Cummins QSB 4.5 Parts - Piston Kit Section

Piston Kits for Cummins QSB 4.5 Engines

The Cummins QSB 4.5 engine is known for its reliability and performance in a wide range of industrial and marine applications. Maintaining this engine's performance requires periodic inspection and replacement of key internal components—none more critical than the pistons and related hardware.

At Diesel Pro Power, we offer complete piston kits for the Cummins QSB 4.5, tailored to a wide range of CPL numbers. Each kit is designed to restore optimal combustion, compression, and durability under constant load and variable operational demands.

One-Piece Piston Kit with Piston Pin – Compatible with CPL Groups 1982, 1995, 1989, 1998, 2048, 3602, 8529, 8530, 8781, 8782

This standard-size piston kit includes a one-piece cast aluminum piston pre-matched with a heat-treated piston pin. It's engineered for precise fit and compatibility across several QSB 4.5 applications. Each piston features reinforced crown geometry and optimized skirt coating to reduce friction and enhance wear resistance.

Kit Features:

• One-piece piston with uniform alloy composition for strength and thermal stability

• Matched piston pin included

• Direct-fit for select CPL numbers used in QSB 4.5 engines

• Ideal for mid-life rebuilds, overhauls, or top-end repairs

• Compatible with specific QSB and ISB configurations

One-Piece Piston Kit with Piston Pin – Compatible with CPL Groups 426, 427, 656, 1100, 1584, 1610, 1629, 1700, 1701, 2605, 2743, 4961, 8466, 8510, 8611, 8615, 8725, 8733, 8754, 8755, 8756

This version of the QSB 4.5 piston kit includes the same high-quality one-piece piston and matching pin but is engineered to support a wider range of CPL groups. Whether you're rebuilding for agricultural, marine, or power generation uses, this kit provides the durability and performance the QSB 4.5 platform is known for.

Kit Features:

• Aluminum piston cast as a single unit for improved strength

• Piston pin included for easy installation

• Designed for a wide range of applications using the QSB 4.5 base engine

• Provides excellent ring sealing and fuel efficiency

• Helps restore factory-rated compression levels and cylinder balance

Cylinder Liners for QSB 4.5 Engine Blocks

Cylinder liners (also referred to as sleeves) are a critical component during any piston-related overhaul. These liners provide the mating surface between piston rings and the engine block, and over time, this surface can wear, score, or crack—especially in high-load environments.

Our standard-size cylinder liner is manufactured to exact Cummins tolerances and is ready to be pressed into a properly prepared QSB 4.5 engine block. If you're rebuilding due to overheating, oil contamination, or excessive blow-by, installing fresh liners alongside piston kits is highly recommended.

Liner Features:

• Standard salvage-fit size

• Hardened surface finish for superior ring wear compatibility

• Compatible with QSB 4.5 block architecture

• Enhances oil control and compression seal

• Machined to OEM specifications for correct press fit

Piston Ring Sets for QSB 4.5 Pistons

The effectiveness of any piston rebuild comes down to the quality and fit of the piston rings. We offer multiple ring sets matched to specific piston kit styles used in the QSB 4.5. Whether you're using the piston kit compatible with CPL groups 1982–8782 or the broader 426–8756 range, we supply the correct ring set for each.

Each piston ring set includes:

• Compression rings

• Intermediate scraper rings

• Oil control rings

Ring Set for Use with CPLs 426–8756

This ring set is designed for piston kits matching the broader range of QSB 4.5 CPLs. The top and second compression rings ensure consistent combustion seal while the oil ring is precision-engineered for effective oil scraping and cylinder lubrication.

Benefits:

• Superior sealing in varied RPM ranges

• Reduced oil consumption and blow-by

• Enhanced wear resistance and heat transfer

Ring Set for Use with CPLs 1982–8782

This ring set fits pistons designed for slightly narrower CPL groups and features optimized tension profiles for applications where balance between power and fuel economy is critical.

Benefits:

• Excellent cold-start sealing

• Low-friction coating on ring faces

• Engineered for long service intervals in QSB 4.5 platforms

Choosing the Right Kit for Your QSB 4.5 Rebuild

Cummins QSB 4.5 engines can vary based on application, turbocharging, emissions setup, and CPL configuration. Matching piston kits and ring sets to your engine’s CPL is essential to prevent early failure or improper fit.

Before ordering:

• Confirm your engine’s CPL number, usually located on the dataplate

• Inspect cylinder bores for scoring or wear—liners may be required

• Check ring end gaps during installation to ensure proper clearance

• Replace piston pins if signs of oval wear are found in the connecting rod bushings

Diesel Pro Power’s inventory of QSB 4.5 rebuild components is in stock and ready to ship worldwide. Whether you're performing a complete in-frame overhaul or replacing pistons due to oil consumption or loss of compression, we have the parts you need.