The new 6.4-liter diesel utilizes Ford Clean Diesel Technology™ to deliver the best PowerStroke® diesel ever. The new powerplant meets the most stringent emissions standards in the world, while still increasing power and torque in an engine that is smooth and quiet.

“We had to put in this level of technology to meet emissions,” said Dan Davidson, Powertrain Supervisor. “We went up in displacement to improve torque and horsepower as well. Effectively we said, ‘if we’re going to do a new engine to meet emissions, then let’s improve performance as well.’ We didn’t compromise on anything.”

The 6.4-liter PowerStroke® clean-diesel makes an impressive 350 horsepower at 3,000 rpm and 650 foot-pounds of torque starting at 2,000 rpm while reducing particulate output by up to 97 percent and posting emissions numbers on par with gasoline engines.

A tough, cast iron block and heads provide a strong, durable foundation for making power and torque. A new cylinder head design and piston bowl design optimize the high-cylinder pressures delivered by the high-pressure fuel system. The higher pressures provide more efficient combustion equating to increased power and cleaner emissions.

The pistons mount to the forged-steel crankshaft with larger, stronger rods that feature an increased rob bearing diameter. The pistons are galley-cooled providing optimized operation and increased durability.

Two turbos are better than one

The high-tech, series sequential turbochargers provide improved response throughout the entire power band with better low-end performance. Tests have shown zero-to-60 times of more than a second faster than the outgoing 6.0-liter.

The two turbochargers work in tandem. The small, electronic-controlled, smart remote variable geometry turbocharger comes on at low rpm to provide extra boost at take-off. As rpms increase, the larger fixed turbo joins the smaller turbo to boost power through the middle of the torque curve. As optimum speed is reached, the larger turbo takes over.

The system can make up to 42 pounds of boost and is bolted to the engine with mounting brackets designed to reduce NVH. The turbos themselves have been optimized against oil coking.

High-pressure fuel system makes quiet power

Clean diesel is fed to the engine via a state-of-the-art, high-pressure common rail fuel injection system. Fuel, pressurized to 26,000 PSI (1,800 bar) is injected into the cylinders through class-exclusive Piezo-electric injectors. The latest in injector technology can deliver up to five injections per combustion cycle to better control emissions, provide instant response for optimized acceleration, and improve cold start down to –20 degrees Fahrenheit.

Piezo technology is also the enabler behind the PowerStroke®’s quiet, gasoline-engine noise levels, further enhanced by mounting the injectors under the valve covers.

Innovations reduce emissions with improved fuel economy and durability

Dual 440 mm EGR coolers feature an air oxidation catalyst that literally scrubs the exhaust gasses from the air to protect coolers against fouling and the EGR valve against deposits.

The EGR valve itself is impressive. The self-cleaning valve features a high torque, high-flow, dual poppet DC electric motor that increases actuation force to 400N. The engine management system monitors the valve checking for the slight buildup that can impair the valves ability to seat securely. The module reads these “soft closings” and takes the necessary steps to clean the seat.

The Powerstroke®’s engine control module (ECM) has been improved for 2008. Fuel controls and engine controls are now integrated into the same, rugged cast aluminum housing, enabling proper operation of the state-of-the-art engine technologies. The ECM durability tests have been increased by two times to insure robustness and long life.

The highly efficient, exhaust system combines engine and emissions-control technologies such as the diesel particulate filter (DPF) and oxidation catalyst into a close-knit system, removing nearly 97 percent of the diesel particluate. The system has been optimized for performance. For example, extensive use of Computer Aided Engineering (CAE) tools optimized flow to reduce losses.

“We took a real hard focus at the minute details of the design and the angles of the transitions as you go from part to part,” said Davidson.

An all-new engine from an all-new development process

The New 6.4L diesel is more than just a clean sheet of paper engine. It benefits from an innovative clean-sheet-of-paper development process that optimized durability, performance, fuel economy and emissions.

“The Super Duty program set the precedents for this new process,” said Davidson, “and the results have been nothing short of amazing. Our initial durability test vehicles exhibited near-zero issues in reference to powertrain.”

The focus of the program was to design a development process that more accurately reflected how Super Duty customers used their vehicles everyday. The team began by collecting real-world data from working Super Duty commercial customers, tracking their daily duty cycles.

The data was used to develop durability tests that were more representative of these real-world duty cycles. For example, this was the first time that dynamometer tests were run with the transmission bolted to the engine during the durability run, allowing engineers to see how the up-shifts and downshifts affected the powertrain during the duty cycle.

The tests were conducted using the most extreme and abusive conditions and run to five-times the life cycle that the hardest-working truck would ever experience, further assuring durability,

“By the time we launch this vehicle,” said Davidson, “the engine will have seen more than 10 million equivalent miles of testing both on the dyno and in test vehicles.”

The extended testing hours allowed the team to scrutinize every component and system under theses customer-driven conditions. As a result, more than 500 design improvements were made to the diesel powertrain to improve performance and durability.

Powertrain options include the segment’s most powerful gasoline engine

The all-new 6.4-liter turbo diesel joins a proven gasoline powetrain line-up that includes the 6.8-liter, three-valve Triton™ V-10 that makes 362 horsepower and 457 pound-feet of torque – both class-leading figures.

Customers can also choose Ford’s modular 5.4-liter, three-valve Triton™ V-8 that delivers 300 horsepower and 365 pound-feet of torque. More than 80 percent of peak torque – nearly 300 pound-feet – is available starting as low as 1,000 rpm.

Both engines benefit from electronic throttle control, which provides economy and performance benefits. For commercial users who need elevated engine speed to run aftermarket power takeoff (PTO) systems, the “stationary elevated idle control” feature is available on all models.

The gasoline engines feature all-new exhaust systems and newly designed air boxes that mount solidly to the new modular front structure. Transmission choices include a six-speed manual with overdrive or a TorqShift™, Five-speed automatic. The transmissions utilize a new, unique mounting system that better isolates the powertrain and reduces vibration.

Transmissions feature all-new gear sets and a three-plate, two-stage torque converter to reduce turbine noise when the converter is locked. The F-450 uses upgraded synchronizers to enable electronic shift on the fly.

Keeping it cool increases power and durability

The Super Duty cooling system has been designed to handle the utmost of extremes. Engineers based the system tests on the F-550 chassis cab’s pulling gate of 33,000-pounds, combined weight.

“Our cooling targets are more stringent,” said Rick Murty, cooling engineer. “We shoot for lower cooling temperatures than the competition. We run the competition through our tests and their temperatures are about 30 degrees higher than ours. That 30 degrees of cooling turns into more towing power and more torque.”

Super Duty’s radiator has grown by 33 percent and a larger water pump nearly doubles flow rate from 75 to 140 gals per minute.

A larger fuel filter better separates water from the fuel, an important asset with the onset of biodiesel. Ford recommends B5 (5 percent biodiesel) for Super Duty’s 6.4-liter PowerStroke turbo Diesel.