DCEC QSB4.5 Construction Machinery Engine: 109-132 HP Diesel Engine for Compact Excavators and Road Rollers

The Cummins QSB4.5-C is a 4.5-liter inline-four diesel engine delivering 109 to 132 HP at 2000-2500 RPM. Built by Dongfeng Cummins Engine Company (DCEC), the QSB4.5-C is the most compact and lightweight engine in the Cummins construction lineup — at just 600-800 kg, it’s designed for 5-10 ton excavators, small wheel loaders, compact road rollers, and portable pumps. The 4-cylinder configuration delivers smooth power with exceptional fuel economy, making it ideal for equipment operating in urban construction sites and tight spaces.

QSB4.5-C Engine Models and Performance Data

The QSB4.5-C lineup spans 109-132 HP across 6 models. The C109 and C110 variants prioritize fuel efficiency at lower RPM (2000-2200 RPM), perfect for compact road rollers and mini loaders. The C121, C128, C130A, and C132 models deliver higher torque for excavator and crane applications that demand more breakout force during digging cycles.

Construction Applications: Compact Excavators, Mini Loaders and Rollers

The QSB4.5-C is engineered for compact construction equipment where fuel economy, compact dimensions, and low weight are critical. Here’s how it performs across key applications:

Compact Excavators (5-10 Ton Class)

Compact excavators benefit most from lightweight, fuel-efficient engines. The QSB4.5-C at 600-800 kg is 25-30% lighter than the 5.9L QSB5.9-C, directly improving the excavator’s lift capacity and ground pressure distribution. The C128 and C130A models deliver 546-622 N·m peak torque — sufficient for trenching, grading, and utility work in urban construction sites where maneuverability is critical.

Common compact excavator platforms using QSB4.5-C engines include SANY SY60, XCMG XE80, and Kobelco SK75 series. Browse excavator parts and rebuild kits.

Mini Wheel Loaders (1-2 Ton Bucket Capacity)

Mini wheel loaders and skid-steer loaders need responsive torque in an ultra-compact package. The QSB4.5-C110 through QSB4.5-C130A offer 110-130 HP for 1-2 ton class loaders. The engine’s compact dimensions (1,050 mm × 810 mm × 810 mm) fit the tight engine compartments of compact articulated loaders and skid-steer loaders, leaving room for larger fuel tanks and hydraulic systems.

Compact Road Rollers and Compaction Equipment

Compact road rollers and compactors are the QSB4.5-C’s ideal application. The C109 and C110 variants deliver smooth, consistent torque at steady-state RPM — perfect for vibratory rollers that operate at constant speed for hours. The engine’s 600 kg weight reduces the roller’s total mass, allowing more weight allocation to the drum and tire assemblies for better compaction force in tight urban spaces.

Portable Water Pumps and Engine Power Packs

The QSB4.5-C is widely used in portable water pump sets and industrial engine power packs. Its compact size and light weight make it ideal for trailer-mounted pump units that need to be towed between job sites. The 6 model variants allow precise power matching to pump flow rate and pressure requirements, while the 4-cylinder design delivers smoother operation than 3-cylinder alternatives.

Key Technical Features of the QSB4.5-C

• High-Pressure Fuel System: The QSB4.5-C uses a rotary high-pressure fuel pump that delivers precise fuel injection timing. This improves combustion efficiency, reduces soot buildup, and lowers fuel consumption by 10-15% compared to older inline pump designs.
• Holset Wastegate Turbocharger: Cummins’ Holset turbo optimizes boost pressure across the RPM range. The wastegate prevents over-boosting at high RPM, protecting the engine during prolonged full-throttle operation.
• Platform Honing Cylinder Liner: The cylinder liner surface is honed using a plateau technique that creates micro-grooves for oil retention. This reduces piston ring friction by 15-20%, extending engine life and improving fuel economy.
• Forged Steel Crankshaft: Induction-hardened journals handle torsional loads from hydraulic pumps and torque converters. The 5-main-bearing design minimizes flex under heavy load, reducing bearing wear.
• Ultra-Compact Design: At 600-800 kg dry weight and 1,050 mm length, the QSB4.5-C is 50-55% lighter than comparable 13L engines. This dramatic weight savings improves equipment payload capacity, reduces fuel consumption, and lowers transport costs.
• 4-Cylinder Smoothness: The inline-4 configuration with balance shafts delivers smoother operation than 3-cylinder alternatives, reducing vibration and noise — critical for urban construction sites where operator comfort and noise regulations matter.

