Abstract: The invention provides a supercharged engine including a supercharger and an intercooler disposed downstream of the supercharger. The engine has a geometric compression ratio equal to or higher than 8.5. The supercharger is an internal compression type mechanical supercharger having a pressure ratio higher than 1.8 wherein the pressure ratio is defined as a ratio of a pressure at an inlet opening to a pressure at an exit opening of the supercharger. Intake valve closing timing of the engine supercharger is in the range of 50 to 100 degrees in crank angle as measured from bottom dead center, and an overlapping period during which both intake and exhaust valves open is equal to or below 17 degrees in crank angle wherein the intake valve closing timing is defined as the timing when valve lift is equal to or less than 1 millimeter, and the overlapping period is to be measured on the basis of a valve lift of zero.

Abstract: An intake system for a multiple-cylinder engine a plurality of primary discrete intake passages and a plurality of secondary discrete intake passages. Each pair of primary discrete intake passage and the secondary discrete intake passage communicate with one of the cylinders. Both the primary and secondary discrete intake passages are straight and the primary discrete intake passage is provided with a primary valve member which is provided with an opening and is selectively positioned in a closed position where the primary valve member limits the effective cross-sectional area of the primary discrete intake passage to the cross-sectional area of the opening and in an open position where the primary valve member wide opens the primary intake passage.

Abstract: A fuel supply arrangement for an internal combustion engine, including an adjusting device for adjusting supply amount of fuel to the engine, an air temperature sensor for detecting temperature of intake air, a correcting device for correctively controlling the adjusting device on the basis of an output of the air temperature sensor, a detecting device for detecting a specific engine operating condition where the output of the air temperature sensor is higher than an actual temperature of the intake air, and a restricting device for restricting corrective control of the correcting device in response to a detection output of the detecting device.