Parts For Cummins QSB 4.5 for Marine and Industrial Engines

The Cummins QSB 4.5 engine delivers dependable power, exceptional torque, and fuel efficiency across a wide range of heavy-duty applications. As part of Cummins' B Series, it offers a compact yet powerful design that’s ideal for marine propulsion, auxiliary power, agricultural machinery, and industrial equipment. At Diesel Pro Power, we stock and ship Cummins QSB 4.5 parts worldwide within 24 hours—supporting fast repairs, proactive maintenance, and optimized performance.

About the Cummins QSB 4.5 Engine

Versatile. Durable. Proven in the Field.

The QSB 4.5 engine is a turbocharged, aftercooled, four-cylinder diesel engine with a high-pressure common rail (HPCR) fuel system. It is based on the B Series platform and designed to meet rigorous Tier 3 and Tier 4 Final emissions standards without sacrificing performance.

Core features include:

• Displacement: 4.5 liters

• Configuration: 4-cylinder inline

• Valvetrain: 4 valves per cylinder

• Fuel System: HPCR with electronic control

• Emissions: EGR, DOC, and/or SCR systems (varies by version)

• Power Output: 110–173 HP depending on application

The QSB 4.5 is built for long hours and hard work, and is supported by Cummins' extensive service history and component interchangeability with other B Series models.

Applications for the Cummins QSB 4.5 Engine

The QSB 4.5 engine is found in a wide range of equipment where size, weight, and output must be balanced for optimal efficiency. Below are its most common use cases:

Marine Applications

• Light Commercial Vessels: Fishing boats, pilot boats, harbor tugs

• Recreational Craft: Cruisers, sport boats, sailboats

• Auxiliary Power Units (APUs): Power for shipboard systems like winches, pumps, and hydraulics

• Generators: Marine generator sets for continuous-duty and standby power

Industrial Applications

• Construction Equipment: Skid steers, compact track loaders, mobile compressors

• Agricultural Equipment: Sprayers, seeders, irrigation units, tractors

• Material Handling: Telehandlers, boom lifts, forklifts

• Stationary Equipment: Pumps, portable power units, drilling rigs, industrial generators

• Municipal Equipment: Sweepers, utility trucks, airport ground support vehicles

The engine’s compact size and high torque output at low RPMs make it ideal for marine propulsion and heavy hydraulic or PTO-driven tasks.

Full Selection of Cummins QSB 4.5 Parts

Diesel Pro Power offers a robust catalog of Cummins QSB 4.5 parts that meet or exceed OEM standards and are engineered for the demands of both marine and industrial operations.

Rebuild Kits for Cummins QSB 4.5

We offer complete and partial rebuild kits that include:

• Pistons

• Retainers

• Ring sets

• Crankshaft shell sets

• Upper and lower gasket sets

These kits are packaged for convenience and come with everything needed to perform a professional overhaul. We also stock:

• Filter removal wrenches

• Seal kits

• Piston pin bushings

• Wear ring kits

Whether you're doing preventive maintenance or a full engine tear-down, we have what you need.

Fresh Water Pumps for Cummins QSB 4.5

The cooling system plays a critical role in engine health. Our offerings include:

• Fresh water pumps (warranty-backed)

• Seal rings and gaskets

• Radiator cleaners and cooling system treatments

• Thermostat housings

These parts are built to maintain stable engine temperatures under heavy-duty workloads.

Cylinder Heads for Cummins QSB 4.5

Cylinder heads are precision-machined to OEM specs and available:

• With or without drain plugs and valves

• Valve springs and retainers

• Valve cover gaskets

• Seal kits for head reinstallation

High-quality metallurgy ensures durability and reliability even in saltwater or dusty industrial environments.

Fuel Pumps and Fuel System Parts for Cummins QSB 4.5

We supply both mechanical and electric components including:

• Primary fuel pumps

• Fuel/water separator units

• Injector gaskets

• Fuel delivery lines and clamps

Maintaining a clean and sealed fuel system is critical for power and efficiency.

Additional Engine Components and Accessories

Beyond core rebuild and fuel parts, Diesel Pro Power carries a wide selection of support components to keep your Cummins QSB 4.5 running strong.

Exhaust Systems for Cummins QSB 4.5

• Manifolds

• Elbows and connectors

• Mufflers

• Exhaust gaskets

Built to handle high heat and corrosive environments.

Camshafts for Cummins QSB 4.5 

• Camshafts for QSB 4.5

• Camshaft bearings

• Valve lifters and followers

Engineered for accurate timing and quiet operation under heavy use.

Switches and Sensors for Cummins QSB 4.5 

• Oil pressure switches

• Water temperature sensors

• Boost pressure sensors

• Marine-grade toggle switches

• Start-stop control modules

Our sensors are vibration-resistant and built to withstand harsh operational conditions.

Gauges and Instrumentation for Cummins QSB 4.5

• Oil, temp, tachometer, and voltage gauges

• Hour meters

• Waterproof gauge panels

• Control cables

Each gauge is pre-calibrated for Cummins engine specs and marine or ruggedized industrial use.

Paints, Sealants, and Cleaners

• Cummins OEM engine enamel

• Thread sealants

• Gasket adhesives

• Radiator flush and corrosion inhibitor

A fresh coat of paint and sealant helps extend the visual and mechanical life of your engine.

Why Buy Cummins QSB 4.5 Parts from Diesel Pro Power?

24-Hour Worldwide Shipping

We know downtime costs money. Our extensive inventory allows us to ship most parts anywhere in the world within 24 hours—whether you're in port or on a remote job site.

Easy-to-Use Website

Our website is fast, responsive, and organized by engine model. Quickly find what you need by category, part type, or visual identification. Designed for fleet managers and first-time DIYers alike.

Expert Customer Support

Have a question about compatibility or installation? Our support team is ready to help via phone or email. Whether you’re rebuilding an entire engine or just need a switch or gasket, we’ll walk you through it.

40,000+ Satisfied Customers

We take pride in repeat customers who trust us with every repair. Our team focuses on long-term relationships, not just one-time transactions.

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