The impact of compression ratio on performance and exhaust emissions in a 100 cc spark ignition engine for green technology

Abstract

The compression ratio has a significant role in vehicle performance. The arrangement of air entering and leaving the combustion chamber is determined by the design of the air inlet and outlet locations. The design of the combustion chamber is crucial to prevent backflow in the remaining combustion air. Backpressure is the emission of gases flowing back into the combustion chamber, causing non-stoichiometric combustion. The purpose of this research is to find the effect of compression ratio on performance and exhaust emissions of motorcycles, especially spark ignition engines. The research procedure begins with a standard piston modification process to get compression ratios of 9:1, 10:1, 11:1, and 12:1. In order to get uniform weight, pistons with low compression ratios will be equipped with holes at the bottom. Experimental data taken were; dynamometer, gas analyzer, and SFC. An increase in compression ratio causes an increase in vehicle performance in the form of torque and power. The air-fuel mixture is compressed to a smaller volume, leading to increased density. This increased density promotes better flame propagation and faster combustion. When the combustion process is faster and more efficient, there is less time for unburned hydrocarbons to be released into the exhaust gases.