DCEC Manufacturing: Dongfeng Cummins Joint Venture

The QSB4.5-C is manufactured by Dongfeng Cummins Engine Co., Ltd. (DCEC), a 50-50 joint venture established in 1986 between Dongfeng Motor Corporation and Cummins Inc. DCEC’s facility in Shiyan, Hubei Province uses Cummins’ global engineering standards and quality control systems.

Key manufacturing advantages of DCEC-produced QSB4.5-C engines:

• Cummins technology transfer: All QSB4.5-C engines use Cummins-designed cylinder blocks, cylinder heads, and fuel systems — identical to B4.5 engines built in the US and UK.
• ISO 9001 and IATF 16949 certification: DCEC’s quality management system meets automotive-grade standards for defect prevention and continuous improvement.
• Cost competitiveness: Chinese manufacturing reduces production costs by 20-30% compared to US or UK-built Cummins engines, without sacrificing quality or reliability.
• Global parts interchangeability: QSB4.5-C parts are compatible with Cummins B4.5 engines built in other regions, simplifying sourcing for multi-region fleets.

Learn more about Cummins engine platforms and DCEC product lines.

Maintenance Intervals and Overhaul Costs

The QSB4.5-C is designed for 6,000-8,000 hour service intervals under normal construction duty. Key maintenance points:

• Oil and filter change: Every 250 hours (standard) or 500 hours (extended service with synthetic oil). Use 15W-40 API CJ-4 or CK-4 grade oil.
• Fuel filter replacement: Every 500 hours. High-pressure fuel systems require clean fuel to prevent pump and injector wear.
• Coolant system flush: Every 2,000 hours or 2 years. Use Cummins Extended Life Coolant (ELC) to prevent cavitation erosion of cylinder liners.
• Valve adjustment: Every 4,000 hours. Overhead valve design requires periodic lash adjustment to maintain compression and fuel efficiency.
• Major overhaul: At 8,000-10,000 hours. Includes piston, liner, bearing, and gasket replacement. Complete QSB4.5 overhaul kits available.

Typical overhaul cost for a QSB4.5-C is $2,800-$4,500 (parts and labor), depending on component wear. This compares favorably to replacing the engine outright ($7,500-$11,000 for a new QSB4.5-C).

QSB4.5-C vs. Competitor Engines: How Does It Compare?

The 4.5-liter engine class is competitive. Here’s how the QSB4.5-C stacks up against comparable models:

• vs. Cummins QSB5.9: The QSB5.9 is a larger 5.9L engine (130-210 HP). The QSB4.5-C is 25-30% lighter and more compact, preferred for 5-8 ton excavators where the QSB5.9’s extra power is not needed and weight savings are more valuable.
• vs. Deutz TCD2011: The Deutz TCD2011 is a 3.6L engine (80-120 HP). The QSB4.5-C offers 25% more displacement and higher torque, better suited for excavator and crane applications that demand more breakout force.
• vs. Isuzu 4JJ1: The Isuzu 4JJ1 is a 3.0L engine (120-170 HP). The QSB4.5-C’s larger displacement delivers higher torque at lower RPM, plus broader global parts availability and lower overhaul costs in emerging markets.

Why Choose BLSH Diesel for QSB4.5-C Engines and Parts?

• Direct DCEC supply chain: We source QSB4.5-C engines and parts directly from authorized DCEC distributors, ensuring genuine Cummins components with full warranty coverage.
• Complete engine inventory: QSB4.5-C109 through QSB4.5-C132 models in stock, plus overhaul kits, cylinder liners, pistons, crankshafts, turbochargers, and fuel system components.
• Technical support: Our team includes former Cummins service technicians who can assist with engine selection, installation, and troubleshooting.
• Global shipping: We ship to 60+ countries. Standard QSB4.5-C engines are packed in seaworthy wooden crates with desiccant to prevent corrosion during ocean freight.

Compare QSB4.5-C with other DCEC industrial engines or explore construction machinery parts.