Abstract
“Cylinder cut” is a well known energy saving technology in the automotive field. This method involves stopping several cylinders of an engine during slow speed operation to decrease “pumping loss”, which refers to the air suction resistance at the throttle valve. The authors applied this technology to a marine engine although it has no throttle valve, considering that combustion conditions may improve with higher load for each cylinder. One cylinder cut and two cylinder cut were tested on a 7 cylinder engine (7S65ME-C) at MES Tamano factory. Date as well as related observations are presented.