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Cummins 6BT5.9-G1 Engine

The Cummins 6BT5.9-G1 is a 5.9-liter, inline 6-cylinder, 4-stroke, turbocharged diesel engine. It is specifically engineered as a G-Drive power unit intended primarily for stationary generator sets. Characterized by a highly reliable mechanical design, this heavy-duty industrial engine features a 12-valve configuration with an integrated, heavy-duty cylinder block and single-piece cast head. The robust architecture reduces components by nearly 40% compared to conventional engines in its class, significantly mitigating fluid leak paths and lowering mechanical failure rates. The design utilizes plateau-honed cylinders paired with high-rigidity, forged steel I-beam section connecting rods and a forged crankshaft to guarantee prolonged service life under continuous duty applications.

Fuel delivery is governed by a purely mechanical, direct-injection configuration. The system relies on a heavy-duty, inline high-pressure injection pump (Weifu A-type or BYC PB-type) synchronized with a mechanical RSV governor or an optional GAC electrical governor for precise speed droop control within a 5% to 8% regulation tolerance. Fuel conditioning is performed through a dedicated Fleetguard spin-on fuel filter assembly with integrated water separation capabilities.

The engine uses a pressurized, wet-sump lubrication system managed by an engine-driven, high-capacity oil pump. It features a standard full-flow oil pan equipped with specialized platform mesh honing to maintain a perfect geometric seal and prevent premature oil consumption or loss. Maintenance filtration is managed via a spin-on Fleetguard full-flow lube oil filter. The oil pan provides structural flexibility, allowing operation with a permissible static bias tilt angle of up to 40 deg in front-up, front-down, or side-to-side orientations.

Engine thermal regulation relies on a closed-loop liquid cooling system utilizing an engine-mounted, jacket water-driven water pump. The assembly interfaces directly with an integrated, set-mounted radiator core and fan assembly designed to handle heavy industrial heat rejection requirements. The design includes a jacket water aftercooler circuit to reduce the temperature of incoming compressed intake air, ensuring proper combustion temperatures and sustained thermal balance.

General Technical Data

Engine Specifications

Engine Model ............... Cummins 6BT5.9-G1
Engine Type ............... 4-cycle inline 6-cylinder direct injection turbocharged liquid-cooled diesel
Number of Cylinders ............... 6
Cylinder Arrangement ............... In-line
Engine Bore, in (mm) ............... 4.02 (102.0)
Engine Stroke, in (mm) ............... 4.72 (120.0)
Displacement, cu.in (L) ............... 359 (5.9)
Rated Engine Power, hp (kW) ............... 160-220 (120-165)
Rated Engine Speed, rpm ............... 1500-1800
Peak Torque ............... 650-800 Nm (479-590 lb-ft) at 1200-1400 rpm
Idle Speed ............... 700-800 rpm
Aspiration Type ............... Turbocharged
Compression Ratio ............... 17.5:1
Firing Order ............... 1-5-3-6-2-4
Cylinder Block Type ............... Cast iron
Cylinder Head Type ............... Cast iron
Lubrication System ............... Full-pressure
Oil Pump Type ............... Gear-driven
Oil Filter Type ............... Full-flow, spin-on
Cooling System ............... Liquid-cooled
Water Pump Type ............... Belt-driven, centrifugal
Air Cleaner Type ............... Dry dual-stage
Starting System ............... Electric Starter
Electrical System ............... 12V or 24V
Alternator Rating, Amps ............... 35-70

Fuel System

Fuel System ............... Direct injection
Injection Pump Type ............... Rotary or inline
Fuel System Control ............... Mechanical
Governor Type ............... Mechanical
Fuel Injector Type ............... Multi-hole
Fuel Type ............... Diesel Fuel

Dimensions and Weight

Overall Length, in (mm) ............... 41.3-45.2 (1050-1150)
Overall Width, in (mm) ............... 27.6-31.5 (700-800)
Overall Height, in (mm) ............... 39.4-49.3 (1000-1150)
Dry Weight, lbs (kg) ............... 945-1100 (430-500)

