Effects of Liquid LPG Injection on Combustion Stability in Spark Ignition Engine

LPG is an alternative fuel that commonly used in spark ignition engine. The research on introducing the LPG into the combustion chamber has been extended to the liquid injection rather than conventional method which is gas injection. The objective of this study specifically is to evaluate the effects of liquid LPG injection on the combustion stability as compared to the gasoline fuel. The study was conducted using 1600cc naturally aspirated engine at 2000rpm and 3000rpm at various throttle position, which were 25%, 50%, 75% and 100% of its opening. The statistical analysis has been used in determining the combustion effectiveness through peak pressure analysis from 250 continuous combustion cycle. The results were compared with the gasoline fuel for each experimental condition. The results showed that liquid LPG injection has produced better combustion stability than gasoline fuel at almost all tested conditions.