Fewer cylinders, more gear ratios, in-house innovation pace Ford’s 2013 powertrains
The 1.0-L triple is the first of Ford’s new Fox engine family that will see high-volume global applications. Note liquid-cooled exhaust manifold integrated with cylinder head casting.
The latest glimpse into Ford’s vehicle-propulsion offerings for 2013 and beyond shows the automaker is preparing dramatic reductions in engine displacement, cylinder count, and more transmission ratios in order to meet stringent upcoming fuel efficiency regulations. The company also is increasing its focus on in-house design, engineering, and technology development.
Included in the June 2 official unveiling of the 1.0-L three-cylinder EcoBoost engine for global applications were announcements of a new 8-speed planetary-type automatic transaxle and a new e-CVT for hybrid vehicles. The advanced transmissions are Ford in-house developments and contain a number of technical innovations.
The e-CVT is strategically significant, as it will replace Ford’s current hybrid drive currently made by Japanese supplier Aisin. It will be built at Ford’s Van Dyke transmission plant in suburban Detroit. Production starts in 4Q11 with full output slated for early 2012.
A tech-laden triple
The all-new 1.0-L is the first of Ford’s “Fox” engine family to debut. First reported by AEI in its December 2009 Powertrain online newsletter, it enters production next year at the Cologne, Germany and Craiova, Romania, engine plants. Output is slated for 2013 vehicle models based on the global B- and C-segment (Fiesta and Focus) architectures. Annual production volumes are expected to start at approximately 272,000 units, ramping up to over 1 million units by 2017, according to forecasters IHS Global Insight.
Designed at Ford’s Dunton technical center in the U.K. and currently in final calibration development, the dohc, 12-valve, direct-injected and turbocharged triple will be configured to produce SAE horsepower ratings up to 125 hp (93 kW). Future applications may include a range-extender for series-type hybrid systems, according to people familiar with the program. Its new architecture does not share internal geometries (such as bore centers and bearing diameters) with Ford’s existing Duratec inline four-cylinder range.
According to Joe Bakaj, Ford’s new Vice President of Global Powertrain Engineering, the new I3 will offer the power of a 1.6-L four with 15-20% better fuel economy and a 20-lb (9-kg) mass reduction compared with the larger engine. A Focus sedan powered by the new triple would be capable of 48 mpg on the highway.
“You’ll be surprised at its broad-flat torque curve and smooth, quiet operation,” Bakaj told a Dearborn media audience.
Isn’t a 1.0-L displacement for motorcycles? Bakaj believes customer perception of small-engine performance and fuel efficiency is changing. The old mantra of “more cubes” (and more cylinders) is no longer a primary purchase consideration, he said. As supporting evidence, Group Vice President of Global Product Development Derrick Kuzak noted that 41% of F-150 pickup sales in May were the new 3.5-L EcoBoost V6 option.
While Ford will provide further details of the new triple at the Frankfurt Motor Show in September, Bakaj noted the engine features various technologies aimed at improving thermal efficiency and reducing internal friction. Its exhaust manifold is cast integrally with the cylinder head and is liquid cooled. This helps lower exhaust-gas temperatures, allowing an optimized air-fuel ratio to be maintained over the entire rpm range.
The IEM (integral exhaust manifold) also saves approximately 2 lb (0.9 kg) compared with a separate manifold, according to Advanced Engine Design and Development Manager Brett Hinds.
“The head with the IEM and its coolant passages is a complex casting, requiring an extra core,” Hinds told AEI. “The aluminum alloy is on the higher side of cast-aluminum materials quality,” to tolerate exhaust port temperatures that can approach 1050°C, he said. “We actually had to be careful with this design, not to overcool the exhaust, to maintain sub-20-seconds catalyst light-off.”
Hinds noted that higher output versions of the new triple will have maximum cylinder pressures of 100-120 bar (1450-1740 psi), compared with 80 bar (1160 psi) on the current EcoBoost V6. The triple is being calibrated for regular-octane fuel, he said.
The Fox family cylinder blocks are designed to accommodate a single balance shaft or no shaft at all, depending on rated engine output, vehicle application, and target markets. Bakaj noted that bore diameters and bore spacing were carefully optimized so that NVH on non-balance-shaft versions is tolerable. The centerline of the triple’s 120° crankshaft is offset relative to the cylinder bore centers, reducing friction related to piston side forces by 3-5%.
The 1.0-L also features what Ford engineers call a “split cooling” thermal management system. Its key is a thermostatic bypass and oil-cooled heat exchanger that enable the cylinder block to warm up before the cylinder head during cold starts, by keeping coolant liquid in the block rather than circulating it through the radiator during initial warm-up.
“It’s a technique we developed to reduce friction caused by oil viscosity in cold ambient conditions,” he said.
As previously reported in AEI, the Fox program is Ford’s first engine program to use the automaker’s MQL “green machining” process. Proven in transmission production, the process (also called “dry machining” or MQL—Minimum Quantity Lubrication) is expected to save Ford millions in energy costs and has numerous environmental benefits.
Input-torque-sensing 8-speed
Kuzak and Bakaj had less to report regarding details of the upcoming 8-speed automatic, leaving further discussion for the Frankfurt show. Informally dubbed the “8F” by suppliers, it’s a fwd transaxle with two planetary gearsets and six clutches, designed for high torque applications. Industry sources noted that launch is targeted for Ford’s next-generation EcoBoost V6 family, code-named Nano. The new V6s will displace 2.5-2.7 L and are being planned to replace the current Duratec 35 in C/D and some larger vehicle applications.
The 8-speed is a critical enabler for downsizing the V6 by a full liter with no loss of performance, Bakaj said. It will provide up to 6% greater fuel efficiency compared with the current 6-speed automatic, through use of a longer top gear, he explained. A shorter first gear will enhance launch feel. Ratio spread of the 8-speed will be “between 7.0 and 8.0,” noted Craig Renneker, Chief Engineer for Transmission Programs.
Ford’s 8-speed announcement follows ZF’s last January that it will supply 9-speed transaxles to Chrysler beginning in MY13. Supplier insiders expect the Ford unit’s bill of materials to include up to 30% componentry shared with the 6F/6T 6-speed jointly developed with GM.
The Ford engineers provided some insight into the 8-speed’s technologies. The closed-loop clutch controls are what Renneker dubs as “next generation” and are being developed by Ford exclusively. The 8-speed’s new hydraulic actuators are integrated into the transmission case for lower tolerances and greater clutch-control precision.
The transmission also features a claimed industry-first use of an input-torque sensor, which works with the transmission control unit to match input torque to clutch pressure. The claimed result is smoother shifts and reduced “hunting” between ratios.
“Our supercomputer time in developing the new 8-speed was enormous,” Renneker said. At the media backgrounder, Kuzak, Bakaj, and Renneker all stressed the importance of increasing Ford’s Powertrain technology patent portfolio, particularly in the rapidly growing electrification space, and noted the increased focus (no pun intended) to develop technologies in-house, rather than outsource.
Lindsay Brooke
Original article available here: http://www.sae.org/mags/sve/NEWS/9890