Oversize Engine Piston Cummins 3970123 | 111753, 4089735

High-Performance Oversize Engine Piston for Cummins ISB 4.5 & QSB 4.5

Restore your engine’s compression and performance with this premium oversize (+0.50 mm) engine piston, part number 3970123. Specifically engineered for Cummins ISB 4.5 and QSB 4.5 diesel engines, this piston is manufactured to precise tolerances to withstand the extreme temperatures and pressures of heavy-duty operations. This part is also available under the numbers: 111753, 4089735.

This piston features an integrated Alfin insert for superior ring groove reinforcement, reducing wear and extending the service life of the piston. It comes complete with the piston pin and retaining clips, providing a comprehensive solution for your engine rebuild or repair needs.

Technical Specifications

• Piston Diameter: 102.50 mm (+0.50 mm oversize / STD: 102 mm)
• Combustion Chamber: 54 mm
• Piston Pin Dimensions: 34.50 mm x 79.50 mm
• Total Height: 88 mm
• Compression Height: 55.90 mm
• Alfin Insert: Yes
• Included Components: Piston body, piston pin, and retaining clips

Compatible Engine Models

• Cummins ISB 4.5
• Cummins QSB 4.5

Cross-Reference / Interchange Part Numbers

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

• 3970123
• 111753
• 4089735