Product Description

The Cummins 4B3.9-G12 Generator Drive Engine is a 3.9L, 4-cylinder, naturally aspirated diesel engine manufactured by Dongfeng Cummins. It delivers up to 36 kW (49 HP) at 1800 rpm and 30 kW (41 HP) at 1500 rpm, making it ideal for compact generator sets serving residential, commercial, and light industrial power generation.

With a direct injection fuel system, electronic governor, and simple robust design, the 4B3.9-G12 offers low fuel consumption, high reliability, and ease of maintenance.

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Specifications

• Engine Model: Cummins 4B3.9-G12
• Application: Generator Drive Engine
• Displacement: 3.9 L
• Configuration: 4-cylinder, in-line, 4-cycle
• Bore × Stroke: 102 × 120 mm
• Compression Ratio: 18.0:1
• Aspiration: Naturally Aspirated
• Fuel System: Weifu A Direct Injection with Electronic Governor

• Governor Regulation: ≤3%

Power Ratings:

• 1500 rpm (50Hz): Standby: 30 kW/ 41 HP; Prime: 27 kW/ 37 HP

• 1800 rpm (60Hz): Standby: 36 kW/ 49 HP; Prime: 33 kW/ 45 HP

Fuel Consumption (1500 rpm):

• 1500 rpm (50Hz): Standby: 8.0 L/h (221 g/kW.h); Prime: 7.4 L/h (227 g/kW.h)
• 1800 rpm (60Hz): Standby: 10.1 L/h (10.1 g/kW.h); Prime: 9.4 L/h (9.4 g/kW.h)

Weight: ~308 kg (wet)

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Product Advantages

• Higher Output – Provides up to 36 kW at 1800 rpm, suitable for larger small gensets.
• Fuel Efficient – Low consumption: 3.0–10.1 L/h depending on load.
• Stable Performance – Electronic governor with ≤3% regulation for steady frequency.
• Durable Build – Proven Cummins 4-cylinder design ensures reliability.

• Genuine Cummins Support – Backed by worldwide Cummins service and spare parts.

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Key Features

• Dual-frequency operation: 1500 rpm (50Hz) and 1800 rpm (60Hz).
• Compact size with only 308 kg wet weight.
• Weifu A pump direct injection for efficient fuel delivery.
• Designed to meet GB/T18297 test conditions.

• Reliable starting with 12V/24V heavy-duty starter motor.

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Applications

The Cummins 4B3.9-G12 Diesel Engine for Generator Sets is ideal for:

• Residential Backup Power – small homes and apartments.
• Light Commercial Power – retail shops, offices, and telecom.
• Agricultural Use – rural electrification and farm operations.

• Portable & Rental Generators – mobile and compact gensets.

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Product Availability

The Cummins 4B3.9-G12 Generator Drive Engine is available globally with genuine Cummins warranty, technical service, and spare parts support, ensuring reliable long-term power generation.