The present invention relates to a two-cycle diesel engine comprising an exhaust passage (18) with an exhaust control valve (192) for controlling the aperture of said exhaust passage and a scavenge passage arrangement (56) with a scavenging control valve (16c) for controlling the rate of scavenging. The engine is improved in that a detection means (50-55) is provided for detecting an engine operating condition and a control device (44) is provided for controlling the aperture of said exhaust control valve and said scavenging control valve respectively in response to the engine operating condition. <IMAGE>
