Ford has taken the wraps off of what is quite arguably the world's most advanced turbodiesel engine, a 6.7-liter Power Stroke V8 that's due to be introduced in its redesigned 2011 F-Series Super Duty pickup trucks. Code named "Scorpion," Ford says this tech-rich oil-burner has been engineered from the start to deliver the best-in-class power, torque and fuel economy with minimal emissions. Although it has yet to issue specifics on output specs, we're told they'll handily surpass the 350-horsepower/650 lb-ft of torque churned out by the current 6.4-liter Power Stroke engine co-developed with its longstanding diesel partner, Navistar. Unlike that engine, the new Scorpion was designed and built completely in-house and also is capable of operating on up to a 20-percent biodiesel (B20) fuel blend.
At the Scorpion's core is a block made from compacted-graphite iron that's far stronger but far lighter than a normal grey cast-iron component and a state-of-the-art Bosch high-pressure common-rail direct-injection system that can deliver up to five fuel pulses per combustion cycle. Like BMW's new turbocharged 4.4-liter gasoline V8, the Scorpion's unique architecture has its exhaust valves located towards the centerline of the Vee. This layout optimizes the efficiency of the forced-induction process by permitting its ultra-compact exhaust manifolding to be positioned immediately adjacent to the turbo unit. Sourced from Honeywell, the Scorpion's "single-sequential" T-charger is an industry-exclusive design that incorporates a double-sided compressor wheel mounted on a single shaft as well as electronically controlled variable-vane geometry. This configuration allows this compact force-feeder to function in the same way as a normal smaller/larger twin-turbo setup to reduce "lag" but respond even more quickly and efficiently to throttle inputs. As a final green touch, the new 6.7-liter Power Stroke V8 is fitted with a three-stage downstream cleanup system that consists of a diesel oxidation catalyst (DOC), a selective catalytic reduction (SCR) chamber that uses a urea-based diesel exhaust fluid (DEF) to further convert oxides of nitrogen (NOx) into water and inert nitrogen, and a diesel particulate filter (DPF) that traps soot and periodically purges it by a controlled burn. The net result is that NOx levels are reduced by over 80 percent compared to current levels, to comply with more stringent federal regulations that go into effect in 2010.
Developed to exceed a 250,000-mile service life using the most rigorous durability evaluation regimen in Ford's history, the firm believes the new Scorpion turbodiesel is destined to play a key role in its future. Adam Gryglak, lead diesel engineering manager on the project notes: "After all the engineering and testing, we're confident this engine will ensure the new Super Duty continues its leadership in capability, reliability and productivity."