Tech Briefs
The return of the HEMI
 The new HEMI engine from Chrysler is its first application of an electronic throttle control system in a rear-wheel-drive vehicle. |
Chrysler Group engineers considered as many as a dozen different engine types before determining the best vision for improving the performance parameters associated with a 5.9-L Magnum V8 that powered 2002 Dodge Ram pick-up trucks was a new HEMI, a successor to the street-legal HEMI that ended production in 1971. As powerplant for the 2003 Dodge Ram 2500 and 3500 pick-ups, the 5.7-L V8 engine with a two-valve hemispherical combustion chamber (origin of the HEMI name) produces 41% more power and 12% greater peak torque than the 56-lb (25-kg) heavier 5.9-L V8.
The HEMI also improves idle quality, fuel economy, and engine-out emissions. "We did extensive studies—more than we'd done on any other engine program—to find an alternative configuration to replace the 5.9-L V8," said Robert Lee, Director of Rear Wheel Drive Engine Engineering for the DaimlerChrysler Corp. in Auburn Hills, MI.
Engineers evaluated more than 30 characteristics—including port flow, natural frequencies, packaging, functional metrics, and injector-to-valve distance—of various engine designs. "The keys to this HEMI are the ports, the airflow, and the valve placement," said Lee.
HEMI Magnum, an internally balanced pushrod 90° V8, features a cast-iron block and aluminum alloy heads. The 5.7-L HEMI represents the Chrysler Group's first application of an electronic throttle control system in a rear-wheel-drive vehicle. For optimal control of the engine airflow, the system uses a dc motor with reduction gears to open and close the throttle.
An integrated air fuel module, supplied by Siemens VDO Automotive Corp., is housed in a seven-piece molded composite shell. "If sourced as we did on previous engine programs, there would have been 26 individual components coming from multiple suppliers," said Lee.
HEMI underwent numerous tests. For instance, more than 11.9 million customer equivalent miles (CEMs)—including 200,000 CEMs-plus durability test miles—were conducted. During a 260-h period, the HEMI was deep-shock, thermal-tested: the full throttle running engine was heated to 240°F (115°C) then hit with coolant temperatures of -20°F (-29°C).
Sixteen engines were tested to double life or beyond, and the first 1000 engines were dynamometer tested at the new Saltillo Engine Plant II in Saltillo, Mexico. Plant production capacity is 440,000 units a year.
- Kami Buchholz
Supplier pipeline to OEMs at SAE Congress
 DaimlerChrysler's Richard O. Schaum is serving as General Chairperson of the SAE 2003 World Congress. |
You're a top-tier supplier and you want to discuss your latest technologies with several potential OEM customers in just a few days. What do you do?
If you're opportunistic, you share the Cobo Center exposition floor with them at the 2003 SAE World Congress. Host company DaimlerChrysler AG and organizers of the Congress have been hard at work creating the conditions for fruitful discussion between top-tier suppliers and OEMs at the March 3-6 event in Detroit.
It was, after all, the clear consensus from the globe's top suppliers that the SAE Congress would regain its stature and value only if it provided them access to OEM decision-makers. Having gotten commitments from four major OEMs (and perhaps more in the coming months) to dramatically increase their presence at the Congress, event organizers are interested to see which supplier is first to take advantage of the opportunity.
On the show floor, DaimlerChrysler, BMW, General Motors, and Ford each will construct its own Advanced Vehicle Technology Display, where senior-level executives will be on hand to discuss the technologies with other exhibitors and visitors. While OEMs in the past have exhibited at the SAE Congress, they've never done so in such an orchestrated manner and with the specific intent of accommodating top-tier suppliers, noted Dave Amati, SAE Director of Automotive Business and the SAE World Congress Staff Team Leader.
Top-tier suppliers who put up their own exhibits at the 2003 Congress will enjoy an even more direct avenue to potential OEM customers—and again the opportunity is a result of OEMs going out of their way to give suppliers an audience. In this case, DaimlerChrysler, GM, and Ford have agreed to use meeting rooms at Cobo Center during Congress week for vehicle engineering, powertrain engineering, purchasing, and other internal, private meetings that normally would be held at the OEMs' own offices. When those private meetings adjourn, the OEM executives, engineers, and others involved will meet on the show floor with representatives from exhibiting suppliers. These OEM-supplier meetings will be prearranged.
