High-Pressure Late Cycle Direct Injection of Natural Gas in a Rail Medium Speed Diesel Engine

The performance of an Electro-Motive Division (EMD) 567B, two-cylinder locomotive research engine, when operated on high-pressure/late-cycle injection of natural gas, is presented in this paper. A redesign and fabrication of the fuel system was undertaken to facilitate the consumption of natural gas. A small percentage of No. 2 diesel fuel (DF-2) was used to ignite the natural gas. Engine performance, while running natural gas, resulted in matching rated speed and power with slightly tower thermal efficiency. Full power was achieved with a ratio of 99 percent natural gas and 1 percent diesel fuel. However, at high natural gas to diesel fuel ratios, audible knock was detected.