Maintenance Data

Service Information

Thermostat begins opening ............... 82C (180F)
Thermostat fully open ............... 95C (203F)
Cooling system pressure ............... 70-100 kPa (10-15 psi)
Operating oil pressure ............... 300-450 kPa (44-65 psi)
Idle oil pressure ............... 100-150 kPa (15-22 psi)
Intake Valve Clearance, in (mm) ............... 0.254 (0.010)
Exhaust Valve Clearance, in (mm) ............... 0.508 (0.020)

Engine Oil and Coolant

Engine Oil Type .................. SAE 10W-30, 15W-40
API Service Classifications ......................... CI-4, CJ-4, or CK-4
Engine Oil Capacity, qts (L) .................. 13.6-16.8 (13.0-16.0)
Coolant Capacity, qts (L) ............... 21.0-26.3 (20.0-25.0)

Service Intervals

Change oil and filter ............... Every 250 hours
Replace fuel filters ............... Every 300 hours
Inspect air filter ............... Every 100 hours
Replace air filter ............... Every 300 hours
Change coolant ............... Every 2000 hours
Valve-lash adjustment ............... Every 1000 hours
Injector inspection ............... Every 1500-2000 hours
Compression test ............... Every 2500 hours
Drain water separator ............... As required
Belt inspection ............... As required

Service Specifications

Cylinder Bore Inside Diameter, in (mm) ............... 4.0165-4.0177 (102.000-102.030)
Crankshaft Journal Outside Diameter, in (mm) ............... 3.2672-3.2682 (82.987-83.013)
Crank Pin Outside Diameter, in (mm) ............... 2.7160-2.7170 (68.987-69.013)
Crankshaft End Play, in (mm) ............... 0.0040-0.0130 (0.102-0.330)
Intake Valve Stem Outside Diameter, in (mm) ............... 0.3129-0.3139 (7.947-7.973)
Exhaust Valve Stem Outside Diameter, in (mm) ............... 0.3121-0.3131 (7.927-7.953)
Intake Valve Guide Inside Diameter, in (mm) ............... 0.3154-0.3169 (8.011-8.049)
Exhaust Valve Guide Inside Diameter, in (mm) ............... 0.3154-0.3169 (8.011-8.049)
Intake Valve Stem to Guide Clearance, in (mm) ............... 0.0015-0.0040 (0.038-0.102)
Exhaust Valve Stem to Guide Clearance, in (mm) ............... 0.0023-0.0048 (0.058-0.122)
Intake Valve Spring Free Length, in (mm) ............... 1.879 (47.73)
Exhaust Valve Spring Free Length, in (mm) ............... 1.879 (47.73)
Intake Cam Height, in (mm) ............... 1.8482-1.8612 (46.945-47.275)
Exhaust Cam Height, in (mm) ............... 1.8385-1.8540 (46.697-47.091)
Piston Pin Outside Diameter, in (mm) ............... 1.5746-1.5750 (39.995-40.005)
Piston Pin to Piston Bore Clearance, in (mm) ............... 0.0003-0.0007 (0.008-0.018)
Second Ring Side Clearance, in (mm) ............... 0.0027-0.0045 (0.068-0.115)
Oil Ring Side Clearance, in (mm) ............... 0.0015-0.0033 (0.038-0.085)
Top Ring End Gap, in (mm) ............... 0.0100-0.0220 (0.254-0.559)
Second Ring End Gap, in (mm) ............... 0.0100-0.0220 (0.254-0.559)
Oil Ring End Gap, in (mm) ............... 0.0100-0.0220 (0.254-0.559)

Tightening Torque Specs

Cylinder-head bolts ............... 190-210 Nm (140-155 lb-ft)
Main-bearing caps ............... 245-260 Nm (181-192 lb-ft)
Connecting-rod bolts ............... 75-85 Nm (55-63 lb-ft)
Flywheel bolts ............... 135-150 Nm (100-111 lb-ft)
Crankshaft damper bolt ............... 270-300 Nm (199-221 lb-ft)
Oil drain plug ............... 40-50 Nm (30-37 lb-ft)
Injector hold-down ............... 25-30 Nm (18-22 lb-ft)

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• Cummins Engines Specs
  
• Cummins 6B5.9 Specs
  
• Cummins 6BT5.9-G2 Specs
  
• Cummins 6BTA5.9 Specs
  
• Cummins 6BTAA5.9-G12 Specs
  

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