Effect of intake and exhaust valves timing on gasoline engine performance and emissions

Abstract

an internal combustion engine, valve timing is an important design parameter which affects many engine performance parameters. In this study , engine specifications were applied to the DIESEL-RK program to test engine exhaust performance and emissions and the results were there is a reduction in engine performance by de-creasing the Exhaust valve opening (EVO) angle Before bottom dead centre BBDC at all engine speeds and an increase of Oxides of Nitrogen (NOx) emissions and the effect of Exhaust valve closing (EVC) reduction is beneficial to Power, Brake Mean Effective Pressure (BMEP), and Specific Fuel Consumption (SFC) for different speed and also will reduce engine Oxides of Nitrogen (NO) and Carbon Monoxide (CO) emission down to 20° .