Parts for Detroit Diesel 371 Non-Turbo - (4 Valve Head Type) - Engine Water Pump Section

Detroit Diesel 371 Non-Turbo (4-Valve Head Type) – Engine Water Pump Section

The Detroit Diesel 371 Non-Turbo engine remains one of the most iconic two-stroke diesels of its generation. Compact, reliable, and designed for continuous duty, this single-bank engine was the foundation for the larger 471 and 671 models that powered countless marine, industrial, and generator applications. With its 4-valve head configuration, the 371 delivered better breathing and thermal efficiency than earlier versions, but like all Detroit Diesel engines, proper cooling is essential to maintain performance and prevent premature wear.

At the heart of the engine’s cooling system lies the fresh water pump, an essential component responsible for maintaining stable coolant flow through the block, cylinder head, heat exchanger, and radiator. Whether your Detroit 371 is operating as a stationary power source, propelling a small vessel, or driving industrial equipment, Diesel Pro Power supplies every part necessary to restore, maintain, or rebuild its cooling circuit to factory reliability.

Engine Cooling Overview

The Detroit 371’s two-stroke design produces high thermal output, requiring a continuous circulation of coolant. The water pump, mounted on the front gear housing, draws coolant from the radiator or heat exchanger and pushes it through the engine block, where it absorbs heat before exiting through the thermostat housing and returning to the cooler. A properly functioning water pump ensures uniform temperature distribution across all cylinders, preventing localized overheating that could cause gasket failure or warping.

Diesel Pro Power carries complete water pump assemblies, rebuild kits, gaskets, seals, O-rings, flanges, thermostats, hoses, radiator components, and mounting accessories — all precision-engineered for the 371, 471, and 671 engine families.

Water Pump Assemblies for Detroit Diesel 371 Non-Turbo

Right-Hand Rotation Pump

The Detroit Diesel Engine Water Pump – Right-Hand Rotation is designed for engines configured with clockwise crankshaft rotation. This orientation is common in generator sets and industrial configurations. Each new pump is manufactured to exact Detroit Diesel specifications, ensuring proper impeller clearance, bearing preload, and shaft alignment for maximum flow and durability.

A new right-hand pump delivers balanced coolant pressure throughout the block, protecting cylinder liners, injector sleeves, and head gaskets from uneven heat stress. Every unit sold by Diesel Pro Power is fully assembled, pressure-tested, and ready to install — no machining or additional fitting required.

Left-Hand Rotation Pump

The Left-Hand Rotation Water Pump serves mirror-image engine installations or twin-engine marine setups where counter-rotation is needed for balanced propulsion. Precision impeller orientation and gear housing compatibility ensure reliable performance under constant load. Diesel Pro Power’s left-hand pump meets OEM performance standards and is supplied new, eliminating the need for core returns or rebuild downtime.

Water Pump Repair Kits and Components

For operators who prefer to rebuild their existing pump housing, Diesel Pro Power offers a complete Water Pump Repair Kit covering both right-hand and left-hand rotation pumps. Each kit contains high-grade bearings, shaft seals, gaskets, and impeller hardware. This allows for economical restoration of worn pumps without compromising reliability.

Proper rebuilding restores factory coolant flow rates, extends pump life, and prevents leaks at the shaft seal — a common cause of coolant contamination and bearing failure. Diesel Pro’s kits are trusted by technicians worldwide who appreciate precision-fit components that require no modification.

Gaskets, O-Rings, and Seals

A successful water pump service requires fresh sealing components. Diesel Pro Power supplies every gasket and O-ring needed for the Detroit Diesel 371’s cooling circuit:

• Pump Mounting Gasket: Forms a tight seal between the pump body and gear housing. Prevents coolant seepage and maintains internal pressure.

• Water Pump Cover Gasket: Designed for the pump’s rear access plate; resists coolant degradation and thermal cycling.

• Thermostat Housing Gasket & Thermostat Gasket: Ensure leak-free operation between the thermostat housing, head, and cover.

• O-Ring – Water Pump Outlet: Designed to withstand continuous exposure to high-temperature coolant and vibration.

