Engine Piston Kit Cummins 4089462 | 4089725, 3939398, 3969000

High-Performance Engine Piston Kit for Cummins B4.5 and QSB4.5 Engines

Ensure your heavy-duty diesel engine operates at peak performance with this premium engine piston kit, part number 4089462. Designed specifically for Cummins B4.5, ISB 4.5, and QSB4.5 engines, this standard-size (STD) piston kit is engineered to withstand extreme combustion temperatures and pressures, restoring optimal compression and reducing blow-by.

This part is also available under the numbers: 4089725, 3939398, 3969000, and 4089460. It features an Alfin insert for enhanced piston ring groove durability, ensuring a longer service life and superior resistance to wear in demanding industrial, agricultural, and commercial applications.

Technical Specifications:

• Engine Compatibility: Cummins B4.5, QSB4.5, ISB 4.5
• Piston Diameter: 102 mm (Standard / STD)
• Piston Rings: 3.00T x 2.50 x 4.00 mm
• Piston Pin Dimensions: 35 mm x 79 mm
• Total Height: 87.80 mm
• Compression Height: 56.30 mm
• Combustion Chamber Diameter: 54.00 mm
• Combustion Chamber Depth: 23.2 mm
• Alfin Insert: Yes

Key Benefits:

• Enhanced Durability: The integrated Alfin reinforcement protects the top ring groove from premature wear under high-load conditions.
• Perfect Fitment: Manufactured to precise dimensional tolerances for seamless installation and reliable operation.
• Complete Assembly: Includes the piston, piston rings, wrist pin, and retaining clips for a comprehensive rebuild.

Cross-Reference / Interchange Part Numbers

This part replaces / is interchangeable with the following part numbers:

• 4089462
• 4089725
• 3939398
• 3969000
• 4089460
• 3939375
• 3939374