Two-stage injection reduces diesel cetane requirements

The goal was to determine the feasibility of expanding the cetane-number tolerance of a laboratory Electro-Motive Div. (EMD) 567B medium-speed diesel engine via staged injection and finding to what degree it could be used. Explains that dividing the total charge of a low-cetane-number fuel between a pilot and main injection can provide satisfactory medium speed diesel operation at essentially no thermal efficiency cost. A second injection system was added to the EMD engine, and various cetane ratings were obtained by blending No. 2 diesel fuel with a naphtha. Finds that methanol staged injection might not be warranted considering the lower compression ratios which could be used with pilot diesel fuel ignition and cold starting problems which might result with methanol staged injection.