• Water Seals and Manifold Seals: Used between the water manifold and oil cooler housing to prevent cross-leakage between coolant and lubrication systems.

All Diesel Pro Power gaskets and seals are made from premium materials like nitrile, silicone, or graphite composite to handle high-pressure environments typical of Detroit Diesel two-stroke engines.

Thermostats and Temperature Regulation

The Detroit Diesel 371 Thermostat opens at approximately 173°F, maintaining the correct engine temperature for optimal combustion and fuel efficiency. A properly functioning thermostat allows fast warm-up while preventing overheating under load.

Diesel Pro Power provides thermostats designed specifically for 71-series engines, calibrated for steady operation even in high ambient conditions. The thermostat’s brass construction and corrosion-resistant spring ensure consistent cycling and long life.

Accompanying each thermostat are precision-cut gaskets for leak-free installation. For fleets or operators running mixed equipment, Diesel Pro also stocks universal temperature switches that activate at 205°F for engine protection alarms or automatic shutdown systems.

Radiator, Caps, and Related Cooling Hardware

While many Detroit Diesel 371 engines use marine heat exchangers, industrial models rely on radiator-based cooling systems. Diesel Pro Power offers complete radiator assemblies, designed for heavy-duty use and built to handle the engine’s high thermal output. Each radiator provides efficient heat dissipation through reinforced cores and corrosion-resistant tanks.

Supporting hardware includes:

• Radiator Caps: Available in multiple pressure ratings, including 7-lb small-neck designs. Maintain system pressure and raise the boiling point of coolant to improve efficiency.

• Radiator Cap Necks (Small and Large): Machined precisely to fit Detroit Diesel 71-series radiators and ensure secure cap engagement.

• Drain Cocks and Fittings: Allow clean, controlled coolant drainage during service intervals.

Radiator integrity is crucial; leaks or pressure loss can reduce flow rate through the pump and lead to overheating. Diesel Pro Power’s components restore the complete cooling loop to peak condition.

Water Bypass and Thermostat Connections

The Water Bypass Tube plays a vital role in regulating coolant flow before the thermostat opens. This ensures continuous circulation and prevents localized hot spots during engine warm-up. Diesel Pro Power’s replacement bypass tube matches the original Detroit Diesel geometry, ensuring precise fit and proper coolant routing.

Made of corrosion-resistant steel or brass, these tubes maintain structural integrity even in marine environments where exposure to moisture is constant.

Silicone Coolant Hoses

To complete the cooling circuit, Diesel Pro Power supplies premium silicone coolant hoses in various diameters, from ¾ inch up to 4 inches. These hoses are reinforced with multiple plies of polyester or aramid fiber to withstand pressure and temperature extremes far beyond standard rubber hoses.

Silicone hoses offer several advantages:

• Longer lifespan under heat and vibration.

• Improved flexibility for tight bends.

• Resistance to oil mist, coolant additives, and ozone.

• Bright blue finish for easy inspection and modernized appearance.

Each hose is sold in 1-foot lengths for precise customization. They can be used for water pump connections, heat exchanger lines, and radiator inlets/outlets.

Hose Clamps

Reliable hose connections are just as critical as the hoses themselves. Diesel Pro Power carries a full range of stainless-steel hose clamps, engineered for secure sealing under varying temperature and pressure. Each clamp provides an effective diameter range suitable for the specific hose size.

• Standard Clamps: Cover 9/16" to 1-1/16" for small coolant and fuel hoses.

• Heavy-Duty Clamps: Designed for larger diameter silicone hoses up to 4".

• Precision Adjustment: Smooth inner bands prevent hose damage while ensuring even compression.

Every clamp offered by Diesel Pro Power is resistant to corrosion, vibration, and saltwater exposure — a key factor for marine or coastal industrial operations.

Temperature Switches and Monitoring Accessories

Maintaining correct operating temperature is vital for longevity. The Temperature Switch compatible with Detroit Diesel, Cummins, and Caterpillar engines activates at 205°F, providing a signal for alarms or automatic shutdowns. The ½" NPT thread size fits directly into the cylinder head or water manifold port, ensuring accurate readings.

