Impact of Spark Ignition Timing on Pollutants of Modified Combustion Chamber of Si Engine

The most important and prominent pollutants from Spark ignition engines are carbon monoxide (CO), un-burnt hydro carbon (UBHC) and nitrogen oxide levels (NOx). Inhalation of these pollutants from atmospheric air cause serious health disorders. To control these pollutants effectively and efficiently is the need of the automobile industry. Alcohols support in reducing the pollutants as their physical properties and chemical properties are nearer to neat gasoline. Experimentation is done on four stroke variable compression engine with copper coating (300 μ , thickness) on top surface of the piston, inside of the liner and cylinder head with gasohol (20% ethanol and 80% gasoline, by vol) as fuel and with varying ignition timing and found the pollution levels of CO, UBHC and NOx. CO and UBHC are controlled with Catalytic converter and NOx levels are controlled with selective catalytic reduction (SCR) technique. Pollution levels in CCE reduced at optimum ignition timing in comparison with conventional engine with recommended ignition timing