DURABILITY TESTING OF A DIESEL FUEL, METHYL TALLOWATE, AND ETHANOL BLEND IN A CUMMINS N-14-410 DIESEL-ENGINE

A Cummins N14-410 diesel engine was operated on an 80:13:7% (v/v) blen d of diesel fuel:methyl tallowate:ethanol. The standard 200-h Engine M anufacturers Association (EMA) test procedure was followed to rest eng ine durability. Engine performance was evaluated in terms of power pro duced at rated speed, peak torque produced at a speed of 1 200 rpm, an d brake specific fuel consumption at both speeds. Engine exhaust emiss ions analyses were performed, and the engine oil was analyzed for accu mulation of heavy metals at 45 h intervals. It was observed that engin e performance was satisfactory for 148 h at which time the injector in cylinder 2 failed The injector was changed, and after an additional 1 1 h (159 h total) of operation the injector in cylinder 5 failed. That injector also was replaced, and the 200-h procedure was continued. Th e test was discontinued after 197 h when the supply of the fuel blend was exhausted. The injectors were removed and the injector in cylinder 1 was observed to be coked. This injector was sent to the Cummins Eng ine Co. for analysis. If was found that failure of this injector was n ot because of the fuel used, but because a crack had developed across the tip due to an excessively tight overhead adjustment. This induced excessive force in the crush load, thus exceeding the strength of the nozzle. The power output, torque produced, and brake specific fuel con sumption of the engine was more or less constant throughout the test. Emissions analyses at 45-h intervals did not show any increase in exha ust gases or deterioration of engine performance. Engine oil analyses performed for accumulation of wear metals did not reveal any excessive wear on the engine parts.