| Manufacturer | Navistar (1994-2010) Ford Motor Company (2010-present) |
|---|---|
| Also called | Ford diesel, International Truck |
| Production | 1994-2011 |
| Predecessor | International Harvester IDI |
Power Stroke is the name given to the diesel engines found in Ford Super Duty trucks, Ford Excursion SUVs, Ford Econoline vans, and Ford LCF commercial vehicles. Production by Navistar International Corporation (International Truck and Engine Corporation) for Ford Motor Company began in mid 1994, in Indianapolis, Indiana, Huntsville, Alabama, and Brazil and continued until 2010. The Navistar sourced diesels came in displacements of 7.3, 6.9, 6.0, 4.5, and 6.4 liters. In the middle of 2010 Ford released a newly designed 6.7 Liter Powerstroke engine (codenamed the Scorpion and built in house by Ford in their Chihuahua, Mexico facility (Chihuahua Engine Plant, "CHEP") along with a newly redesigned interior and exterior and for the first time since the Powerstroke first appeared in 1994 there was no manual transmission offered. These engines primarily compete in the United States full-size pickup truck market with the Duramax V8 from General Motors/Isuzu DMAX and the B series straight 6 from Dodge/Cummins.
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The International Harvester IDI (from Indirect Injection) engine is a 4-stroke V-8 Diesel engine used in International trucks and Ford F-Series pickups from 1982 to 1994. The engine had two displacements: 420 cubic inches (6.9 litres), which was used in Ford trucks from 1983 to 1987, and 444 cubic inches (7.3 litres), which was used in Ford trucks from 1987 to 1993 (naturally aspirated). The turbo charged version was to be a single year stopgap as production of the new Power Stroke engine was to debut with the 1994 model year. (turbocharged). Production of the 7.3 Turbo IDI engine was extended to mid-year 1994 as the new engine was not ready in time for a full 1994 model year run. The turbo 7.3 was very similar to the previous 6.9l and 7.3l IDI diesel engines. They differed in that the 7.3 IDI Turbo had different wrist pins, piston rings, as well as different flow capacity fuel injectors. Additionally, the fuel injection pump output was slightly increased to compensate for the additional air charge. This engine was replaced in mid 1994 by the Navistar T444E (7.3L) engine. The 6.9 IDI, 7.3 IDI, and 7.3 IDIT engines are not in the Power Stroke family. As of 1994 during the middle of the 1994 year model production 7.3 litre Diesel and 7.3 litre Power Stroke Turbo Diesel became on option until the end of the 1994 year model production.
In mid 1994, the 7.3L Power Stroke diesel was introduced. Although the previous 7.3L had the same displacement, there weren't any other similarities between the two. The Power Stroke is an electronically controlled, direct injection engine with a 4.11 in (104 mm) bore and 4.18 in (106 mm) stroke creating a displacement of 444 cu in (7.3 L). It has a 17.5:1 compression ratio, and has a dry weight of approximately 920 lbs. This engine produced up to 250 hp (190 kW) and 505 lb·ft (685 N·m) of torque in automatic trucks during the last years of production, and 275 hp (205 kW) and 520 lb·ft (705 N·m) of torque in manual trucks. The 1994.5 to 1996/97 DI Power stroke had "single shot" HEUI (hydraulically actuated electronic unit injection) fuel injectors and ran a 15° high pressure oil pump (HPOP) to create the necessary oil pressure to fire the fuel injectors. 1994.5-1997 trucks used a cam driven fuel pump, whereas the 1999-2003 trucks used a frame rail mounted electric fuel pump. The California trucks in 1996 and 1997 had split shot fuel injectors whereas the rest of the trucks didn't get split shots until 1999. The difference between the split shot and single shot are the single shot only injects one charge of fuel per cycle, whereas the split shot releases a pre light load before the main charge to initiate combustion in a more damped manner. This controlled injection helps reduce the sharp combustion 'knock'. It utilizes a single turbocharger with a turbine housing size of 1.15 A/R. In 1999, an air to air intercooler was added to cool the charged air from the turbo making it more dense. The cooler, denser air would increase the horsepower potential of the engine, while also reducing exhaust gas temperatures (EGTs). Eventually, the turbine housing was changed to a .84 A/R housing and a wastegate was added. With larger injectors, the HPOP was advanced to 17° to change fueling characteristics. The 7.3 L DI Power Stroke was in production until the middle of model year 2003 when it was replaced by the 6.0L.
The 7.3 L (444 CID) Power Stroke was replaced by the 6.0 L (365 CID) midway through the 2003 model year. The 6.0L Power Stroke was used in Ford Super Duty trucks until the 2008 model year but lasted until 2009 in Ford Econoline vans (Model year 2010). The engine has a 3.74 in (95 mm) bore and 4.13 in (105 mm) stroke creating a displacement of 365 cu in (6.0 L) or 5954 cc. It utilizes a variable geometry turbocharger and intercooler, producing 325 hp (242 kW) and 570 lb·ft (773 N·m) with an 18:1 compression ratio, with fuel cutoff at 4200 rpm, but having a redline of 4500 rpm only attainable with aftermarket performance programming.
