QSB5.9 Piston 3948465 for Cummins Engine Parts | Construction, Industrial, Marine

Product Details

Product Overview

This premium replacement piston, part number 3948465, is engineered specifically for the Cummins QSB5.9 diesel engine platform. As a critical component within the power cylinder assembly, this piston is designed to withstand the high pressures and temperatures inherent in turbocharged, heavy-duty diesel applications.

Manufactured to OEM size and specifications, this piston is commonly used across a wide range of equipment, including construction machinery, industrial generators, agricultural tractors, marine propulsion systems, and material handling equipment. It serves as a direct, high-quality replacement for worn or damaged components, ensuring restored engine compression and power output.

Key Features & Benefits

• Precision Fitment: Machined to OEM dimensional tolerances for seamless installation into the QSB5.9 engine block, reducing downtime and ensuring reliable ring seal.
• High-Temperature Durability: Constructed from high-strength aluminum alloy, designed to resist thermal expansion and structural fatigue under continuous heavy-load operation.
• Enhanced Compression: Restores factory compression ratios, optimizing fuel efficiency and reducing white smoke or hard starting common with worn pistons.
• Oversized Compatibility: Available in standard OEM size; also compatible with standard ring sets (part number 3969310) and cylinder liners for a complete rebuild solution.
• Rigorous Testing: Each batch undergoes dimensional verification and material hardness testing to ensure consistency and long service life.
• Application Versatility: Suitable for both naturally aspirated and turbocharged variants of the QSB5.9, covering a wide spectrum of industrial and mobile equipment.

Technical Specifications

OEM Cross-Reference

This piston is a direct replacement for the following OEM and reference numbers:

• Cummins OEM: 3948465
• Associated Ring Set: 3969310
• Alternative Reference: 3803262 (Superseded)

Note: Always confirm the crown profile and pin bore diameter with your existing piston before installation.

Compatibility

This piston is commonly used for the following applications and engine variants:

• Engine Models: Cummins QSB5.9, QSB5.9-G (Genset), QSB5.9-C (Construction)
• Equipment Types: Excavators (e.g., Komatsu PC200-8), Wheel Loaders (e.g., XCMG ZL50), Agricultural Tractors, Marine Auxiliary Engines, Industrial Generator Sets
• System Fitment: Standard bore size; compatible with standard connecting rods and piston pin (diameter 40mm typical).

Disclaimer: This is a replacement part. While designed for the listed engine families, we recommend verifying fitment with your specific engine serial number to ensure compatibility with any OEM updates.

Global Supply & Distribution

We provide reliable global logistics to support B2B buyers and maintenance operations worldwide. Our export capabilities include:

• Major Ports Served: Rotterdam, Antwerp, Hamburg (Europe); Los Angeles, Houston, Miami (North America); Dubai, Jebel Ali (Middle East); Singapore, Shanghai, Busan (Asia-Pacific).
• Shipping Options: Sea freight (FCL/LCL), air express (DHL, FedEx, UPS), and rail freight for inland destinations.
• Lead Times: 3-7 days for express, 15-25 days for sea freight from Shenzhen or Guangzhou ports.
• Market Experience: Consistent supply to North American equipment dealers, European industrial rebuild shops, and African mining operations.

Quality Assurance

Every piston is manufactured under strict quality control procedures to ensure reliability in demanding environments.

• Standards: Production follows ISO 9001 guidelines for dimensional control and material traceability.
• Inspection: Machinery Test Report and Video Outgoing Inspection are available upon request for each batch.
• Warranty: 6-month warranty against manufacturing defects. After-warranty online support is provided for technical queries.
• Packaging: Individually wrapped to prevent damage during transit, with bulk carton options for volume orders.

FAQ

Q: How do I confirm this piston fits my specific QSB5.9 engine?
A: Verify the engine serial number (ESN) on your engine data plate. This piston is designed for standard bore QSB5.9 engines. If your engine has been previously rebored, you may require an oversized piston. Measure the cylinder bore diameter and compare it to the OEM specification (102mm standard).

Q: What other parts should I replace when installing this piston?
A: For a complete top-end overhaul, we recommend replacing the piston rings (Cummins 3969310), cylinder liners, and connecting rod bearings simultaneously. Always use new gaskets and seals for the cylinder head and oil pan. This ensures even wear and prevents premature failure.

Q: What is the typical installation procedure for this piston?
A: Clean the cylinder bore thoroughly. Lubricate the piston skirt, rings, and cylinder wall with clean engine oil. Use a piston ring compressor to gently slide the piston into the bore, ensuring the arrow on the piston crown points toward the front of the engine. Torque the connecting rod bolts to the manufacturer’s specification (typically 80-90 ft-lbs for QSB5.9).