Parts for Detroit Diesel 671 Turbo

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Detroit Diesel 6-71 Turbo Engine Specifications & Applications

Introduction to the Detroit Diesel 6-71 Turbocharged Engine

The Detroit Diesel 6-71 Turbo is a high-performance evolution of the time-tested 71 Series two-stroke diesel platform. With a robust inline 6-cylinder layout and the addition of a turbocharger, this engine delivers enhanced power, torque, and efficiency while retaining the rugged simplicity and modular design that define the Detroit Diesel legacy.

Widely used in marine vessels, power generation, and heavy-duty industrial equipment, the 6-71 turbocharged version provides a dependable boost in output for operations demanding more performance without stepping up to a larger engine footprint. While maintaining mechanical fuel injection and modular head design, the turbo variant allows operators to move heavier loads, climb steeper grades, or cruise at higher speeds—especially in challenging marine conditions.

At Diesel Pro Power, we offer the full spectrum of aftermarket parts for the Detroit 6-71 Turbo engine, including turbochargers, overhaul kits, fuel injectors, gaskets, cooling system parts, and more. Our parts are built to OEM-match or exceed original specs, and we ship worldwide with expert support to ensure your turbocharged 6-71 delivers power reliably for years to come.

Engine Configuration and Core Specs

Engine Series: Detroit Diesel 71 Series
Model: 6-71 Turbocharged
Cylinder Arrangement: 6-cylinder inline
Cycle: 2-Stroke Diesel
Aspiration: Turbocharged, non-intercooled (stock)
Valvetrain: Typically 4 valves per cylinder (2 intake, 2 exhaust)
Fuel System: Mechanical unit injectors (pressure-timed)
Firing Order: 1-5-3-6-2-4
Compression Ratio: ~16.5:1 (reduced to support forced induction)
Governor Options: Mechanical, variable or limiting speed

Bore, Stroke, and Displacement

Bore: 4.25 inches (108 mm)
Stroke: 5.00 inches (127 mm)
Total Displacement: 426 cubic inches (6.99 liters)

The core engine dimensions remain unchanged from the naturally aspirated 6-71, but the turbocharging system adds forced air induction to increase cylinder pressure and fuel efficiency.

Performance and Power Output

Injector Size	Approx. Horsepower @ RPM
N65	~260 HP @ 2,100 RPM
N70	~275 HP @ 2,100 RPM
N75	~290 HP @ 2,100 RPM
N80	~300+ HP @ 2,100 RPM

Typical Marine Rating: 250–300 HP
Industrial Rating: Often governed at 1,800 RPM for generators
Torque Output: 625–750 lb-ft depending on load and injector size

The turbocharger boosts power output by up to 30–40% compared to the naturally aspirated version without requiring a major increase in engine size or fuel flow under light load.

Turbocharger System Details

Turbo Type: Fixed-geometry, exhaust-driven
Mounting: Exhaust manifold-mount
Boost Pressure Range: 8–15 PSI typical
Intercooler: Not included in stock configuration (intercooler optional in retrofits)
Wastegate: Not common in stock systems

Oil and Cooling System Capacities

Oil Capacity with Filter: ~10 gallons (37.9 liters)
Coolant Capacity: ~7.5 gallons (28.4 liters)
Operating Oil Pressure: 40 – 60 PSI
Standard Operating Temp: 170°F – 195°F
Max Coolant Temp: 200°F

Turbocharged engines run hotter than non-turbo configurations, making proper cooling system maintenance and high-quality coolant components essential.

Physical Dimensions and Weight

Dry Weight: ~2,250–2,350 lbs depending on turbo and accessories
Length: ~67 inches (170 cm)
Width: ~32 inches (81 cm)
Height: ~42 inches (107 cm)

Despite the addition of a turbo system, overall size remains compact enough to fit engine rooms, machinery enclosures, and marine engine bays without major modifications.

Key Benefits of the 6-71 Turbocharged Engine

More Power with the Same Footprint

The turbocharged 6-71 offers as much as 100 more horsepower than the non-turbo 2-valve or 4-valve variants—without requiring additional displacement or engine mounts.

Improved Fuel Efficiency Under Load

Turbocharging increases the mass of air in each combustion cycle, resulting in a more complete burn of injected fuel. This means more power is produced per unit of fuel—especially during high-load operations.

Better High-Altitude and High-Heat Performance

The turbo helps compensate for air density losses at higher altitudes and ensures more consistent performance in tropical or desert climates, making it an excellent choice for global marine and industrial operators.

More Torque at Mid-Range RPMs

This is especially useful in marine towing, heavy lifting, or uphill operations, where the engine needs torque more than speed.

Marine Applications of the Detroit Diesel 6-71 Turbo Engine

Turbocharged 6-71 engines are commonly used in marine environments where horsepower, reliability, and parts availability are critical.

Commercial Use

Fishing Vessels (Crabbers, Shrimpers, Gillnetters): Delivers the torque needed to haul full nets while cruising efficiently to and from fishing grounds.
Tugboats & Push Boats: Popular in shallow-draft, harbor-assist tugboats, especially in small fleets.
Barge Pusher Boats: Capable of pushing heavier loads through inland rivers or coastal areas.
Tour and Charter Boats: Offers smoother throttle response, better economy, and higher cruise speed.
Dredgers and Support Vessels: Supports hydraulic systems and propulsion in demanding operations.

Recreational Marine Use

Large Trawlers and Liveaboard Boats: The 6-71 Turbo offers the perfect power upgrade for boaters who want better cruising speeds without sacrificing longevity.
Converted Workboats: Many ex-commercial vessels converted for private use retain their 6-71 turbo engines for their blend of power and serviceability.

Industrial and Generator Applications

The 6-71 turbocharged engine also performs reliably in land-based applications where consistent power is needed for long hours.

Prime and Standby Generators (80–125 kW): A top choice for field generators in remote oilfields, mines, and military operations.
Hydraulic Pump Systems: Used in pipeline and industrial fluid control where boost in engine output enhances flow volume.
Large Compressors: Powers drilling rig air systems and portable high-pressure compressors.
Construction Equipment: Found in older cranes, pile drivers, and rock-crushing equipment.
Mobile Utility Platforms: Trucks and trailers with PTO-driven accessories benefit from high torque at moderate RPM.

Why Choose the Turbocharged 6-71?

Boost in Performance Without Changing the Engine Block
Reliable, Proven Platform with Decades of Field Use
Still 100% Mechanically Controlled—No Electronics
Extremely Easy to Service with Widely Available Parts
Can Be Retroactively Installed in Place of NA Engines

Diesel Pro Power carries turbo kits, manifolds, and head gaskets for customers converting their naturally aspirated 6-71 engines to turbocharged configurations.