The Ford Power Stroke Diesel Engine

The Ford Power Stroke is one of the best-selling diesel engines in America. Particularly among Super Duty truck owners, the Power Stroke diesel engine continues to be in high demand, with nearly three out of four truck owners opting for Power Stroke when purchasing a new Ford F-Series vehicle.

With superior power and reliability, the Power Stroke line of diesel engines comes top of mind when it comes to trucks that fulfill medium- to heavy-duty roles such as:

• Construction
• Ambulance use
• Snow plowing
• Farming, among others.

The Ford Power Stroke diesel engine is what runs the current line of Ford F-Series full-size pickup trucks and medium-duty trucks (from the Ford F-250 through F-550), as well as the Ford Transit, the E-series vans and cutaways, and the Low Cab Forward (LCF) commercial trucks. At one point, the Power Stroke was also used by the Ford Excursion, as well as past model year F650 / F750 vehicles.

A History of the Power Stroke Diesel Engine

The Power Stroke brand traces its origins back to 1994, mainly from a line of engines and engine improvements by Navistar International. Having gone through an extensive rebranding and numerous iterations since then, the Power Stroke engine range has been positioned as a contender against the larger-block V8 and V10 gasoline engines, specifically Dodge's Cummins B-Series inline-six and GM's Duramax V8.

In 1983, Ford started putting diesel engines in their F-series pickups and E-series vans. One of the first was the 4-stroke, 8-cylinder diesel engine by Harvester International IDI (Indirect Injection). The engine had a displacement of 420 cubic inches (6.9 L). This particular diesel engine would be naturally aspirated: it would start with compression of 20.7 to one, which would eventually go up to 21.5 to one. Its peak power was 170 horsepower and 315 foot-pounds of torque.

In 1988, Ford then offered the option to have a 444 cubic inch (7.3 L) diesel engine-- essentially similar to the earlier 6.9 L engine but with a larger bore. This would also be naturally aspirated, with peak power ratings of 185 horsepower and 338 foot-pounds of torque. A turbo version of this engine would then come out in 1993. This version did not have an intercooler, but it did have a power rating of 190 horsepower and 388 foot-pounds of torque. By 1994, these engines were already marketed under the Power Stroke brand.

What Does the Power Stroke Diesel Engine Offer in Terms of Advantages?

The Evolution of the Power Stroke Diesel Engine

Navistar International manufactured the Ford Power Stroke engines from when they were branded as such in 1994, up until 2010. In 2011, the Ford Motor Company took over the engine line’s production and has been manufacturing the Power Stroke since then. Also known as the Ford Powerstroke, the engine line uses iron and compacted graphite iron for its block material. The head material is made of aluminum and iron. The engine line uses a HEUI (hydraulically actuated electronic unit injection) Direct Injection fuel system. It also utilizes a high-pressure oil pump as well as a water-cooled liquid cooling system.

• 7.3 Powerstroke (1994 to 2003)
• 6.0 Powerstroke (2003 to 2010)
• 6.4 Powerstroke (2008 to 2010)
• 6.7 Powerstroke (2011 to present)

Depending on the engine version, power output ranges from 130 to 600 horsepower (97 to 447 kW) while torque output ranges from 350 to 935 foot-pounds (475 to 1,268 N-m).

Choate 7.3 Powerstroke Long Block

7.3 Power Stroke

The first official Power Stroke engine was Ford’s iteration of the Navistar T444E turbo-diesel V8, which was introduced as a replacement for the 7.3L IDI V8. While it was a completely reengineered design, its bore and stroke dimensions were similar to its International Harvestor predecessor. Hence, the identical (444 cubic inch/ 7.3 liter) displacement. The Power Stroke diesel engine would not be put in any Ford trucks however for from 1999 to mid-2003. While this engine build got upgraded with new turbo injectors that started coming with intercoolers, it would lose its forged connecting rods. Nevertheless, the 7.3L Power Stroke had 235 horsepower and 500 foot-pounds of torque. When it debuted, the 7.3L was an instant hit in the trucking world. During its 9-year production run, the 7.3L was widely acknowledged as a leader in diesel engine technology. Considered a legend among truckers, over two million 7.3L engine-equipped Ford Trucks are still in operation – more than Chevrolet, GMC, and Dodge diesel engines, combined.

Choate 6.0 Powerstroke Long Block

6.0 Power Stroke

The 6.0 Power Stroke diesel engine gained a bump in compression ratio-- from 17.5 to one to 18 to one. It would also gain AV GT turbo and an upgraded HEUI injection system. The power for this engine would be rated at 325 horsepower and 570 foot-pounds of torque. However, this engine is known for having reliability issues-- mainly because of the lack of head bolts; the 7.3L engine had 6 head bolts per cylinder while the 6 L engine had 4 head bolts per cylinder. Also, the bolts were torque to yield and they also gained emission systems such as an EGR system which was known to have issues and the oil cooler and fic M could also have issues in these motors. Despite the issues that the six-liter Power Stroke has experienced it is possible to make them reliable through aftermarket parts such as ARP head studs. The 6.0L was a groundbreaking engineering breakthrough during its time, giving Ford truck owners a more powerful engine yet with significantly lower emissions than its 7.3L predecessor.

Choate 6.4 Powerstroke Long Block

6.4 Power Stroke

The 6.4L (390 cubic inches) Powerstroke was the first engine introduced to the light truck market that utilized dual turbochargers from the factory. This was the first Power Stroke engine to use a DPF (diesel particulate filter) in order to nearly eliminate particulate emissions. This engine would be heavily revised, however, as it would have a common rail injection system instead of the HEUI injection system. The compound VGT turbo system it was using was rather unique for its time as most diesel engines in this category simply use a single turbo. The compression ratio for the 6.4 would also be lowered from 18 to one to 17.5 to one. It had a rating of 350 horsepower and 650 foot-pounds of torque. Despite it being a relatively strong and reliable engine, the 6.4L Powerstroke was ultimately retired after the 2010 model year, as Ford replaced it with its own in-house built 6.7L Power Stroke. Nevertheless, the 6.4L proved to be the quietest and cleanest Power Stroke engine to date, having been developed through more than 10 million miles of torturous durability testing.

Choate 6.7 Powerstroke Long Block

6.7 Power Stroke

The 6.7L Power Stroke, codenamed "Scorpion," marked a significant milestone as the first diesel engine designed and manufactured entirely by Ford. Moving away from the Navistar partnership, Ford utilized a compacted graphite iron (CGI) block to provide superior strength while reducing overall weight. A unique "reverse-flow" cylinder head design was implemented, placing the exhaust manifolds in the engine's "valley" to drive the turbocharger more efficiently and reduce heat under the hood. Since its debut, the 6.7L has undergone several updates, with its power output eventually reaching up to 500 horsepower and a massive 1,200 foot-pounds of torque in High Output versions. It is widely regarded as the most reliable and capable Power Stroke engine ever produced, successfully addressing the common failure points of its predecessors.