Method of controlling the process of combustion in an internal combustion engine, and engine with means for varying the effective compression ratio of the cylinders

Method of controlling the combustion process in the combustion chamber of a four-stroke internal combustion engine with at least one cylinder having at least one inlet valve and one exhaust valve, means for varying the geometric compression ratio of the cylinder, and means for supplying a homogeneous fuel/air mixture to the combustion chamber,

• wherein the compression ratio and the closing of the inlet valve are controlled so that the mixture, at least within a lower rpm range, is compressed to self-ignition, and
• wherein the combustion ratio and the closing of the inlet valve are controlled so that the compression ratio will be higher and the valve close earlier at low loads and high engine speed than at high loads and low engine speed, that the compression ratio is reduced and the closing of the valve is set later intransient states to high load and low engine speed, and that the compression ratio is raised and the valve is closed earlier in transient states to low load and high engine speed.