Some of the 6.0 L Power Stroke engines have proven to be problematic,[1] and speculated to have cost Ford millions of dollars in warranty repairs and buy backs. They led to many recalls and the repurchase of at least 500 trucks, particularly in the first year. However, aftermarket parts (e. g. redesigned EGR coolers) exist to address these issues and, with them installed, the 6.0L engine's reliability improves greatly.
Some of the problems encountered, was the possibility of the variable geometry turbo charger to stick due to carbon deposits and/or rust buildup. This could potentially cause over boost and under boost conditions, which could lead to headgasket failure. Other problems include sticking Exhaust gas recirculation valves, restricted oil coolers, which lead to leaking EGR coolers.
The major problems with the 6.0L was the torque-to-yield head bolts, which in an overboost condition would lead to a a blown head gasket, and eventually a cracked cylinder head. The 7.3 and 6.7 Power Stroke engines all have 6 head bolts per cylinder (as well as the 6.9 and 7.3 International Harvester IDI engines). By contrast, the 6.0 only has 4 head bolts per cylinder.
Numerous PCM recalibrations, fuel injector stiction along with several other driveability and QC issues have been issues for the 6.0 as well.
The 6.4 L Power Stroke replaced the 6.0 L due to new emission regulations for on-highway diesel engines built after January 1, 2007; in early 2007 Ford introduced its redesigned 2008 Super Duty with the new 6.4 liter engine as an option.
The new engine has a 3.86 in (98 mm) bore and 4.13 in (105 mm) stroke, resulting in a total calculated displacement of 387 cu in (6.3 L) or (6333 cc). Despite having to meet emission regulations, the new engine was able to increase horsepower and torque ratings to 350 hp (261 kW) and torque to 650 lb·ft (881 N·m) at the flywheel. Horsepower and torque are achieved at 3,000 rpm and 2,000 rpm respectively. It also features a dual sequential turbo system. The main components of this system are a smaller, non-wastegated turbo providing boost to a larger variable geometry turbo. This system is designed to result in reduced turbo "lag" when accelerating from a stop. The series-turbo system is set up to provide a better throttle response while in motion to give a power flow more like a Naturally aspirated engine. The 6.4 liter also has a Diesel Particulate Filter (DPF) and dual EGR coolers which are capable of reducing exhaust gas temps by up to 1000 degrees before they reach the EGR valve and mixed in with the intake charge. The Diesel Particulate filter traps soot and particulates from the exhaust and virtually eliminates the black smoke that most diesel engines expel upon acceleration. The engine computer is programmed to periodically inject extra fuel (known as a "regeneration" in F-Series) to burn off soot that accumulates in the DPF. This engine must run on Ultra Low Sulfur Diesel (ULSD) fuel which has no more than 15 ppm sulfur content; using regular diesel fuel will result in emission equipment malfunctions and violate manufacturer warranties.
The 6.4L has had one recall (Safety product recall 07S49 was released on March 23, 2007) that addresses the potential for flames to come from the tailpipe of the truck. This problem arises from the DPF which is part of the diesel after-treatment system. A PCM recalibration has been released to eliminate the possibility of excessive exhaust temperatures combined with certain rare conditions resulting from what is becoming known as a "Thermal Event".
The 6.7 L is the first medium duty diesel designed and built by Ford. It was designed in conjunction with AVL in Austria.[2] During design, Ford engineers codenamed this engine "Scorpion" due to the turbo being mounted right on top of the block.[3] It includes a Compacted graphite iron (CGI) block for greater strength while reducing weight, reverse flow aluminum cylinder heads (the exhaust ports are located in the lifter valley) with dual water jackets, six head bolts per cylinder, and 29,000 psi (1,999 bar) a high-pressure common rail Bosch fuel system. The system delivers up to five injection events per cylinder per cycle using eight-hole piezo injectors spraying fuel into the piston bowl. This engine also supports B20 biodiesel (allowing greener fueling options of up to 20 percent biodiesel and 80 percent petroleum diesel). There is also a unique inboard exhaust and outboard intake architecture, an automotive-industry first for a modern production diesel engine. Honeywell’s single-sequential turbocharger features an industry-first double-sided compressor wheel mounted on a single shaft. It combines the benefits of a small turbocharger (faster response) and a large turbocharger (ability to compress and force more air into the engine for more power) in one unit.[4] The connecting rods are made by Mahle.[5]
Emissions controls include exhaust gas recirculation, Denoxtronic based Selective Catalytic Reduction (SCR) solution from Bosch, and a Diesel Particulate Filter (DPF). Output was originally 390 hp (291 kW) and 735 lb·ft (997 N·m).[6] but shortly after production started, Ford announced that they have made an update to the new 6.7L diesel. The new engine control software makes the engine capable of 400 hp (298 kW) @ 2800 rpm and 800 lb·ft (1,085 N·m) @ 1600 rpm while achieving better fuel economy and without any physical changes to the engine. All 6.7L engines already shipped to dealerships or purchased by customers can be upgraded to Fords new specifications with a free software update available at Ford dealerships. [7]
The Power Stroke engine has been used in the following applications.
F-Series Super Duty/Excursion Applications
E-Series Applications
LCF (Low Cab Forward) Application
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