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This paper summarizes an investigation of reductions in exhaust emission levels attainable using various techniques appropriate to gasoline engines used in vehicles over 14,000 lbs GVW. Of the eight gasoline engines investigated, two were evaluated parametrically resulting in an oxidation and reduction catalyst “best combination” configuration. Four of the engines were evaluated in an EGR plus oxidation catalyst configuration, and two involved only baseline tests. Test procedures used in evaluating the six “best combination” configurations include: three engine emission test procedures using an engine dynamometer, a determination of vehicle driveability, and two vehicle emission test procedures using a chassis dynamometer. Dramatic reductions in emissions were attained with the catalyst “best combination” configurations. Engine durability, however, was not investigated.

This paper summarizes a laboratory effort toward reducing nine-mode cycle composite emissions and fuel consumption in a heavy-duty gasoline engine, while retaining current durability performance. Evaluations involved standard carburetors, a Dresserator inductor, a Bendix electronic fuel injection system, exhaust manifold thermal reactors, and exhaust gas recirculation, along with other components and engine operating parameters. A system consisting of electronic fuel injection, thermal reactors with air injection and exhaust gas recirculation, was assembled which met specified project goals. An oxidation catalyst was included as an add-on during the service accumulation demonstration. In addition, the driveability of this engine configuration was demonstrated.

This paper summarizes a laboratory effort to characterize exhaust emissions from non-catalyst and oxidation catalyst-equipped gasoline automobiles operating under malfunction conditions. One non-catalyst and four catalyst automobiles were evaluated over three test cycles in an unmodified configuration and in four engine and/or emission control system malfunction configurations. Exhaust emission constituents measured, in addition to the currently regulated automobile emissions, include: particulates, sulfates, aldehydes, sulfides, amines, metals, and several additional elements and compounds.

This paper summarizes two laboratory efforts to characterize exhaust emissions from three-way catalyst-equipped gasoline automobiles operating under malfunction conditions. Four automobiles were evaluated over three test cycles in an unmodified configuration and in four engines and/or emission control system malfunction configurations. Exhaust emission constituents measured, in addition to the currently regulated automobile emissions, include: particulates, sulfates, aldehydes, sulfides, amines, metals, and several additional elements and compounds.

This paper describes the characterization of regulated and unregulated exhaust emissions from two methanol-fueled automobiles. For comparison, two gasoline-fueled automobiles of the same make and model were also evaluated. These automobiles were evaluated over the Light-Duty Federal Test Procedure and the Highway Fuel Economy Driving Schedule. Additional evaluations with the methanol-fueled automobiles were conducted using promoted base metal catalysts, and one of these automobiles was tested in a non-catalyst configuration. Exhaust constiuents sampled for, in addition to the regulated emissions, include: aldehydes, particulate, individual hydrocarbons, methanol, ethanol, ammonia, cyanide, amines, nitrosamines, and methyl nitrite.

Methods for particulate (and associated organics) emissions control were evaluated in several diesel cars. Of the methods investigated, only “particulate traps” provided large reductions in particulate emissions. Traps evaluated included metal mesh and ceramic monolithic configurations, catalyzed and uncatalyzed. One of the cars, with a ceramic trap installed, completed fifty thousand miles of distance accumulation. No significant deterioration of emissions occurred over those fifty thousand miles.

Appropriate chassis dynamometer simulation of road power for truck tractor-trailers and buses were required for emissions evaluations. To establish such simulations, the power required to operate vehicles over a roadway (speed-power relationship) was determined for two truck tractor-trailers and one city bus. Results of these determinations, along with data reported in the literature, were used to determine the power to be absorbed by a chassis dynamometer to simulate On-road driving of trucks and buses. The chassis dynamometer is being used in the subsequent phases of this study involving emissions evaluations of heavy duty vehicles. THE PURPOSE OF THIS PAPER is to describe the findings associated with road power determination and simulation for heavy-duty trucks and buses. Included is a general discussion of road power, along with the results of evaluations on the road and on the chassis dynamometer.

This paper summarizes the results of a laboratory effort to evaluate several aspects of the use of exhaust particulate traps with heavy-duty engines. The effort involved: monitoring exhaust temperatures in heavy-duty vehicles operating on a chassis dynamometer; design and evaluation of a particulate trap bypass system; regeneration of particulate traps; and exhaust emissions evaluations of a heavy-duty diesel engine, with and without exhaust particulate traps.

A study was conducted to determine the feasibility, performance, and emissions of a Detroit Diesel Corporation 8V-71 transit bus engine using ignition-improved methanol as fuel. Major objectives to be achieved by the study were: 1) to determine the minimum amount of ignition improver required for acceptable engine operation; and 2) to compare the exhaust emissions with ignition-improver methanol to emissions with diesel fuel. The engine was tested for emissions using the transient and 13-mode emission procedures and for smoke using the Federal smoke test. In addition to measurement of regulated emissions and smoke, cylinder pressure traces were obtained and compared with pressure traces from operation on diesel fuel. Minimum modifications were made to the engine in adapting it for operation on the methanol/additive mixture.