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. 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. 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: 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 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. 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. 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. 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 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. 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. 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. Manifolds Elbows and connectors Mufflers Exhaust gaskets Built to handle high heat and corrosive environments. Camshafts for QSB 4.5 Camshaft bearings Valve lifters and followers Engineered for accurate timing and quiet operation under heavy use. 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. 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. 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. 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. 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. 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. We take pride in repeat customers who trust us with every repair. Our team focuses on long-term relationships, not just one-time transactions. Your data is protected with the latest encryption and security protocols. Shop with confidence, knowing your order and personal information are safe. Read real reviews from real customers who trust Diesel Pro Power for Cummins engine parts. Our service, speed, and product quality speak for themselves.
Cummins QSB 4.5 Parts
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Parts For Cummins QSB 4.5 for Marine and Industrial Engines
About the Cummins QSB 4.5 Engine
Versatile. Durable. Proven in the Field.
Applications for the Cummins QSB 4.5 Engine
Marine Applications
Industrial Applications
Full Selection of Cummins QSB 4.5 Parts
Rebuild Kits for Cummins QSB 4.5
Fresh Water Pumps for Cummins QSB 4.5
Cylinder Heads for Cummins QSB 4.5
Fuel Pumps and Fuel System Parts for Cummins QSB 4.5
Additional Engine Components and Accessories
Exhaust Systems for Cummins QSB 4.5
Camshafts for Cummins QSB 4.5Â
Switches and Sensors for Cummins QSB 4.5Â
Gauges and Instrumentation for Cummins QSB 4.5
Paints, Sealants, and Cleaners
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