Investigative study of engine limiting

Abstract

An experimental study was conducted to determine the effect of cylinder cutout or "engine limiting" on fuel consumption and exhaust emissions for a current technology V-type 8-cylinder engine. Increases in energy conversion efficiency while operating with only 4 cylinders ranged from 10 to 40 pct compared to operation with 8 cylinders at the same power outputs. The speeds and loads chosen were representative of those required to operate a 4,500-lb vehicle at speeds up to 60 mph. Hydrocarbon emissions increased at low speed/ load points under 4 cylinder operation. An insignificant change in carbon monoxide emissions was observed while an increase in oxides of nitrogen emissions resulted at the higher speed/load points.