ALL-NEW FORD-ENGINEERED, FORD-TESTED, FORD-BUILT
DIESEL for 2011 SUPER DUTY
two changes that caught my eye for the 6.7L Power Stroke, an
integrated exhaust brake using the variable turbo vanes to create
back pressure and lowering the peak torque RPM to 1600 from the 2000
RPM on the 6.4L Power Stroke where diesel power should be.
Ford Press Release:
An all-new 6.7-liter Power Stroke® V-8 turbocharged
diesel engine– debuting in the 2011 Ford F-Series Super Duty® – will
deliver significant improvement in torque, horsepower and fuel
economy, enhancing productivity and further strengthening its
position as the class leader for towing and payload.
Extensive durability testing put the new Power
Stroke diesel engine through the equivalent of 250,000 miles.
Industry-first single-sequential turbocharger with double-sided
compressor wheel delivers fast throttle response along with the
volume of air boost needed for maximum power; new engine also is
biodiesel compatible up to B20.
DEARBORN, Mich., Aug. 31, 2009 – A new era in Ford
diesel technology arrives with the Ford-engineered, Ford-tested and
Ford-manufactured 6.7-liter Power Stroke V-8 turbocharged diesel
Debuting in the next-generation F-Series Super Duty
truck, the new diesel engine will deliver significant improvements
in torque, horsepower and fuel economy while adding more fueling
flexibility and easily meeting stringent new emissions requirements.
The new diesel 6.7-liter engine also shares the
Super Duty’s legendary reliability and durability while delivering
best-in-class towing and payload. “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,
group vice president of Global Product Development. “Our Super Duty
customers demand reliability and durability in their trucks so they
can deliver the best results for their business and their customers.
That’s exactly what this engine delivers.”
The diesel engine team made improvements and changes
throughout the engine architecture to deliver on aggressive
horsepower, torque, emissions and fuel economy targets. The
6.7-liter Power Stroke uses an “inboard exhaust” architecture, an
automotive-industry first for a modern production diesel engine. It
combines the best of proven technology with new, patented approaches
backed by an extensive laboratory and real-world testing regimen to
assure customer satisfaction.
Benefits of the new 6.7-liter Power Stroke V-8
turbocharged diesel engine include: First use of a compacted
graphite iron (CGI) engine block in a Super Duty-class vehicle in
North America; stronger than regular gray cast iron, Ford has
successfully used CGI in engine blocks in products around the world.
The block structure was optimized for reduced weight and maximum
strength to meet the demands of higher torque and horsepower. Unique
inboard exhaust and outboard intake architecture, an
automotive-industry first for a modern production diesel engine,
reduces overall exhaust system volume, which leads to better
throttle response for the customer; additionally, reduced exhaust
system surface area minimizes heat transfer to the engine
compartment and improves NVH (noise, vibration, harshness) The new
engine architecture enables easier service work for all major engine
components, potentially reducing down time.
On turbocharger service, for example, the body/cab
no longer has to be removed from the frame to access the turbo;
also, the high-pressure fuel pump, EGR (exhaust gas recirculation)
components and thermostats are directly accessible from the front of
Honeywell’s single-sequential turbocharger features
an industry-first double-sided compressor wheel mounted on a single
shaft. The unit is uniquely center-mounted on a pedestal low in the
back of the valley for improved NVH. This turbocharger design allows
the single unit to deliver the benefits of a twin-turbocharger
system in a smaller, more efficient package, combining 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.
The high-pressure Bosch fuel system injects fuel at
up to 30,000 psi. The system delivers up to five injection events
per cylinder per cycle using eight-hole piezo injectors to spray
fuel into the piston bowl. The direct-injection system is calibrated
and phased for optimum power, fuel efficiency and NVH.
Aluminum cylinder heads for reduced weight; the
mid-deck construction with dual water jackets provides increased
strength and optimal cooling; also, six head bolts, instead of four
as found on other engines, help improve sealing and maintain
cylinder integrity even with the higher firing pressures; overall
the engine is about 160 pounds lighter.
