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An original equipment gasoline-fueled 1999 Chevrolet Silverado pickup with a 5.3-liter, V8 engine was converted to operate on E85 (85% denatured ethanol and 15% gasoline). The simplest conversion of a gasoline-fueled vehicle to E85 requires modification to the fuel system, including use of components that are compatible with ethanol and fuel injectors that provide sufficient E85 for the stock engine control module (ECM) to effectively control engine operation. To retain the stock ECM, higher flow rate fuel injectors that provide approximately 40% more E85 than gasoline are required. With no engine modifications and similar engine control strategies, performance predictions show an approximate 7% torque and power increase for E85 over gasoline. The increase is primarily due to the specific energy differences between E85 and gasoline, although there should be a slight charge cooling benefit for E85 as a result of its higher heat of vaporization.

The instantaneous structure of a spark ignition direct injection (SIDI) engine fuel spray and the effect of injection pressure on spray structure have been investigated using flow visualization and digital particle image velocimetry (DPIV). Fuel spray experiments have been performed within a non-motored research cylinder. Instantaneous images of the fuel spray are illuminated using single Nd:YAG laser pulses (3-5 ns pulse width) formed into a sheet and passed through the fuel spray. These images are captured using a digital camera connected to an image acquisition board and computer. Flow visualization experiments for a production DI fuel injector, four injection pressures (2.1, 3.4, 4.8, and 6.2 MPa), and a 2 ms injector pulse width illustrate the evolution and instantaneous flow structure of the dense transient spray as a function of injection pressure.