Monitoring devices such as mechanical and electric gauges complement the temperature switch to give real-time coolant system feedback. Diesel Pro Power offers a complete range of mechanical gauges (standard and alarm-equipped) and electrical gauges for both 12-volt and 24-volt systems. These are invaluable for early detection of cooling irregularities before they escalate into costly repairs.

Radiator and System Maintenance Products

Diesel Pro Power recommends routine cooling system maintenance to preserve flow and thermal efficiency. The Radiator Cleaner available from Diesel Pro removes mineral deposits, scale, and rust that can obstruct coolant passages. Safe for copper, brass, and aluminum, it restores heat transfer performance without damaging internal components.

Because it contains no harsh acids, this cleaner is suitable for both radiator and heat-exchanger systems. Always flush with clean water before refilling with fresh coolant.

To complete the restoration, Detroit Diesel Green Engine Paint gives engines a professional finish and protects metal surfaces from corrosion. It’s formulated to match the classic Detroit Diesel shade, maintaining authentic appearance and long-term durability.

Complete Cooling System Restoration for Detroit Diesel 371 Engines

When overhauling or maintaining a Detroit Diesel 371 cooling system, a comprehensive approach ensures long-term reliability. A full service typically includes:

1. Replacing the Water Pump or Rebuilding with a Kit

• Restores coolant flow and prevents leaks.

2. Installing New Gaskets and Seals

• Eliminates coolant seepage and cross-contamination.

3. Inspecting Thermostat Functionality

• Ensures correct operating temperature and efficient combustion.

4. Cleaning or Replacing the Radiator/Heat Exchanger

• Maintains consistent cooling efficiency.

5. Fitting New Silicone Hoses and Stainless Clamps

• Enhances durability and simplifies future servicing.

6. Refilling with Proper Coolant Mixture

• Always use coolant with the correct additive package to prevent liner pitting and corrosion.

Following this sequence minimizes downtime and extends the life of critical components, from cylinder liners to injectors and seals.

Diesel Pro Power: Your Trusted Source for Detroit Diesel 371 Cooling Components

Diesel Pro Power is more than a parts supplier — it is the leading online authority for Detroit Diesel legacy engines, with over 40,000 satisfied customers worldwide. Operators from commercial fleets to private vessel owners rely on Diesel Pro’s precision-engineered components and expert service.

Why Choose Diesel Pro Power

Global Reputation: Customers in over 180 countries trust Diesel Pro for fast, reliable delivery. Each order is professionally packaged and tracked from warehouse to destination.

Premium Quality Assurance: Every pump, gasket, seal, thermostat, and accessory meets or exceeds OEM performance standards. Components are tested under load conditions comparable to real-world use.

Comprehensive Catalog Organization: Parts are indexed by engine model and system category, making it simple to locate exact matches for the Detroit Diesel 371 Non-Turbo engine.

Fast Worldwide Shipping: With strategic logistics partnerships, Diesel Pro ensures rapid delivery to ports, marinas, shipyards, and industrial sites.

Expert Technical Support: Knowledgeable specialists are available to assist with questions on pump rotation, thermostat calibration, coolant selection, or gasket compatibility.

Confidence and Longevity: Buying from Diesel Pro means investing in durable, field-tested components that extend the life of your Detroit Diesel equipment.

Maintaining Legacy Detroit Diesel Engines for the Future

The Detroit Diesel 371 is part of a legendary series that helped shape industrial power for decades. Even as technology has advanced, these engines remain valued for their simplicity, rebuildability, and rugged performance. Proper cooling maintenance ensures that this historic powerplant continues operating reliably, whether on a tugboat, generator, or vintage vehicle.

Diesel Pro Power’s commitment to supporting these legacy systems ensures that owners can continue sourcing authentic-fit components long after OEM production has ceased.

By selecting Diesel Pro Power for your Detroit Diesel 371 Non-Turbo (4-Valve Head Type) water pump, thermostat, gasket, and cooling system components, you are choosing experience, quality, and the confidence of partnering with a trusted global supplier.