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Detroit Diesel 12V71 Turbo vs. Non-Turbo – Engine Specifications & Applications
Introduction
The Detroit Diesel 12V71 engine, part of the iconic Series 71 family, is a V12 two-stroke diesel engine renowned for its reliability, longevity, and flexibility. Produced in both naturally aspirated (NA) and turbocharged (T) versions, the 12V71 powered countless vessels, vehicles, and machines across the globe. These engines remain in high demand in the aftermarket due to their modularity and robust design.
At Diesel Pro Power, we support both the turbocharged and non-turbo versions of the 12V71 with a full catalog of aftermarket parts, including rebuild kits, cylinder heads, turbos, cooling systems, and more. This section breaks down the key technical specifications and real-world applications of both engine variants to help you select and support the right engine for your fleet or equipment.
Engine Specifications: 12V71 Turbo vs. Non-Turbo
Engine Architecture and Core Specs (Shared)
|
Specification |
Details |
|
Engine Type |
Two-stroke diesel |
|
Configuration |
12 cylinders in a 60° V arrangement |
|
Displacement |
852 cubic inches (13.96 liters) |
|
Bore x Stroke |
4.25 in x 5.00 in (108 mm x 127 mm) |
|
Fuel System |
Unit injector (mechanically actuated) |
|
Cooling |
Water-cooled |
|
Cylinder Heads |
6 heads (2 cylinders per head) |
|
Number of Blowers |
1 Roots-type blower (standard) |
|
Oil Capacity |
10–12 gallons |
|
Dry Weight (Base) |
~3,050–3,200 lbs |
Despite their similar internal structure, turbocharged versions use a different aspiration system and deliver significantly higher performance.
12V71 Non-Turbo (Naturally Aspirated) Specifications
|
Feature |
Value |
|
Aspiration |
Naturally aspirated (blower only) |
|
Horsepower Rating |
390–525 HP @ 2,100 RPM |
|
Peak Torque |
~1,050–1,250 lb-ft @ 1,200–1,600 RPM |
|
Turbocharger |
None |
|
Boost Pressure |
0 psi (atmospheric only) |
|
Compression Ratio |
17:1 |
|
Air Intake |
Blower-fed only |
|
Fuel Consumption (Load) |
~0.44–0.48 lb/HP/hr |
|
Operating Speed Range |
600–2,100 RPM |
|
Standard Governor |
Mechanical (variable speed) |
The naturally aspirated version of the 12V71 is often praised for its simplicity, ease of maintenance, and long service life. It’s commonly used in steady-load conditions and environments where turbocharger maintenance may be a concern.
12V71 Turbocharged Specifications
|
Feature |
Value |
|
Aspiration |
Turbocharged with blower assist |
|
Horsepower Rating |
525–650+ HP @ 2,100 RPM |
|
Peak Torque |
~1,400–1,600 lb-ft @ 1,200–1,600 RPM |
|
Turbocharger |
Single turbo, typically Garrett or Rajay |
|
Boost Pressure |
14–22 psi (varies by setup) |
|
Compression Ratio |
Slightly reduced (~16.5–17:1) |
|
Air Intake |
Turbocharger + Roots blower |
|
Fuel Consumption (Load) |
~0.42–0.46 lb/HP/hr |
|
Operating Speed Range |
600–2,300 RPM |
|
Standard Governor |
Mechanical (variable or fixed speed) |
The 12V71T (turbo) version provides a significant performance increase, especially beneficial in marine, heavy transport, and emergency equipment. It improves fuel atomization and combustion efficiency, allowing the engine to respond faster and generate more power at lower RPMs.
Key Differences at a Glance
|
Feature |
12V71 NA (Non-Turbo) |
12V71 Turbocharged |
|
Horsepower Range |
390–525 HP |
525–650+ HP |
|
Torque |
~1,050–1,250 lb-ft |
~1,400–1,600 lb-ft |
|
Turbocharger |
No |
Yes |
|
Air Supply |
Blower only |
Turbo + blower |
|
Fuel Efficiency |
Slightly lower |
Slightly better under load |
|
Parts Complexity |
Lower |
Higher (turbo system adds) |
|
Maintenance Requirement |
Simpler |
More frequent (turbo care) |
|
Response Time |
Moderate |
Faster throttle response |
|
Best Use Cases |
Low-load, steady RPM |
High-load, dynamic duty |
Why Buy Detroit Diesel 12V71 Parts From Diesel Pro Power
A Trusted Leader in Detroit Diesel Parts
Diesel Pro Power is one of the most recognized and trusted suppliers of Detroit Diesel replacement parts, serving customers around the world for decades. Their reputation is built on consistency, accuracy, and a commitment to making the parts-buying experience as simple and dependable as possible. For owners and operators of the legendary Detroit Diesel 12V71, this reliability is essential. These engines demand high-quality components to maintain peak performance, and Diesel Pro Power delivers exactly that.
Superior Parts Quality and Extensive Inventory
The 12V71 is a powerhouse used in marine, industrial, and heavy-equipment applications. Diesel Pro Power stocks a wide, carefully curated selection of components to support these engines—from cylinder kits and gaskets to cooling system parts, fuel components, and electrical hardware. Each part is engineered to meet strict quality standards, ensuring long service life and dependable performance. Their inventory is organized by engine model, making it easy to find exactly what you need without sorting through unnecessary part numbers.
World-Class Customer Support and Fast Global Shipping
Another standout advantage is Diesel Pro Power’s customer service. Their team understands Detroit Diesel engines inside and out and can help customers identify the correct components quickly and confidently. With fast shipping to 180 countries, operators can minimize downtime—whether the vessel or equipment is in a major port or a remote location.
A Company Built on Reliability
When you buy 12V71 parts from Diesel Pro Power, you’re choosing a company known for precision, expertise, and a customer-first approach. Their reliability becomes your engine’s reliability.
