Designing out emission

Researchers from Michigan Technological University developed and tested a single cylinder, four-stroke engine with electronic fuel injection and catalytic exhaust treatment for a snowmobile application.

Michigan Technological University (MTU) assembled a team of undergraduate and graduate students to compete in the 2002 Clean Snowmobile Challenge (CSC), an international, collegiate design competition administered by SAE and created to address the rising concern of pollution, both noise and emissions, from current production snowmobiles. The ultimate vehicle design strategy was separated into eight main areas, which included chassis, engine, fuel system, intake system, exhaust system, drivetrain, suspension, and track. Within each area, emphasis was placed on noise, emissions, cost, performance, and availability. Table 1 lists components used in the design of the MTU snowmobile.

There were several factors that were considered when choosing the 500-cm³, spark-ignited engine for the snowmobile, including emissions output, noise production, installation and packaging, and durability. Rated at 26 kW (35 hp), the four-stroke, single-cylinder Polaris/Fuji engine was lightweight, quiet, compact, industry approved (for ATVs), and produced lower emissions than a two-stroke engine traditionally used for snowmobiles (Figure 1).