Method of controlling the ignition in an internal combustion engine and engine with means for carrying out the method

Method in an internal combustion engine with at least one cylinder, a crankshaft and at least one inlet valve and at least one exhaust valve for each cylinder, of adapting the ignition timing relative to the crankshaft position to variations in engine operating conditions, characterized in that the ignition timing is varied in relation to variations in the period of time when the inlet and exhaust valves are open at the same time, by computing the ratio between combusted and non-combusted gas in the combustion chambers of the cylinders and utilizing this ratio in such a manner that the larger the proportion of combusted gas is, the earlier the ignition will be initiated.