Ford Motor Company (Ford) has introduced a new Ford-engineered, Ford-tested and Ford-manufactured 6.7-liter Power Stroke V-8 turbocharged diesel engine. 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 new emissions requirements.
The new diesel 6.7-liter engine also shares the Super Duty’s reliability and durability while delivering 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.
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 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
– New inboard exhaust and outboard intake architecture 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 key 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 the vehicle
– Honeywell’s single-sequential turbocharger features a double-sided compressor wheel mounted on a single shaft. The unit is newly 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% biodiesel and 80% 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 productivity.”
Rugged block and 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 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 new 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 durability:
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 system.
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% biodiesel and 80% petroleum diesel. Durability cycles were run on multiple blends of diesel fuel to ensure the robustness of the system.
“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 durability engineer.
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.