| Scope and Method of Study. The cost escalations, quality deterioration and supply disruptions of the traditional sources of diesel engine fuel have recently generated a great interest among the agricultural scientists to find an alternative source of energy for diesel engines. Vegetable oil has been found by researchers, as a very promising source due to its diesel-like fuel properties, renewability and on-farm availability.; The performance, reliability and durability of two single cylinder diesel engines burning vegetable oil, and its blends with diesel fuel, were evaluated and compared to that of the engines burning neat diesel fuel. The short term performance i.e. maximum power output, specific fuel consumption, brake thermal efficiency and exhaust smoke of each engine run on each fuel were determined with the help of an electric dynamometer. The long term performance in terms of reliability, durability of the engine were evaluated in a series of 200-hour endurance tests, burning the fuels which were selected on their viability as alternative fuel during the short term test. The injector nozzle performance, exhaust smoke density, lubricating oil consumption and its quality deterioration, wear of engine internal parts and carbon deposit around combustion chamber components of the engines burning alternative fuels were evaluated and compared to those found using diesel as a reference fuel.; Findings and Conclusions. The engine equipped with a dual-fuel system, and adjusted to run on #2 diesel, produced 1-5% less maximum power, consumed 1-14% more fuel by mass, developed 1-10% less brake thermal efficiency, while burning alternative fuels, compared to those obtained with #2 diesel. Injector performance, oil consumption, oil dilution, engine wear, carbon deposit, exhaust smoke density, all remained within acceptable limits. The indirect injection engine performed better in respect of power output, fuel consumption, thermal efficiency and durability than did the direct injection engine. The laboratory tests confirmed that 10-25% (by volume) of test vegetable oils with the rest of fuel blend being #2 diesel, would perform satisfactorily as an emergency diesel engine fuel. |
