Emission Factors for Small Utility Engines

A major gap exists in available baseline emissions data on the small utility engine population between the mid-1970's and present day. As part of the input required for a standard- setting process, the California Air Resources Board has funded limited laboratory emission measurements on a number of modern small engines, both 2-stroke and 4- stroke designs. Exhaust constituents characterized in this study include total hydrocarbons, reactive hydrocarbons (RHC), methane, CO, NOx, CO2, O2, aldehydes, and particulate matter. A total of nine engines were evaluated, spanning the range from the smallest widely- used 2-strokes (about 20 cc displacement) to 4-strokes approaching 20 hp. (A) For the covering abstract of the conference see IRRD 852385.