Cummins QSM Parts - Marine Water Pump Section

Cummins QSM11 Marine Raw Water Pump & Cooling System Components

The Cummins QSM11 engine is a powerhouse in the marine industry, prized for its fuel efficiency, durability, and performance in both commercial and recreational vessels. To keep this engine running at peak performance in demanding saltwater environments, a well-maintained cooling system is absolutely essential. One of the most critical parts of that system is the marine raw water pump, often referred to as a sea water pump. At Diesel Pro Power, we carry a complete selection of marine cooling components for the QSM11, including raw water pumps, impellers, thermostats, zincs, hoses, clamps, and strainers—backed by over 40,000 satisfied customers worldwide.

Overview of the QSM11 Marine Cooling System

The Cummins QSM11 engine relies on a two-stage cooling system that separates coolant flow into fresh and raw water circuits. The raw water side draws in seawater to absorb engine heat through the heat exchanger before discharging the warmed seawater overboard. Maintaining proper function in this part of the system ensures optimal operating temperature, prevents overheating, and protects critical components such as the cylinder heads, oil cooler, and turbocharger.

At the center of the raw water system is the marine water pump. This pump is responsible for moving seawater through the heat exchanger, aftercooler, and other vital cooling circuits. Proper operation of this component—and its supporting parts—protects your investment and helps prevent costly engine damage.

Raw Water Pump for Cummins QSM11

The marine raw water pump for the QSM11 is engineered to handle high flow volumes in demanding saltwater environments. This pump is precision-cast for corrosion resistance and durability under continuous use. Designed for easy replacement and secure mounting to the front of the engine, the pump uses a shaft-driven impeller to circulate seawater through the heat exchanger loop.

Key Features

• Heavy-duty marine-grade construction

• High flow rate for optimal cooling

• Shaft-driven, spline-type connection

• Designed for long-term reliability in corrosive environments

Diesel Pro Power offers this component as a new, ready-to-install assembly. It’s a direct fit for QSM11 marine configurations and arrives fully assembled for straightforward installation.

Marine Water Pump Impeller for QSM11

The impeller is the heart of any raw water pump. On the QSM11, this rubber-vane impeller features a 14-spline shaft connection and a wide design to maximize water flow. Over time, impellers wear down or become brittle, especially in saltwater environments. A degraded impeller can drastically reduce flow and cause your engine to overheat.

Specifications

• Shaft spline type: 14 teeth

• Impeller width: 4 inches

• Outer diameter: 3 3/4 inches

• Compatible with all Cummins QSM11 raw water pump assemblies

Routine inspection and timely replacement of the impeller are critical maintenance practices for marine engines. Diesel Pro Power offers impellers designed specifically for QSM11 models to ensure reliable fit and cooling performance.

Thermostat and Thermostat Seal for QSM11

Thermostats play an essential role in regulating engine temperature. On the QSM11, the thermostat opens and closes at specific temperature ranges to optimize engine performance and fuel efficiency. Diesel Pro Power carries high-quality marine-grade thermostats and matching thermostat seals to maintain cooling system integrity.

Marine Thermostat Features

• Precise temperature control for marine applications

• Built to OEM specifications

• Reliable operation under extended loads and varying seawater temperatures

Thermostat Seal

This rubberized seal ensures a leak-free installation between the thermostat housing and engine block. Even minor seal failures can lead to coolant leaks or temperature regulation issues, making it critical to replace the seal during thermostat servicing.

Zinc Anodes for QSM11 Marine Cooling System

Marine engines operating in saltwater must use sacrificial zinc anodes to prevent galvanic corrosion. The QSM11 uses zincs in key areas such as the heat exchanger, fuel cooler, and oil cooler. These zincs corrode instead of the metallic components they protect.

Zinc Applications

• For marine heat exchanger and aftercooler

• For fuel and oil coolers

• Available in NPT 3/8" and 1/2" sizes

• Various lengths depending on component protection requirements

Routine inspection and replacement of these anodes ensure continued protection of internal cooling passages from corrosive seawater.

Marine Intake Water Strainers

Water strainers protect the raw water pump and impeller from damage caused by debris in seawater. Diesel Pro Power offers a full range of marine-grade intake strainers sized specifically for QSM11 engine installations. These components filter out seaweed, sand, and other contaminants before they can enter the engine’s cooling system.

Available Sizes

• 1" pipe size – Compact design for smaller vessels

• 1.5", 2", and 2.5" pipe sizes – Larger volume strainers for high-flow systems

• Corrosion-resistant materials

• Removable filter basket for easy cleaning

• Secure mounting for vibration resistance

Using the correct size strainer helps maintain pump performance and prolongs the lifespan of the entire cooling system.

Silicone Coolant Hoses for QSM11

Coolant hoses must withstand high pressure, temperature fluctuations, and saltwater exposure. Diesel Pro Power provides marine-grade silicone hoses for the QSM11 in multiple diameters, ensuring secure and efficient coolant flow through the engine.

Available Diameters (All 1-foot lengths)

• 1" through 4" inside diameters available

• High-temp silicone for marine environments

• Resists cracking, swelling, and saltwater corrosion

• Flexible yet durable for custom routing in tight spaces

Proper hose sizing ensures optimal flow and eliminates risk of coolant bottlenecks, which can cause localized overheating.

Hose Clamps for Marine Coolant and Fuel Hoses

In a marine engine, every hose needs a clamp that resists corrosion and maintains tight sealing over time. Diesel Pro Power carries stainless steel hose clamps tailored for coolant and fuel hoses on the Cummins QSM11.

Clamp Features

• Stainless steel construction

• Effective diameter ranges from 9/16" to 2 1/2"

• Resists loosening under vibration

• Suitable for both coolant and fuel lines

Choosing the right clamp size ensures secure hose connections and reduces the risk of leaks or hose blowouts during operation.

Importance of Routine Maintenance

Maintaining your Cummins QSM11 cooling system is key to reliable marine operation. Raw water pumps and associated components operate in a harsh environment, often under constant strain from saltwater, debris, and heat cycles. The most common causes of cooling failure—worn impellers, clogged strainers, degraded zincs, and leaking hoses—can be avoided with regular inspection and part replacement.

Recommended Maintenance Intervals

• Raw water pump inspection: Every 200–250 hours

• Impeller replacement: Annually or sooner if worn

• Zinc replacement: Every 3–6 months depending on salinity

• Thermostat replacement: Every 1–2 years

• Hose and clamp inspection: Every 6 months

By adhering to a consistent service schedule and using high-quality replacement parts, operators can extend engine life, maintain fuel efficiency, and avoid costly downtime.

Why Buy From Diesel Pro Power?

At Diesel Pro Power, we specialize in marine and industrial diesel engine components. With over 40,000 satisfied customers worldwide, we are a trusted source for Cummins QSM11 parts. All our marine water pump and cooling components are stocked and ready to ship, and our support team is ready to help you find the exact part for your engine setup.

Benefits of Ordering From Diesel Pro Power

• Worldwide shipping

• In-stock inventory for fast delivery

• Knowledgeable customer support

• Trusted by thousands of marine professionals

• Secure online checkout

Whether you're servicing a single engine or managing an entire fleet, Diesel Pro Power has the parts and expertise you need to keep your QSM11 cooling system running smoothly.