New Ford Power Stroke for 2011 Super Duty Pickup

Ford has developed a new 6.7-liter turbocharged V8 diesel, branded “Power Stroke,” which it will be fitting into its 2011 F-Series Super Duty pickups.

Ford has developed a new 6.7-liter turbocharged V8 diesel, branded “Power Stroke,” which it will be fitting into its 2011 F-Series Super Duty pickups. This all-new engine was engineered by Ford—they used CAD and CAE extensively—tested by Ford--“This all-new diesel engine has been so extensively tested both in the lab and in the real world that we’re confident we’re giving our customers the most reliable and productive powertrain available today,” said Derrick Kuzak, Ford group vp of Global Product Development—and is being manufactured by Ford—at its Chihuahua Engine Plant.

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All of which is to say that this truly could be considered to be “Built Ford Tough.”

The engine block is made with compacted graphite iron (CGI). Ford says this is the first use of the material for a block in this class of vehicle; it has used the material for blocks that go into other types of vehicles around the world.

The thing to know about CGI: It is about twice as strong as gray cast iron, which is certainly important in diesel applications.

The cylinder heads, which feature dual water jackets, are made of aluminum. However, to help assure that they’re capable of handling firing pressures near 2,600 psi, they are each attached to the deep-skirted block with six head bolts, not four. Essentially, the cylinder heads are flipped around compared with typical V8 architectures in order to accommodate exhaust manifolds in the valley of the engine and the intake outboard. Why? The volume of the exhaust system is reduced, which (1) feeds air into the single-sequential Honeywell turbocharger more quickly for improved throttle response and (2) improves overall thermal management for better fuel efficiency (think of it as what needs to be hot is kept hot and what needs to be, well, cooler, remains so).

There is a Bosch common-rail fuel injection system that operates at pressures up to 30,000 psi that works with a unique piston design to help achieve the sort of power that Super Duty drivers expect while meeting lower emissions. The injector system can deliver up to five injection events per 6 cylinder per cycle via eight holes per piezo injector, all of which helps create a more through burn: “When the main injection occurs, we can mitigate NVH because we have a slower ignition process. When the fuel burns, it doesn’t burn with a traditional pop or bang. The direct-injection system is calibrated and phased for optimum power, fuel efficiency and NVH,” said Adam Gryglak, lead 6.7-liter diesel engineering manager (pictured). 6

To meet NOx requirements, there is a three-stage after-treatment system. First, there is the Diesel Oxidation Catalyst (DOC), that takes the exhaust that oxidizes hydrocarbons into water and CO2 at about 250°C; this heat is also used as part of thermal management for the entire exhaust system. Second, the NOx in the exhaust is transformed into water and nitrogen by Selective Catalytic Reduction (SCR). In this step, the exhaust gas is dosed with Diesel Exhaust Fluid (DEF;67.5% water; 32.5% urea). When heated, DEF becomes ammonia and CO2. So once all of this enters the SCR chamber, which has a catalyzed substrate, and is literally mixed with a corkscrew-like device and heated, the transformation occurs. The third step is for the result to be put through a Diesel Particulate Filter (DPF) where any soot is captured and eventually burned away at during occasional regeneration events, which occur at more than 600°C.