EFFECT OF INJECTION PRESSURE AND TIMING ON BIODIESEL FUELLED ENGINE

An experimental matrix was designed to optimize a VW CIDI to run on biodiesel by examining the influence of injection timing only, injection pressure only and their combined influence on fuel consumption and emissions of CO, HC and NOx. Injection timing was varied at six (6) levels including advance of 9 0, 6 0, 3 0 and retardation of 6 0 and 3 0 while the engine default timing was kept at 0 0. Injection pressure was varied at five (5) levels from 150 to 250 bar in steps of 25 bar. Generally higher injection pressures produced lower fuel consumption. For PKOME and COME, an injection pressure of 250 bar and an injection advance of 30 were found with the lowest fuel consumption and least exhaust emissions. The optimal values for JCME were found to be at injection pressure of 200 bar and injection timing of 30.