Abstract: A two-stroke engine comprising at least one cylinder having a combustion chamber, an exhaust duct connected to the combustion chamber, at least one duct for the intake of fresh gas compressed by a compression device for delivering said fresh compressed gas, at least a first rotary valve opens and closes the exhaust duct and at least a second rotary valve feeds fluid into the combustion chamber.

Abstract: The method comprises detecting, during the combustion phase in at least one engine cylinder, the angular position of the crankshaft at which the value of the ratio of the volume of burnt gases to the overall gas volume in the cylinder reaches a preselected value, and adjusting the ignition timing to make said detected position of the crankshaft coincide with a predetermined position. The method also includes detecting for all cycles of operation the flame front in all the cylinders of the engine. The number of signals delivered by one of the detectors are counted for a specified number of cycles of operation of the engine and the average value of the change in angular position of the crankshaft during which time said signals are counted is determined. Accordingly, depending upon whether the number of signals counted in another cylinder falls below or above the count in the first cylinder, a corresponding reference signal is produced for controlling ignition timing.

Abstract: A process and device is provided for automatically regulating the running conditions of an internal combustion engine. The engine is of the type fed with different fuels, and in accordance with the nature and the composition of the fuel or fuel mixture contained in the feed tank of the engine, at any moment, including that of a new fuel supply at a filling station, the regulator is monitored by a data processing unit delivering signals representative of the amount and the characteristics of the fuel contained in the tank before and after a new fuel supply.

Abstract: A method is provided for the automatic control of the ignition time in a spark ignition engine or the injection time in a compression-ignition engine wherein at least one typical phenomenon of the running conditions of the engine, such as the occurrence of the peak pressure in the cylinder within a certain angular interval of the crankshaft, or the passage of the flame front through a reference position of the combustion chamber is detected, and the detected measurements have an aleatory character. This method comprises the determination of a statistical value representative of at least P validated measurements, of said phenomenon occurring during at most Q cycles, and the use of said statistical value to modify the control time of the combustion initiation so that said statistical value takes a predetermined value corresponding to the desired running conditions.

Abstract: An accelerometer located on the cylinder head of an engine supplies a signal which is twice integrated thus giving a resulting signal whose peak value is detected. The spark advance is automatically adjusted so that this peak value occurs in a preselected angular position of the crankshaft. The advance may also be similarly adjusted based instead on the null point of the signal which results after an integration of the signal coming from the accelerometer.

Abstract: An accelerometer located on the cylinder head of the engine supplies a signal which is twice integrated thus giving a resulting signal whose peak value is detected. The spark advance is automatically adjusted so that this peak value occurs in a preselected angular position of the crankshaft.

Abstract: This device comprises, in combination, means generating a digital value equal to the difference between a number of cycles of the engine and the number of knockings detected during the period of said cycles and means controlling the spark advance point in response to said difference.