Cummins is one year into a four year program (ATLAS, Advanced Technology Light Automotive Systems) to develop, in partnership with the US Department of Energy (DOE), a new light-duty diesel truck engine that will meet Tier 2 Bin 2 (SULEV) emission requirements while achieving at least a 40% fuel economy improvement (26.1 mpg US vs. 18.6 mpg US, or 9.0 L/100km vs. 12.6 L/100km) over the gasoline V8 it could replace.
The ATLAS project is targeting 210 hp and 500 N·m in its fuel-efficient package.
Cummins is partnering with Nissan to fit the engine into a Nissan Titan for the demonstration of the program goals. Cummins is also partnering with Johnson Matthey Catalysts for emission controls technology in the planned aftertreatment system.
Michael Ruth, Principal Investigator for the project at Cummins, provided an update on progress at the recent 2011 DEER conference.
The baseline vehicle for comparison is a 2010 Nissan Titan, outfitted with a 5.6L all aluminum V-8 that develops 317 hp (236 kW) @ 5,200 rpm and 385 lb-ft (521 N·m) of torque @ 3,400 rpm. The baseline vehicle has a Tier 2 Bin 5 emissions rating. The ATLAS target is 210 hp (157 kW) and 500 N·m (369 lb-ft), along with the lower fuel consumption and emissions.
The design vision is to develop an engine package that will include close-coupled aftertreatment and doser for fast light off and reduced burden on OEM assembly stations; is weight-neutral to baseline gasoline powertrain; and is down-sized with high power density and minimized NVH (noise, vibration and harshness).
The new diesel engine, based on a Cummins 2.8L, inline 4-cylinder turbodiesel, is intended to be a highly integrated design to reduce the cost of installation into new applications.
The engine will leverage low-pressure EGR to reduce pumping work, and feature a fabricated exhaust manifold (rather than using cast iron). The DOC/DPF aftertreatment is assembled onto engine.
The team has completed the build of a mule engine and vehicle, with first fire in April of this year. The mule engine is currently serving as a platform for evaluating low viscosity engine oil and testing the variable swirl system. The generation 3 fuel injection system has been applied, and Cummins has designed and procured the high pressure/low pressure EGR system. Testing started 15 September.
For current accomplishments, Ruth cited elements of base engine design, including the analysis of crankshaft design including low viscosity oil properties and the power cylinder designed for short compression height and high cylinder pressure requirements. The control system logic is coupled to GT simulation, and the aftertreatment modeling is progressing. An integrated vehicle system model is under development.
SOURCE: Green Car Congress