Parts for Detroit Diesel 371 Non-Turbo - (2 Valve Head Type) for Canada - Cylinder head Section

Parts for Detroit Diesel 3-71 Non-Turbo – (2 Valve Head Type) – Cylinder Head Section

The Detroit Diesel 3-71 engine is one of the most respected models in the legendary two-stroke Series 71 family. Known for its reliability, compact power, and long service life, it has powered everything from early marine vessels and industrial equipment to heavy trucks and stationary generators. The 3-71 uses a two-valve cylinder head design—simpler and robust—making it easier to service, rebuild, and maintain. This catalog provides everything needed for a complete top-end repair, rebuild, or replacement of the cylinder head and all associated components. Every part listed is available from Diesel Pro Power, trusted by more than 40,000 satisfied customers worldwide for genuine, rebuilt, and high-quality new Detroit Diesel parts.

Rebuilt Cylinder Heads for Detroit Diesel 3-71 (2-Valve Type)

Bare Rebuilt Cylinder Head

A bare rebuilt cylinder head for the Detroit Diesel 3-71 Non-Turbo engine offers an ideal solution for customers who wish to reuse their own valves and springs while replacing the head casting. Each unit is precision-machined, resurfaced, and pressure-tested to meet factory performance standards. The cylinder head casting is inspected for cracks, corrosion, and seat damage before rebuild. This guarantees proper compression and coolant sealing. Sold with a refundable core deposit, Diesel Pro’s rebuilt heads restore OEM performance while reducing downtime and overall costs.

Rebuilt Cylinder Head with Valves & Springs

For customers seeking a complete ready-to-install option, the rebuilt 3-71 cylinder head with valves and springs saves time and effort. Each valve seat is refaced, guides are honed to precise tolerances, and new valves, springs, retainers, and keepers are installed. The valve lash and seating are calibrated to factory specification. Like all rebuilt heads from Diesel Pro Power, it is sold with a refundable core deposit. Each head is assembled and tested by professionals familiar with Detroit Diesel’s strict quality standards, ensuring proper fitment and sealing when torqued to spec.

Both heads are compatible with Detroit Diesel 3-71 engines featuring the two-valve configuration, typically used in non-turbocharged industrial, generator, and early marine engines. The difference between a two-valve and a four-valve design lies in airflow efficiency and head geometry—the two-valve configuration emphasizes durability and simplicity.

Cylinder Head Fasteners and Related Hardware

Head Bolts

Cylinder head bolts for the Detroit Diesel 3-71 must endure extreme combustion pressures while maintaining even clamping force across the head gasket. The standard 5/8-11 x 5-3/8” head bolt is manufactured from high-strength alloy steel. Always replace head bolts if they show signs of stretching, rust, or thread wear, and torque them in sequence using the proper pattern to ensure even compression on the head gasket.

Cylinder Head Gasket Kits

Head Gasket Kit (Old Style – 2 Valve)

This gasket kit is designed specifically for the old-style 3-71 two-valve cylinder head. It includes all necessary gaskets and seals for the top end of the engine, including the head gasket, exhaust manifold gaskets, intake port seals, and other critical sealing components. Using the correct gasket kit ensures proper compression sealing, coolant flow, and exhaust performance. Diesel Pro Power’s gasket kits use premium composite materials to resist high temperature and oil exposure typical in Detroit Diesel two-stroke engines.

Rocker Cover Gasket Kits

Two main rocker cover gasket kits are available, depending on the style of your cover:

• New Style Aluminum Cover Gasket Kit: Made from durable gray rubber, this kit ensures leak-free operation on aluminum covers.

• Old Style Tin Cover Gasket Kit: Designed for tin covers and made from black rubber. This version provides a proper seal on earlier 3-71 engines and remains flexible even under heat cycling.

Both gasket types prevent oil seepage from the valve covers—a common issue in older two-stroke Detroits if gaskets become brittle or flattened over time.