The level of commitment among OEMs to accommodate top-tier suppliers and to support the Congress is unprecedented, said Amati. He noted that the General Chairperson of the 2003 SAE World Congress, DaimlerChrysler's Richard O. Schaum, from the outset of planning sought broad OEM support for the Congress. Amati said it is the hope of Schaum and event organizers that top-tier suppliers demonstrate the same level of commitment the OEMs have—specifically, by exhibiting.
In a further display of commitment, hundreds of executives, engineers, and other personnel from OEMs across the globe will be presenting technical papers, delivering remarks, or otherwise participating in the Congress, details of which can be found at www.sae.org/congress. Speeches and panels will be conducted on the show floor in a new Technology Theater situated near the Advanced Vehicle Technology Displays.
- Patrick Ponticel
Delphi's advanced diesel injector
  Delphi's E1 and E3 look very much alike, except for the shape of the protrusion. The picture above compares the E1 with Delphi's previous generation electronic unit injector (EUI). |
Delphi Corp.'s E1 electronic unit injector (EUI) for heavy-duty diesels has been improved through the introduction of a sophisticated "smart" version, the E3. The result of a five-year development program, the E3 uses an electronically activated nozzle control valve to allow precise shaping of injection events, leading to improved fuel economy, increased performance, and substantially reduced emissions compared with today's best production EUI, claims the company.
EUI systems integrate a pump with each injector, traditionally mounting the spill valve and control solenoid on the side of the injector body. This design provides for an effective, responsive unit, but the offset forging required makes it both bulky and complicated to manufacture. When Delphi launched the E1 in June 2000, it developed new technologies that allow the spill valve and control solenoid to be integrated within the injector body, concentric with the pump and nozzle mechanisms. Compared with the previous generation EUI, the EI used 40% fewer components while being no larger than a convention injector body.
The shorter, more direct fuel path of the E1 allows more accurate fuel metering, improved injector responsiveness, and a peak injection pressure of 200 MPa (29 ksi), up 15% compared with traditional technologies with no increase in power consumption. Elimination of the offset forging increased opportunities for improved cylinder head and valvetrain layouts and reduced the mass of each unit from 2.2 to 1.1 kg (4.9 to 2.4 lb)—resulting in a considerable saving on six- and eight-cylinder engines.
The E3 injector is built on essentially the same technology platform as the E1, though it introduces an additional valve in the injector body, just before the nozzle. Controlled by the engine-management system, this device enables very fast programmable injection events including timing and pressure. It also allows the engine- management unit to change the pressure at which the nozzle for each injection event opens, up to a maximum of 140 MPa (20 ksi).
 Delphi uses a unique laser etching process to calibrate the characteristics of both the E1 (shown) and the E3 EUIs to both increase the accuracy of fuel metering and to simplify production logistics. |
E3 is thought by Delphi to be the first EUI to provide variable injection rates, which allows optimization of combustion and hence increased performance (particularly low-speed torque) and an optimized balance between fuel economy and emissions. The system allows rising rates (increasing the fuel delivery rate through the injection event) and multiple events and provides design engineers the opportunity to introduce pilot, close-coupled pilot, main split, and late post events in addition to the main injection event.
Delphi expects an electronic unit pump (EUP) version of E3 to be available around 2004. The new version will have a separate injector for cam-in-block applications, and is being designed for diesel engines between 9 and 16 L and a 1-million km (0.6-million mi) durability. When an injector does finally need replacing, Delphi's unique laser-marking system ensures that it can be replaced individually, rather than replacing all six or eight injectors with matched units, which is required with traditional EUI technology. This feature is achieved by individually testing each injector at the Delphi factory and laser etching its performance characteristics onto the terminal block. This data is then read into the engine-management unit, providing accurate fuelling and timing characteristics for each injector. The same technique is used when the injector is initially installed in the engine at the factory, increasing the accuracy of fuel metering and simplifying production logistics.
Delphi's EUIs are manufactured in Stonehouse, UK, at a facility built specifically for EUIs and EUPs. The company uses precise machining techniques integrated with regular in-line washing and cleaning processes, cubic boron nitride grinding, and hard metal turning technologies for high-accuracy and short-manufacturing cycle times. According to the company, in-line error proofing and automatic quality check systems enable it to implement a zero-arrears/ zero-defects policy.
- Jean L. Broge