Compatible up to B20 fuel, allowing greener fueling
options of up to 20 percent biodiesel and 80 percent petroleum
diesel. “Our Super Duty customers are no-nonsense, no-compromise
individuals,” said Barb Samardzich, vice president, Global
Powertrain Engineering. “Those are the attributes our team took to
heart when engineering this all-new diesel engine so we can deliver
‘Built Ford Tough’ capability, reliability and enhanced
Rugged block and proven components
The capability and reliability found in the new
6.7-liter diesel engine starts with the engine block.The new Power
Stroke’s block is made from compacted graphite iron (CGI), which is
about twice as strong as regular gray cast iron. While this is the
first use of a CGI block in North America in this class of vehicle,
Ford has successfully used the material in engine blocks in other
products around the world.
“Using a CGI block is the perfect solution for the
new 6.7-liter Power Stroke,” said Adam Gryglak, lead 6.7-liter
diesel engineering manager. “It provides the strength necessary for
the increased torque and horsepower produced by our new engine, and
it also offers significant weight savings.” The diesel engine’s
deep-skirted block and main bearing caps are cross-bolted for
additional stiffness and to aid NVH. The cylinder heads mirror the
engine’s attributes as a whole, with lighter weight combined with
increased robustness: The cylinder heads are made of aluminum to
save weight and, for improved sealing, feature six head bolts per
cylinder versus the four head bolts found on other engines.
The cylinder heads, which feature dual water
jackets, are capable of firing pressures approaching 2,600 psi. The
tall water jacket works as a manifold, flowing high-velocity water
for cooling and adding to the structural robustness in the head to
handle the higher firing pressures. Crankshaft durability is
improved through Ford’s unique undercut and fillet roll treatment to
relieve stress.The valvetrain features patented dual hydraulic lash
adjustors, which improves the performance and reliability of the
valvetrain by using two pushrods per cylinder instead of the
conventional single pushrod, with individual rocker arms. Other
proven components round out the engine hardware, including
fractured-split connecting rods and a fuel system capable of
generating 30,000 psi to feed the common-rail direct-injection fuel
system. The oil pan, which bolts to the transmission, also acts as a
structural member for improved powertrain stiffness and adds to
Ford’s legacy of virtually bulletproof lower-engine architecture.
‘Built Ford Tough’ testing protocol to ensure
The testing protocol developed for the 6.7-liter
Power Stroke V-8 turbocharged diesel incorporates the most rigorous
engine tests found in Ford globally to ensure 250,000-mile
durability. Extensive CAD (computer-aided design) and CAE
(computer-aided engineering) work was completed to identify any
potential challenges before hardware was created, which not only is
time efficient but also helps ensure quality at the outset. Further,
a comprehensive examination of warranty and quality tools was used
to determine the expected failure modes for every component and
Customer data, including driving styles, road types
and vehicle usage (towing and payload), also played a key role in
developing the testing program that best replicated Super Duty use.
Components were torture-tested in the laboratory with a regimen
designed to exceed what even the harshest user might dish out.
Engines literally ran continuously for hundreds of hours. Finally, a
battery of in-vehicle, real-world tests validated the work done in
the laboratories. The strict testing work also ensured the new
engine is B20 compatible, which allows customers an environmentally
responsible fueling option of using blends up to 20 percent
biodiesel and 80 percent petroleum diesel. Durability cycles were
run on multiple blends of diesel fuel to ensure the robustness of
“These cross-functional tests give us the full
spectrum of Super Duty customers – from those who run their trucks
at maximum power with a maximum load for long periods to those who
use them more in a start-stop mode,” said Ed Waszczenko, lead engine
All-new design for all-new engine
One of the obvious visual differences in the new
6.7-liter Power Stroke V-8 turbocharged diesel engine is the layout
of the pipes. The exhaust manifolds, for example, reside in the
valley of the engine instead of outboard, while the intake is
outboard of the engine. The cylinder heads are essentially flipped
around in comparison with previous V-8 engine architectures. This
unique layout – an automotive-industry first for a modern production
diesel engine – has several advantages. First, the overall exhaust
system volume is reduced, meaning air can be fed to the single
turbocharger quicker for faster spool up and reduced lag, resulting
in improved throttle response for the customer. The improved
packaging also places components that need to be in cooler air away
from hot exhaust pipes, resulting in better thermal management and,
by extension, better fuel economy.