Cooling System Gaskets and Plates

Water Manifold Gasket

The water manifold gasket seals the interface between the water rail and the cylinder head, ensuring proper coolant flow through the system. A leaking manifold gasket can cause coolant loss or air intrusion, both of which lead to overheating. Diesel Pro’s gasket uses reinforced materials for high-pressure sealing, ideal for both industrial and marine 3-71 engines.

Cylinder Head Water Outlet Plate

This small but critical plate covers the water outlet on the head, maintaining coolant integrity. A damaged or corroded plate can result in external leaks. The replacement plate is made from durable steel and machined to factory dimensions.

Governor and Valve Train Sealing Components

Governor Gasket

Located between the governor housing and the cylinder head, this gasket ensures a proper seal for the fuel control assembly. A leaking governor gasket can cause performance inconsistencies or oil seepage into the governor housing. Replacing this gasket during top-end service prevents contamination and maintains smooth engine response.

Rocker Cover Gaskets (Detailed)

Rocker cover gaskets prevent oil leaks around the valve mechanism area.

• Gray Rubber (New Style): Designed for aluminum rocker covers, offering heat-resistant and oil-tight sealing.

• Black Rubber (Old Style): Designed for tin rocker covers. Perfect fit for vintage or industrial 3-71 models.

Both gaskets are vital to maintaining a clean top end and preventing oil loss during extended operation.

Valve Train Components for the Detroit Diesel 3-71 Two-Valve Head

Exhaust Valve

The exhaust valve is responsible for releasing burned gases from the combustion chamber. The 30-degree valve face design provides proper seating and heat dissipation. Diesel Pro Power’s exhaust valves are built from hardened alloys to withstand high exhaust temperatures and prevent warping.

Valve Seat

The valve seat provides the sealing surface for both intake and exhaust valves. A worn seat can lead to loss of compression and poor performance. Precision-ground valve seats ensure perfect fit and sealing in rebuilt heads.

Valve Guides

Valve guides ensure the valve stem moves smoothly within the head without excessive play. Diesel Pro’s guides are manufactured to exact dimensions for Series 71 engines, minimizing oil consumption and valve chatter.

Valve Springs

Valve springs maintain valve closure under high-speed operation. Springs for the 2-valve 3-71 engine are crafted from heat-treated spring steel to prevent fatigue and maintain tension through thousands of hours of service.

Valve Seals

Valve stem seals prevent oil from entering the combustion chamber through the valve guide. The old-style design used in early 3-71 engines remains compatible with Diesel Pro’s high-quality reproductions. Maintaining proper seal integrity ensures cleaner combustion and reduces oil consumption.

Fuel and Injector Components

Injector Tubes

Injector tubes (also called fuel nozzles or sleeves) deliver pressurized fuel from the injector body into the cylinder. Diesel Pro Power offers high-quality replacements designed to fit Detroit Diesel 3-71 heads perfectly. These tubes resist corrosion and maintain precise alignment for accurate fuel atomization.

Flaring Die Tool

This Kent-Moore specialty tool is used for properly seating and flaring injector tubes during installation or reconditioning. Correct tube seating prevents leaks and ensures optimal injector spray pattern and fuel economy.

Fuel Connectors and Fittings

Detroit Diesel 3-71 engines use a series of connectors to control fuel delivery and return. Available fittings include:

• Return Connector R80 (1/4 x 5/16 NPT) for consistent return pressure.

• Restriction Connector (1/4 x 3/8 NPT) for precise flow control.

• Restriction Fittings R70 and R80 rated at 70 and 80 PSI respectively.

• Fuel Pump Elbows with various thread sizes (including 45° and 90° configurations).
  These fittings ensure the correct flow balance between injectors and the fuel return circuit.

Push Rod, Cam Follower, and Rocker Arm Components

Rocker Arm Bracket

Supports the rocker arms and maintains alignment over the valve stems. A worn bracket can lead to uneven valve lash and poor performance. Diesel Pro’s brackets are machined to OEM standards for Series 71 engines.

