Exhaust Emissions Characteristcs for a General Aviation Light-Aircraft Avco Lycoming TIO-540-J2BD Piston Engine.

The Avco Lycoming TIO-540-J2BD engine SN890-X was tested at the National Aviation Facilities Experimental Center NAFEC to develop a steady state exhaust emissions data base. This data base consists of current production baseline emissions characteristics, lean-out emissions data, effects of leaning-out the fuel schedule on cylinder head temperatures, and data showing ambient effects on exhaust emissions and cylinder head temperatures. The engine operating with its current full-rich production fuel schedule could not meet the proposed Environmental Protection Agency EPA standard for carbon monoxide CO and unburned hydrocarbons HC under sea level standard-day conditions. The engine did, however, meet the proposed EPA standards for oxides of nitrogen under the same sea level conditions. The results show a trend toward higher levels of emissions output for CO and HC when ambient conditions approximated hot day sea level conditions while producing slightly lower levels of NOx. Author