“The physical size of the system is smaller, but
more importantly, the air-handling part of the system is
considerably smaller and that translates directly into the
responsiveness of the engine,” said Gryglak, noting that the volume
of the exhaust system feeding the turbocharger is smaller by about
50 percent because of the inboard architecture.
Combining two turbochargers in one package
The single-sequential turbocharger – an industry
first – is key to the new diesel engine’s performance. The unit has
two compressor wheels driven off one turbine impeller. This approach
combines the benefits of a single inertia wheel – faster response
without lag – with the thrust of a larger turbocharger, with the
ability to force more compressed air into the engine for more power.
The engine’s smaller exhaust volume combined with a
corresponding smaller intake volume and smaller turbocharger creates
a system that is quicker to boost, more responsive and better able
to deliver horsepower and torque, especially at the low end, when
the customer demands it. The turbocharger includes an advanced
variable nozzle turbine, which enables variable vane pitch angles,
driving optimal turbine power to achieve optimal boosting levels for
all operating conditions.
The single shaft ensures the transition is seamless.
The unit – compact in dimensions – is uniquely center-mounted on a
patented pedestal low in the back of the valley instead of hung off
the block, which helps balance the system and aids NVH
Combustion system clean and powerful
The combustion system is the heart of the new
6.7-liter Power Stroke V-8 turbocharged diesel engine and in many
ways encapsulates the careful balancing act the Ford team achieved
in terms of power, fuel economy and reduced emissions. The key
factor in the next round of federal emissions standards, which begin
in 2010, is the reduction of oxides of nitrogen (NOx). To help
reduce NOx, the new Power Stroke burns cleaner, thanks to an
innovative way Ford developed to cool the exhaust gas recirculation
(EGR) to efficiently recycle the combustion gases in the system.
Ford’s system runs the engine with the least amount
of oxygen possible in order to reduce NOx without degrading
performance and fuel economy. Ford’s solution runs the EGR through a
two-step process utilizing separate cooling sources, something not
typically seen. The end result is the EGR is brought into the intake
at a lower temperature, which means more of it can be utilized,
creating greater efficiency throughout the system.
A unique piston bowl design and the high-pressure
fuel-injection equipment are huge enablers in achieving the balance
of power and lower emissions. The system can deliver up to five
injection events per cylinder per cycle, while eight holes in the
injector spray fuel into the bowl. The compressed-air ignition
unique to diesels is aided by pilot fuel injections before the
piston reaches the top, allowing the charge to heat up even hotter
than what you get under normal compression. “Then when the main
injection occurs, we can mitigate NVH because we have a slower
ignition process,” said Gryglak. “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.”
The new diesel engine features instant-start glow plugs, allowing
quick start even in extremely cold temperatures.
How the new Power Stroke meets new emissions
new 6.7-liter Power Stroke V-8 turbocharged diesel will employ an
aftertreatment system to help comply with 2010 federal regulations
to reduce nitrogen-oxide levels in diesel emissions by more than 80
percent compared with the previous standard. The Ford aftertreatment
system is a three-stage process; a key component is the use of
Diesel Exhaust Fluid (DEF).
Injection of DEF to reduce NOx is a proven
technology that’s been used throughout the automotive industry.
Unlike other solutions used to control NOx, the DEF system allows
the diesel engine to run at its optimum range in terms of fuel
mixture. Some systems require the engine to run richer – which can
be harmful to diesel engines – in order to control the NOx.