Rocker Arms

Available in left-hand and right-hand configurations, the rocker arms transfer motion from the cam follower to the valve. Built for durability, they feature hardened contact points to minimize wear under continuous operation.

Cam Followers

Cam followers (tappets) convert camshaft rotation into vertical motion. For the 3-71, precision ground followers maintain proper contact and reduce friction on the cam lobe. Proper lubrication and replacement at rebuild time are critical for engine longevity.

Push Rods, Springs, and Retainers

• Push Rod Springs absorb shock loads and prevent lash hammering.

• Retainers secure the rods in place.

• Spring Seats distribute spring pressure evenly to avoid wear on surrounding components.
  Together, these small parts ensure the valvetrain operates quietly and efficiently under all load conditions.

Fuel Line and Fittings Assembly

Fuel Jumper Lines (Short and Long)

The Detroit Diesel 3-71 uses alternating short and long jumper lines to connect fuel injectors. These lines must be replaced if they show corrosion or cracking. Diesel Pro Power offers both lengths, precision-flared and ready for installation.

Washer for Fuel Pipe Connector

Small copper washers that seal the connection between fuel lines and injectors. Always replace washers when disconnecting fuel lines to prevent leaks.

Nut Wrench for Fuel Line Installation

A specialized socket tool designed to install and remove Detroit Diesel injector fuel lines safely without damaging the fittings. This tool is a must-have for professional and DIY rebuilders working on 53, 71, or 92 series engines.

Cooling, Lubrication, and Accessory Components

Gasket for Water Pump

The gasket for the fresh water pump cover ensures a tight seal between the pump housing and engine block. Always replace this gasket during cooling system service to prevent leaks and maintain proper coolant pressure.

Water Manifold Stud

The manifold stud secures the water rail to the cylinder head. Corroded or stripped studs should be replaced during any head service.

Oil Filler Cap

A 2-inch oil filler cap designed for the Detroit Diesel head cover provides a secure seal for the lubrication system while allowing easy access during maintenance.

Electrical, Temperature, and Finishing Components

Temperature Switch

The temperature switch closes at approximately 205°F, providing an early warning of overheating. It can be used with auxiliary alarms or shutoff systems in marine or stationary applications.

Detroit Diesel Green Engine Paint

Authentic Detroit Diesel green paint restores the factory look of your rebuilt engine. Formulated for high-heat resistance, it resists oil, solvents, and corrosion, keeping your 3-71 looking and performing like new.

Supporting Components and Accessories

• Guides for Valve Bridges (5117564): Maintain rocker arm alignment.

• Cam Follower Guide (5106413): Keeps followers in place for consistent timing.

• Push Rod Spring Seats (Upper and Old Style): Ensures proper spring tension.

• Spring for Push Rod (5186858): Maintains compression during valve actuation.

Every small part contributes to the overall performance and reliability of the 3-71 engine. Diesel Pro Power’s parts are engineered to meet or exceed OEM standards, ensuring reliable performance whether your engine powers a vintage truck, generator, or marine vessel.

Why Choose Diesel Pro Power for Detroit Diesel 3-71 Cylinder Head Parts

Diesel Pro Power is the global leader in Detroit Diesel parts distribution, serving customers in over 180 countries. Our commitment to quality, service, and fast delivery has made us the preferred source for Series 71 rebuilders and marine engineers.

• Rebuilt heads and components tested to OEM standards

• Ready-to-ship inventory and fast worldwide delivery

• Over 40,000 satisfied customers across the globe

• Secure online ordering and responsive customer support

Whether you are restoring a classic piece of machinery, overhauling a workboat, or maintaining an industrial generator, Diesel Pro Power provides every component you need to keep your Detroit Diesel 3-71 Non-Turbo running smoothly for decades to come.