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This paper presents test data on evaporative emissions from fuel tanks used in nonroad equipment. Measurements were made on diurnal, running loss, diffusion, and fuel tank permeation emissions. In this effort, baseline test data were collected on fuel systems that are representative of current nonroad equipment. The impacts of several test parameters on evaporative emissions were also investigated. These test parameters included temperature, fuel type, and test configuration. As temperature increased, evaporative emissions increased in all cases. In addition, blending 10 percent ethanol into the test fuel increased permeation emissions for most materials. Data are also presented on several emission control technologies. For venting emissions, the evaluation included limited flow vent paths, passively purged carbon canisters, and insulation effects. For permeation, the evaluation included surface treatments, barrier layers, and alternative materials.

Six heavy-duty diesel engines were tested for exhaust emissions on the ISO 8-mode nonroad steady-state duty cycle and the U.S. FTP highway transient test cycle. Two of these engines were baseline nonroad engines, two were Tier 1 nonroad engines, and two were highway engines. One of the Tier 1 nonroad engines and both of the highway engines were also tested on three transient cycles developed for nonroad engines. In addition, published data were collected from an additional twenty diesel engines that were tested on the 8-mode as well as at least one transient test cycle. Data showed that HC and PM emissions from diesel engines are very sensitive to transient operation while NOx emissions are much less so. Although one of the nonroad transient duty cycles showed lower PM than the steady-state duty cycles, all four of the other cycles showed much higher PM emissions than the steady-state cycle.

An inboard marine engine was tested on a dynamometer for exhaust emissions. This paper gives some insight into the characterization of baseline emissions for a new marine inboard engine as well as potential emission reductions through the use of oxygenated fuels. As the percentage of alcohol in the fuel increased, HC and CO decreased and Nox increased without a significant change in power. Fuel consumption also increased slightly. In addition, the sensitivity of the test cycle on exhaust emissions was investigated using four transient and two steady-state cycles. Only HC seemed to be affected by the amount of transience added.

A 2001 General Motors 4.3 liter V-6 marine engine was baseline emissions tested and then equipped with catalysts. Emission reduction effects of exhaust gas recirculation (EGR) were also explored. Because of a U.S. Coast Guard requirement that inboard engine surface temperatures be kept below 200°F, the engine's exhaust system, including the catalysts, was water-cooled. Engine emissions were measured using the ISO-8178-E4 5-mode steady-state test for recreational marine engines. In baseline configuration, the engine produced 16.6 g HC+NOx/kW-hr, and 111 g CO/kW-hr. In closed-loop control with catalysts, HC+NOx emissions were reduced by 75 percent to 4.1 g/kW-hr, and CO emissions were reduced by 36 percent to 70 g/kW-hr of CO. The catalyzed engine was then installed in a Sea Ray 190 boat, and tested for water reversion on both fresh and salt water using National Marine Manufacturers Association procedures.