Piston Kits for Cummins QSC Engines

The Cummins QSC engine is widely used in both marine and industrial diesel applications due to its proven durability, clean combustion, and high-performance output. Whether you operate a QSC in a commercial vessel, generator, or heavy-duty machine, maintaining optimal piston and cylinder integrity is essential for long-term engine health. Diesel Pro Power proudly offers complete piston kit solutions tailored to the QSC platform.

Overview of Cummins QSC Piston Kits

Our piston kits for the Cummins QSC engine include the critical internal components required to restore compression and maintain reliable engine performance. These kits are engineered to exact Cummins specifications, matching the required dimensions, tolerances, and metallurgy standards for various QSC CPLs (Control Parts List numbers).

Each piston kit includes:

• One-piece aluminum alloy piston

• Steel piston pin (gudgeon pin)

• Full piston ring set (compression and oil control rings)

• Retainers and circlips where applicable

Compatibility by CPL Number

Diesel Pro Power offers piston kits for a wide range of QSC CPL configurations. The following CPLs are commonly supported in our available kits:
CPL 1632, 2722, 8159, 8220, 8430, 8535, 8536, 8537, 8538, 8539, 8569, 8570, 8797, 8728, 8626, 8627, 8630, 8632, 8633, 8634, 8635, 8636, 8637, 8639, 8692, 8697, 8698, 8729, 8730, 8745, 8746, 2092, 2230–2237, 2241, 2299, 2688–2694, 2698, 2964, 8088, 8153, 8203, and 8578.

If you're unsure of your engine's CPL, refer to the dataplate located on the valve cover or contact our team for assistance.

Materials and Construction

The piston components used in these kits are constructed to meet the demanding performance of Cummins QSC engines, which operate at high cylinder pressures and elevated temperatures in turbocharged configurations.

Pistons

• Material: High-strength aluminum alloy for thermal efficiency and lightweight durability.

• Design: One-piece monotherm design with optimized combustion bowl geometry for clean burn and enhanced swirl characteristics.

• Coating: Skirt coatings are included in most models to reduce friction and prevent galling during cold starts or dry operation.

Piston Pins

• Machined from hardened steel.

• Precision fit for smooth articulation within the connecting rod small-end bore.

• Designed for floating fit with circlip retainers included in each kit.

Piston Rings

• Compression Rings: High-tensile cast iron with nitrided surfaces for wear resistance.

• Oil Control Rings: Chrome-faced or multi-piece designs depending on application.

• Engineered for optimal oil scraping and sealing to reduce blow-by and oil consumption.

Cylinder Liners for Cummins QSC

Each piston operates within a precisely honed cylinder liner. Diesel Pro Power offers standard and oversized cylinder liners compatible with QSC engines, depending on the model year and sleeve configuration.

Cylinder Liner Specifications

We carry two primary variants of liners for the QSC engine family:

1. For Engines Built After 1991

• Sleeve height: 9 3/8"

• Flange diameter: 5.12” (130 mm)

• Sleeve height: 9 3/8"

• Flange diameter: 5.24” (133 mm)

• Sleeve height: 9 1/4”

• Flange diameter: 5.12” (130 mm)

All cylinder liners are manufactured to ISO standards and come fully machined with a cross-hatch finish for improved oil retention during break-in. Matching liner seals are available for all configurations.

Liner Seals

Each liner requires a rectangular profile seal (O-ring style) to ensure coolant and oil separation at the block deck.

• Material: Nitrile rubber compound engineered for thermal expansion and long-term sealing under pressure.

• One seal per liner is required.

Piston Ring Sets for QSC Engines

We offer complete piston ring sets individually for customers performing partial rebuilds or replacing damaged pistons. Each ring set contains all three rings required for one piston:

1. Top compression ring

2. Intermediate scraper ring

3. Oil control ring

Ring Materials & Features

• Nitrided, phosphate-coated, and chrome-plated options available

• Gas-nitrided rings resist scuffing in high-load environments

• Oil control rings maintain proper lubrication while preventing oil blow-by

All ring sets are compatible with OEM groove dimensions and engineered to match the specific cylinder bore diameters of QSC pistons.

When to Replace QSC Pistons

Replacing pistons and liners is a necessary step in any top-end or full engine overhaul. Key indicators that your QSC engine may need piston replacement include:

• Low compression in one or more cylinders

• Excessive oil consumption

• Piston slap or unusual knocking sounds

• Scoring or cracking observed during teardown

• Worn or collapsed piston skirts

• Excessive blow-by at the breather tube

If you notice any of the above symptoms, inspect your piston crowns and ring lands for carbon buildup, pitting, or structural damage. Replace as a complete matched set when possible to ensure balanced compression and performance.

Installation Recommendations

When installing piston kits in Cummins QSC engines, we recommend:

1. Always verify CPL compatibility before purchase.

2. Inspect connecting rod small end and crankshaft journals for scoring or ovality.

3. Use a ring compressor and piston ring gap tool to ensure correct end gap clearance.

4. Torque piston pin retainers to specification using a calibrated torque wrench.

5. Always replace liner seals and verify press fit of liner flange to prevent coolant leaks.

6. Lubricate pistons, pins, and rings with clean engine oil before assembly.

Professional installation is recommended for long-term performance and engine longevity.

Why Buy Your Cummins QSC Piston Kits from Diesel Pro Power?

• Proven Quality: Our piston kits match or exceed Cummins OEM standards for metallurgy, coating, and dimensional accuracy.

• Direct Shipping: We ship globally from our warehouse, ensuring fast turnaround and minimal downtime.

• Expert Support: Our team has decades of experience with QSC platforms and can assist with CPL lookups or kit selection.

• Trusted by 40,000+ Customers: Diesel Pro Power is the supplier of choice for commercial fleets, marine operators, and diesel professionals worldwide.

Additional QSC Engine Components Available

To complete your rebuild or maintenance project, we also carry:

• Full overhaul gasket kits

• Cylinder heads and valve train components

• Fuel injectors

• Oil pumps

• Turbochargers

• Water pumps

• Timing gears and covers

Visit our main QSC parts catalog to browse the complete product lineup.