbochargers.
