Field-Testing of Biodiesel (B100) and Diesel-Fueled Vehicles: Part 4—Piston Rating, and Fuel Injection Equipment Issues

Abstract

This study investigated use of biodiesel (B100) and baseline diesel in two identical unmodified vehicles to realistically assess different aspects of biodiesel's compatibility with modern common rail direct injection (CRDI) system and evaluate biodiesel's long-term durability/ compatibility with engine components. The fourth paper of this series compares the effects of long-term usage of biodiesel on piston deposits, and fuel injection equipment (FIE) compared to baseline mineral diesel. Key challenge for improving engine performance and fuel economy is reduction of frictional losses, primarily at the piston ring-liner interface, which accounts for major part of the total frictional losses. Piston rating was done for the two vehicles after the conclusion of field-trials and it revealed that rating of different piston sections was ~5-15% superior for biodiesel fueled vehicle compared to diesel fueled vehicle. In biodiesel fueled vehicle, peculiar white piston deposits were observed, which were absent in diesel fueled vehicle. Performance of FIE components such as fuel filters, fuel injectors, and fuel pumps was assessed after the conclusion of field-trails. Pressure drop at different fuel flow rates across the fuel filter were measured for assessing fuel filter blockage. Pressure drop across biodiesel fuel filter was ~30% higher than diesel fuel filter after 10,000 Km usage but twice after 15,000 Km usage. These experiments reflected that some additional technical measures should be taken to offset these technical challenges before biodiesel is adapted on a large-scale in modern CRDI vehicles.