Cummins QSC Marine Water Pump - Aftermarket

Cummins QSC Marine Water Pumps & Cooling System Components

Reliable cooling is the cornerstone of long-term performance for Cummins QSC marine engines. Whether you're operating a commercial fishing vessel, a passenger ferry, or a private yacht powered by a Cummins QSC 8.3 engine, your cooling system must perform flawlessly in harsh marine environments. Diesel Pro Power offers a comprehensive catalog of raw water pumps, impellers, gaskets, hoses, thermostats, and zincs—engineered to ensure your Cummins QSC engine stays cool, clean, and corrosion-free.

Overview of Cummins QSC Marine Cooling Systems

Cummins QSC engines, derived from the C Series platform, are known for their heavy-duty reliability and clean performance in mid-size marine applications. These engines are equipped with a gear-driven raw water pump, typically mounted with a slight offset to accommodate tight engine room geometries. In saltwater environments, this raw water pump is critical for drawing in seawater to cool the heat exchanger, oil cooler, fuel cooler, and aftercooler.

Maintaining this system with quality replacement parts is essential. Corrosion, salt scale, and impeller wear can dramatically reduce flow capacity, risking overheating or premature engine failure. At Diesel Pro Power, we stock genuine and aftermarket options to support every layer of the QSC engine cooling system—from pump to strainer to zinc plug.

Raw Water Pumps for Cummins QSC Marine Engines

Gear-Driven Marine Water Pump (C Series / QSC)

This marine water pump is built for Cummins C Series and QSC engines, including models like the 6CTA8.3-M and QSC8.3-M2. It is a gear-driven seawater pump with mounting holes offset 16° from the center shaft, designed to fit marine engine installations where clearance and access are limited.

• Durable bronze body and stainless internal hardware

• Designed for continuous duty in high-salinity environments

• Common on vessels using Cummins 6C, ISC, and QSC powerplants

Ideal for commercial vessels that demand rugged durability and long service intervals.

Bidirectional Marine Raw Water Pump (QSC / QSL / QSB Compatible)

This versatile raw seawater pump works across multiple Cummins marine engine platforms, including QSC, QSL, QSB, and legacy B and C Series. Mounting holes are 11° offset, and the pump is bidirectional, making it ideal for installations requiring clockwise or counterclockwise shaft rotation.

• Ports: 1 ¾” flange connection

• Bronze and stainless corrosion-resistant design

• Includes integrated drive gear for direct coupling to camshaft

Perfect for rebuilds or repowers requiring adaptable pump configurations.

Cummins Marine Seawater Pump for QSC & QSL (With O-Ring)

This premium seawater pump includes the mounting O-ring for leak-free installation. Designed specifically for Cummins QSC and QSL marine engines, it delivers superior flow for larger heat exchangers or aftercooler-equipped systems.

• Fully assembled and pressure tested

• Drop-in replacement for factory pump

• Reliable for both freshwater and seawater cooling loops

Impellers, Gaskets & Mounting Components

Impeller for Key Shaft – 3.5" Height

Compatible with keyway-style pump shafts, this Cummins impeller has a 3-½” height, 2-⅞” width, and 3-5/16” overall diameter. Made of marine-grade rubber compounds, it’s ideal for raw water applications with variable salinity.

• Designed for standard QSC pump housings

• Restores original flow rate

• Helps prevent overheat alarms from low seawater pressure

Marine Water Pump Gasket

The mounting gasket forms a watertight seal between the pump housing and engine timing cover. Replacing this gasket with every pump service prevents leaks and ensures proper alignment.

• Designed for 6CTA, QSC, and ISC platforms

• Sold individually; 1 required per pump

• Can be used with OEM or aftermarket pumps

Marine Pump O-Ring – Inlet/Outlet Ports

This O-ring set seals the inlet and outlet ports on Cummins QSC and QSL marine water pumps. Two required per engine. Proper sealing prevents seawater leaks that could damage engine mounts or create corrosion hotspots.

Gaskets for Heat Exchanger & Thermostat Housing

Heat Exchanger Gasket – 5" Diameter

Fits QSC, 6CTA, ISC, and L10 heat exchanger assemblies. This large-diameter gasket seals the exchanger against the water jacket and must be replaced anytime the cooler is removed for cleaning.

• 5” outer diameter

• Heat and saltwater-resistant material

• Designed for multi-year service life

Cummins Thermostat – 180 Degrees

Marine-rated thermostat opens at 180°F, ensuring rapid warm-up while preventing overheat in high-load situations. Ideal for engines operating in warm seawater or tropical climates.

• Fits QSC, ISC, ISL, and QSL engines

• Improves fuel economy during idle and partial load

• Corrosion-resistant frame and spring

Marine Impeller Pullers & Zinc Anodes

Impeller Puller – For QSC Seawater Pumps

Specifically designed for marine impellers with tight housing clearance, this impeller puller safely removes worn impellers without damaging the pump body or shaft.

• Heavy-duty marine-grade tool

• Saves time during impeller changeouts

• Works with most QSC-style pump impellers

Zinc Anode for Cummins Marine Heat Exchangers

Marine engines that use seawater cooling must be protected with sacrificial zincs. This threaded plug inserts into Cummins heat exchangers, aftercoolers, or fuel coolers.

• 1/2” NPT brass plug, 2” zinc core

• Prevents galvanic corrosion inside cooler tubes

• Replace every 6–12 months depending on salinity

Zinc for Fuel or Oil Cooler – Cummins Marine

For secondary coolers, this smaller zinc uses a 3/8” NPT thread with a 1” zinc element. Commonly used in dual-circuit fuel and oil cooling loops on QSC engines.

Marine Water Intake Strainers

Saltwater debris is a major threat to impeller life. Installing a raw water strainer protects the entire cooling circuit and minimizes pump clogging.

1" Pipe Size – Compact Marine Strainer

• Dimensions: 9½” H × 5½” W

• Ideal for low-profile installations

• Bronze or polymer construction with removable screen

1½", 2", and 2½" Pipe Size Strainers

• For higher flow applications or large vessel loops

• 16” tall housings with wide mesh baskets

• Easy disassembly for cleaning

• Secure with deck-mounting brackets or inline couplings

Silicone Coolant Hoses for QSC Engines

High-performance silicone hoses resist coolant breakdown and vibration stress common in marine engine bays. Diesel Pro Power stocks cut-to-length 1 ft. coolant hoses in sizes from 1” to 4” inside diameter.

• Ideal for coolant transfer lines, heat exchangers, and fuel cooler plumbing

• Reinforced to handle high pressure and elevated temperatures

• UV and oil-resistant outer layer

Available Sizes:

• 1", 1¾", 1⅞", 2", 2⅛", 2¼", 2½", 2⅜", 2¾", 3", 3½", 4"

Hose Clamps for Coolant & Fuel Systems

Proper hose clamping ensures leak-proof connections and prevents chafing under vibration.

• Ranges from 9/16” to 2½” diameter

• Stainless steel bands with high-torque tension

• Ideal for silicone coolant hose and fuel transfer lines

Each clamp is rated for marine use and includes rolled edges to protect hose surfaces during high-pressure operation.

Why Choose Diesel Pro Power for QSC Cooling System Components?

With over 40,000 satisfied customers worldwide, Diesel Pro Power is a trusted source for Cummins marine parts. Our QSC water pump components are stocked, inspected, and shipped from our warehouse with same-day processing on most orders.

• Detailed compatibility support for QSC, 6CTA, ISC, and QSL marine engines

• Full cooling system coverage—from pump to zinc

• Bilingual support and fast global shipping