Step One: Cleaning and Heating – The first step
in cleaning the diesel exhaust occurs when the exhaust stream enters
the Diesel Oxidation Catalyst (DOC). The role of the DOC is twofold.
First, it converts and oxidizes hydrocarbons into water and carbon
dioxide. This conversion happens at about 250 degrees Celsius.
Second, the DOC is used to provide and promote heat, using specific
engine management strategies, into the exhaust system. Through
appropriate thermal management, this heat increases the conversion
efficiency of the downstream subsystem(s) in reducing emissions.
Step Two: Knocking Out the NOx – The next step
in the process is what’s known as Selective Catalytic Reduction (SCR).
In this process, the NOx in the exhaust stream is converted into
water and inert nitrogen, which is present in the atmosphere and
harmless. Before the exhaust gas enters the SCR chamber, it is dosed
with DEF, an aqueous solution that is approximately 67.5 percent
water and 32.5 percent pure urea. When heated, the DEF splits into
ammonia and carbon dioxide. These molecules are atomized, and
vaporized, then enter a mixer that resembles a corkscrew. This twist
mixer evenly distributes the ammonia within the exhaust flow. The
ammonia enters the SCR module, which contains a catalyzed substrate,
and through chemical reactions combines and converts the NOx and
ammonia into the harmless inert nitrogen and water. Dosing occurs
between 200 and 500 degrees Celsius.
Step Three: Scrubbing Away the Soot – The final
part of the cleansing system for the diesel exhaust gas involves the
Diesel Particulate Filter (DPF). The DPF traps any remaining soot,
which is then periodically burned away, known as regenerating, when
sensors detect the trap is full. The regeneration process sees
temperatures in excess of 600 degrees Celsius to burn away soot.
Quieter, more refined diesel sound for improved NVH
Customers of the 6.7-liter Power Stroke turbocharged
diesel engine will notice a quieter, more refined sound.
Improvements to the combustion system, structural integrity of the
compacted graphite iron block and the single turbocharger mounted to
the engine block account for many of the NVH improvements. Specific
design upgrades were made to both the piston and the piston bowl to
optimize the combustion process, which features a two-stage
combustion event instead of a single-injection event, causing harsh,
sudden and loud combustion. Instead, a starter or pilot injection of
fuel begins the compression process before the main injection.
The result is smoother combustion and a more refined
sound for the customer. When at idle, two pilot injection events are
used to make the firing process even smoother and aid in quietness.
The “ticking” of the high-speed injectors also is masked by
specially designed covers on the engine. Mounting the turbocharger
from the center housing directly to the block provided several
advantages as well in terms of NVH. “When turbochargers vibrate, it
can lead to other parts of the vehicle vibrating,” said Scott DeRaad,
engine NVH engineer. “The exhaust system, for example, is directly
attached to the turbocharger. So when the turbocharger vibrates a
lot, the exhaust system vibrates too and that’s disturbing to the
customer. Bolting the turbocharger directly to the block eliminates
Using one turbocharger, instead of two operating in
series or sequentially, helped solve some NVH challenges as well.
“Having one turbocharger eliminates the air-handling noises – the
whooshes – as the engine switches from one turbo to the next turbo,”
DeRaad said. “Our turbocharger also has ball bearings that pilot the
shaft in the turbo, which helps eliminate the potential for the
shaft of the turbocharger to gyrate in its housing, which can create
noise.” Other improvements include the addition of two resonators in
the intake system as well as a third resonator near the air cleaner.
“We’ve been able to tune the diesel intake system to
give us the sound we wanted,” DeRaad said. “It’s now a nice
complement to the engine.” The new diesel engine, which will be
built at Chihuahua Engine Plant, is the perfect complement to the
2011 Ford Super Duty, delivering both capability and reliability.
“Developing the new 6.7-liter Power Stroke V-8 turbocharged diesel
engine was an awesome endeavor,” Gryglak said. “After all the
engineering and testing, we’re confident this engine will ensure the
new Super Duty continues its leadership in capability, reliability