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This paper describes an experimental study in which the potential for fuel economy improvements with EGR was investigated using an automotive V6 engine. Steady state engine dynamometer tests were run at 2000 rpm and 200 kPa Brake Mean Effective Pressure (BMEP). The engine was fuelled with gasoline, methanol or natural gas. Plasma jet ignition was evaluated as a means of improving EGR tolerance. EGR tolerance with methanol was found to be better than with gasoline, while natural gas showed the poorest EGR tolerance. Plasma jet ignition extended EGR limits for all three fuels. Fuel economy benefits were realized with natural gas and gasoline at low EGR rates and without EGR but plasma jet ignition provided no improvements with methanol until over 10% EGR was used. Plasma jet ignition made stable operation possible with methanol at 40% EGR, where fuel economy improvements were ultimately limited by the slow burning associated with the high EGR rate.

The improvements made on a 2.0 litre indirect injection diesel engine to achieve 20 percent increase in power output and emissions lower than Bharat Stage II is presented. The improvements made are in four major areas, namely i) Auxiliary loss reduction, ii) combustion system redesign, iii) fuel injection equipment and iv) employment of after treatment devices EGR and Oxy-cat. For auxiliary loss reduction, a thermal clutch in cooling fan is introduced to increase the net power output of the engine. Combustion system improvements include increase in swirl chamber volume ratio, optimization of glow- plug protrusion in pre- chamber, redesign of depth of clover shape and introduction of piston scoop. A different injection rate profile along with Load Dependent Timer Travel and Speed dependent Timer Travel Hysterisis controls are provided in the injection pump for lower emissions.

This paper describes the vehicle implementation and cold start calibration of a neat methanol (M100) fuelled port injected engine equipped with plasma jet ignition and prompt exhaust gas recirculation. Test results are presented in which the influence of various factors on fuel enrichment requirements were studied with the aim of identifying strategies to reduce enrichment and lower start-up emissions. Vehicle cold starting has been demonstrated down to -30°C and studied in detail circa -20°C. Reductions in start-up CO emissions at -7°C have been achieved by means of early closed loop fuel control. Experimental results are also presented which indicate that the potential exists to reduce start-up hydrocarbon emissions at 25°C when appropriate calibration strategies are employed.