Cummins 4BTAA3.3-G11 Specifications
| Engine Model: Cummins 4BTAA3.3-G11 |
| Engine Type: 4-cycle inline 4-cylinder direct injection liquid-cooled diesel |
| Total Displacement: 199 cu.in (3.3 L) |
| Rated Engine Power: 67-88 Hp (50-66 kW) at 1800 rpm |
| Aspiration Type: Turbocharged and aftercooled |
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The Cummins 4BTAA3.3-G11 is a compact,
turbocharged and aftercooled industrial diesel engine belonging to the
Cummins 3.3-liter engine family. This model is most commonly used in
generator drives, construction machinery, agricultural equipment,
pumping systems, and industrial stationary power units. The 4BTAA3.3-G11
is engineered to provide robust performance, exceptional reliability,
high fuel efficiency, and long service intervals–qualities that have
made Cummins small-bore engines some of the most trusted in the
industrial equipment world.
The G11 generator-drive configuration features turbocharging with
air-to-air aftercooling to increase power density, maintain stable
output under continuous duty, and deliver excellent thermal efficiency.
The mechanical fuel system makes the engine easy to service in remote
environments and resistant to fuel contamination. Its compact structure
and durable cast-iron components allow the engine to handle high
vibration, dusty conditions, high-hour operation, and severe industrial
environments.
The Cummins 4BTAA3.3-G11 is a four-stroke, water-cooled, inline
four-cylinder diesel engine with a displacement of approximately 3.3
liters (199 cubic inches). Bore is typically 95 mm (3.74 in) and stroke
is 115 mm (4.53 in), enabling a long-stroke configuration optimized for
torque and fuel efficiency.
Compression ratio: approximately 17.5:1. Peak torque: Approximately
220–300 Nm (162–221 lb-ft) @ 1,400–1,600 rpm. Idle speed: 750–900 rpm.
Governed speed: 1,500 or 1,800 rpm. Firing order: 1-3-4-2. Turbocharging
and aftercooling significantly increase power density and improve
altitude performance.
Power output (depending on generator
frequency and configuration):
– Prime: 45–60 kW (60–80 hp) @ 1,500–1,800 rpm
– Standby: 50–66 kW (67–88 hp) @ 1,500–1,800 rpm
The crankshaft is forged steel, precision-balanced, and supported by
five main bearings. Pistons are aluminum alloy with reinforced crowns
and internal cooling galleries. Connecting rods are forged steel with
replaceable bearing inserts. The camshaft is gear-driven and located
within the block, providing long-term timing stability.
The engine block is a high-strength cast-iron unit with integrated
parent-bore cylinders.
It features:
– Deep skirt block for added stiffness
– Reinforced ribbing for vibration resistance
– Wide main-bearing saddles
– Full-length coolant passages surrounding all cylinders
Parent-bore construction supports multiple overhauls if machining
tolerances remain within specifications.
The cast-iron cylinder head incorporates:
– Two valves per cylinder
– Direct-injection combustion chambers
– Hardened valve seats and guides
– Rocker-arm valvetrain with mechanical adjusters
Cold valve-lash settings:
– Intake: 0.254 mm (0.010 in)
– Exhaust: 0.508 mm (0.020 in)
The head is designed for high thermal stability and continuous full-load
operation typical of generator and industrial use.
The 4BTAA3.3-G11 uses a fully mechanical direct-injection fuel system
for maximum reliability.
The system includes:
– Mechanical lift pump
– Inline mechanical injection pump
– Multi-hole mechanical injectors
– Dual filtration (primary separator + secondary fine filter)
Injection pressures: approximately 250–350 bar.
Fuel-system maintenance:
– Replace filters every 250–300 hr
– Drain water separator daily or as needed
– Injector inspection every 1,000–1,500 hr
– Injection-pump timing check at major service intervals.
A full-pressure wet-sump lubrication system is used.
A gear-driven oil pump supplies lubricating pressure.
Oil capacity: 8–10 liters (8.5–10.6 qt)
Oil pressure:
– Operating: 275–380 kPa (40–55 psi)
– Idle: 70–100 kPa (10–15 psi)
Recommended lubricants: SAE 15W-40 diesel engine oils meeting API CI-4,
CJ-4, or CK-4
Oil-change interval: 250 hours under generator-set duty.
Cooling is achieved with:
– Belt-driven centrifugal water pump
– Thermostat-controlled coolant flow
– Radiator or remote cooling options
Thermostat:
– Opening temperature: 82°C (180°F)
– Full open: 95°C (203°F)
Cooling-system capacity: 10–14 liters (10.6–14.8 qt)
System pressure: 70–100 kPa (10–15 psi).
| Intake and Exhaust Systems |
Air intake:
– Dry-type filters
– Optional dual-stage filtration
– Optional cyclone pre-cleaners
Turbocharging:
– Fixed-geometry turbocharger
– Engine-oil lubrication of turbo bearings
Aftercooling:
– Air-to-air charge-air cooler (ATAAC)
– Reduces intake temperature for improved power and durability
Exhaust:
– Cast-iron manifold
– Industrial exhaust elbows optional.
| Electrical and Starting Systems |
Standard electrical options:
– 12V or 24V starting system
– Alternator: 35–70 amps
– Sensors: oil pressure, coolant temperature, tachometer signal
There is no ECM; the system is purely mechanical.
Available drive and accessory systems
include:
– PTO pulley drives
– Hydraulic pump drives
– Generator head adapter housings
– Belt-driven auxiliaries
– Remote radiator setups.
Approximate physical dimensions:
– Length: 850–1,000 mm (33–39 in)
– Width: 650–750 mm (26–30 in)
– Height: 900–1,050 mm (35–41 in)
Dry weight: 260–330 kg (573–728 lb).
– Oil and filter: every 250 hr
– Fuel filters: 250–300 hr
– Air filter: inspect every 50–100 hr
– Valve adjustment: every 1,000 hr
– Injector service: every 1,000–1,500 hr
– Coolant replacement: every 2 years
– Compression test: every 2,000 hr
– Belt inspection: each service.
– Cylinder head bolts: 135–150 Nm (100–111 lb-ft) + angle torque
– Main-bearing caps: 175–190 Nm (129–140 lb-ft)
– Connecting-rod bolts: 65–75 Nm (48–55 lb-ft)
– Flywheel bolts: 100–120 Nm (74–89 lb-ft)
– Crankshaft pulley bolt: 200–225 Nm (148–166 lb-ft)
– Oil drain plug: 40–50 Nm (30–37 lb-ft)
– Injector hold-downs: 20–25 Nm (15–18 lb-ft).
The Cummins 4BTAA3.3-G11 is widely used in:
– Diesel generator sets (40–70 kW class)
– Agricultural tractors
– Skid-steer and compact loaders
– Forklifts
– Telehandlers
– Industrial pumps
– Irrigation engines
– Air compressors
– Construction site power units.
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