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An emissions reduction strategy was developed and demonstrated to significantly reduce cold-start hydrocarbon (HC) and CO emissions from a spark ignition (SI), gasoline-fueled engine. This strategy involved cold-starting the engine with an ultra-fuel rich calibration, while metering near-stoichiometric fractions of air directly into the exhaust ports. Using this approach, exhaust constituents spontaneously ignited at the exhaust ports and burned into the exhaust manifold and exhaust pipe leading to the catalytic converter. The resulting exotherm accelerated catalyst heating and significantly decreased light-off time following a cold-start on the FTP-75 with a Ford Escort equipped with a 1.9L engine. Mass emissions measurements acquired during the first 70 seconds of the FTP-75 revealed total-HC and CO reductions of 68 and 50 percent, respectively, when compared to baseline measurements.

A 1993 Ford Taurus Flexible Fuel Vehicle (FFV) designed to operate on gasoline or methanol has been modified to run on Ed85 (85 vol.% denatured ethanol, 15 vol.% gasoline) and has demonstrated the ability to meet California's Ultra-Low Emissions Vehicle (ULEV) standards. The vehicle maintains the excellent driveability with potentially increased performance and similar efficiency to the baseline vehicle. Using standard twin OEM catalysts, FTP-75 emissions were 0.085 g/mi NOx, 0.88 g/mi CO, and 0.039 g/mi reactivity-adjusted NMOG. Using close-coupled catalysts upstream of the OEM catalysts, FTP-75 emissions were 0.031 g/mi NOx, 0.297 g/mi CO, and 0.015 g/mi reactivity-adjusted NMOG. The catalysts were aged to about 4,000 miles of equivalent use. These emissions compare with ULEV standards of 0.2 g/mi NOx, 1.7 g/mi CO, and 0.04 g/mi NMOG at 50,000 miles of use.

A recent study of engine sensitivity revealed that spark plugs used in conventional spark-ignited gasoline-fueled engines do not always fire in the intended fashion. Rather than firing to the ground strap during each ignition event, the arc frequently travels to the “rim” or “shell” of the spark plug. This behavior is termed rim-fire and although observed by other researchers in industry, its effects on engine performance are not widely reported. This paper addresses some of the quantitative effects of rim-fire on engine performance. Combustion data were recorded for various repeat conditions on a Ford 1.8L Zetec engine. The first set of engine tests used four, new, conventional, automotive spark plugs. The second set of engine tests used four modified spark plugs that induced 100% rim-fire when the ground strap was permanently removed. The study focused on part- and full-load engine performance, EGR tolerance, and step-transient characteristics.

A menu-driven, PC-based model, ALAMO_ENGINE, has been developed to predict the nitrogen oxides (NOx) reductions in direct-injected, diesel engines due to exhaust gas recirculation (EGR), emulsified fuels, manifold or in-cylinder water injection, fuel injection timing changes, humidity effects, and intake air temperature changes. The approach was to use a diesel engine cycle simulation with detailed gas composition calculations for the intake and exhaust gases (including EGR, water concentration, fuel-type effects, etc.), coupled with a code to calculate stoichiometric, adiabatic flame temperatures and expressions that correlate measured NOx emissions with the flame temperature. Execution times are less than 10 seconds on a 486-66 MHz PC.