Surging is reliably prevented from occurring even when an engine with a
turbocharger is operated with reduced number of cylinders and at a low
speed range.Concerned is a method for controlling actuation of valves in
an engine with a turbocharger, a variable valve mechanism 18 being
arranged for controlling opening/closing timing and lifts of suction and
exhaust valves (only exhaust valves 17 being shown in the figure) of each
of cylinders 8, an operation with reduced number of cylinders being made
possible by the variable valve mechanism 18 such that valve-opening
action of suction and exhaust valves in part of the cylinders 8 is
disabled to conduct the operation with the remaining cylinders 8. The
exhaust valves 17 are opened substantially when a suction pressure is
higher than an exhaust pressure in a suction stroke during the operation
with the reduced number of cylinders at a low speed range, so that blown
out amount of fresh air (suction air 4) to the exhaust side is increased
to increase apparent exhaust flow rate and raise the level of the suction
characteristic of the engine.