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Despite progressively stricter emission regulations, the harmful effects on the environment resulting from internal combustion engine powered vehicles. especially in heavily populated urban areas, has increased. Alternative fuels, especially neat methanol, have new found importance due to their environmental benefits. Through a research program sponsored by the U.S. Environmental Protection Agency, a direct-injected (DI) methanol glow plug engine is being developed and integrated into a passenger car. The base engine for this project is a prototype DI diesel engine, which is currently under development by Volkswagen AG. The methanol DI engine displaces 1.9L and is equipped with a turbocharger, an intercooler, and exhaust gas recirculation (EGR). The engine demonstrates basically the same favorable efficiency of a small DI diesel engine in combination with very low NOx and particulate emissions.

Potential improvements in spark ignited engine performance gained through the application of ceramic valve train components were predicted using state-of-the-art valve train simulation and gas exchange computer programs. The use of ceramic valves, ceramic pushrods, and ceramic hydraulic tappet housings, in combination with modified valve spring and valve lift parameters, were analyzed for a 2.8L overhead valve V-6 engine. The results show that significant improvements in dynamic valve train behavior and engine performance are possible with the largest gains coming from the use of ceramic valves. Potential improvements in valve train dynamics include: a 20% increase in maximum engine speed; a 30% reduction in the maximum valve train forces; and a 30% reduction in valve train friction. These benefits can then be used to either improve fuel economy, high speed engine power or low speed torque by up to 5%.

A global awareness of internal combustion engine exhaust emissions has resulted in diesel engine manufacturers considering advanced engine technologies and the use of alternative fuels, such as methanol, to address this important issue. Within this paper, the continued development of a methanol engine, based upon the Navistar DT-466 diesel engine, is outlined. A hot surface ignition (glow plug) system is used to assist in methanol ignition allowing the methanol engine to produce favorable NOx and particulate emissions, without increased unburned fuel emissions, compared to the baseline diesel version. Performance and efficiency correspond to that of the diesel engine. In addition to fuel consumption and emissions behavior, the design features of the methanol engine, such as cylinder head modifications, hot surface ignition systems and the methanol fuel injection system are presented.