A method for detecting the quantity of gas (m) supplied by a gas supply device to an antechamber of an internal combustion engine. The method includes causing a targeted disturbance (u) of the gas quantity (m) supplied by the gas supply device, and measuring a change (T) resulting from the target disturbance (u) in an exhaust gas temperature (T) of an exhaust gas generated in a combustion chamber connected to the antechamber. The method includes comparing the change (T) with a target value of the change (Ttarget) of the exhaust gas temperature (T) to obtain a comparison, and deducing the gas quantity (m) supplied by the gas supply based on the comparison.

A method for detecting the quantity of gas (m) supplied by a gas supply device to an antechamber of an internal combustion engine. The method includes causing a targeted disturbance (u) of the gas quantity (m) supplied by the gas supply device, and measuring a change (T) resulting from the target disturbance (u) in an exhaust gas temperature (T) of an exhaust gas generated in a combustion chamber connected to the antechamber. The method includes comparing the change (T) with a target value of the change (Ttarget) of the exhaust gas temperature (T) to obtain a comparison, and deducing the gas quantity (m) supplied by the gas supply based on the comparison.

An engine is equipped with a gas feeding system, including main gas injectors each associated with an intake duct of a respective engine cylinder, a gas distribution manifold communicating with said main injectors, a gas tank, connected to the manifold, where pressurized gas is accumulated, a controlled pressure valve interposed between the tank and manifold, and a control unit for controlling the pressure valve to establish a gas pressure in the manifold. A spark plug of each cylinder is mounted within a support body that defines a combustion pre-chamber and a channel for auxiliary gas injection within the pre-chamber, communicating with a respective auxiliary gas injector. The auxiliary gas injectors are in communication with the manifold, downstream of the pressure valve. In the channel, a non-return valve and a restricted passage are provided in series, providing for passage of gas flow proportional to a volume of the pre-chamber.

An engine has, for each cylinder, a combustion chamber and a combustion pre-chamber communicating with the combustion chamber. First and second spark plugs are associated with the pre-chamber and combustion chamber, respectively. Gasoline is injected by an injector device directly into the combustion chamber and/or by an injector device into a cylinder intake duct. There is no device for injecting gasoline, air or an air/gasoline mixture directly into the pre-chamber. The engine operates with an air/gasoline mixture substantially corresponding to stoichiometric, for compatibility with an exhaust system having a trivalent catalyst. The pre-chamber is not used for engine operation with poor dosing, but to increase resistance to engine detonation. The engine can thus be configured with a high compression ratio, with a significant reduction in fuel consumption at the same power level. The second spark plug is only activated at low and medium engine loads to stabilize combustion.

A method for combustion in a combustion chamber of an internal combustion engine includes mixing fuel and air to form a charge, flowing a first portion of the charge to the main chamber of an engine and a second portion of the charge to the pre-chamber volume of an engine, igniting the second portion of the charge in the pre-chamber volume, and delivering the ignited second portion of the charge to the main chamber.

A method for combustion in a combustion chamber of an internal combustion engine includes mixing fuel and air to form a charge, flowing a first portion of the charge to the main chamber of an engine and a second portion of the charge to the pre-chamber volume of an engine, igniting the second portion of the charge in the pre-chamber volume, and delivering the ignited second portion of the charge to the main chamber.

In certain embodiments, a time-varying spark current ignition system can be applied to improve spark plug ignitability performance and durability as compared to conventional spark ignition systems. Two performance parameters of interest are spark plug life (durability) and spark plug ignitability. In certain embodiments, spark plug life can be extended by applying a spark current amplitude as low as possible without causing quenching of the flame kernel while it is traveling within an electrode gap and/or by applying spark current of a long enough duration to allow the spark/flame kernel to clear a spark plug gap. In certain embodiments, ignitability can be improved by applying a high enough spark current amplitude to sustain the flame kernel once outside the spark plug gap and/or by applying a spark current for long enough to sustain the flame kernel once outside the spark plug gap.

A rotary engine having an outer body having an internal cavity with a peripheral wall having an insert opening defined therethrough in communication with the internal cavity, and a plurality of coolant passages defined through the peripheral wall in proximity of the insert opening, a rotor body rotatable within the internal cavity, and an insert removably received in the insert opening of the peripheral wall, the insert having a subchamber defined therein communicating with the internal cavity, with a minimum width of the insert opening being at least 0.75 inches. An outer body for a rotary engine and a method of inspecting in an internal cavity in an outer body of a rotary engine are also discussed; also, a rotary engine including a fuel injector having a tip received in the injector hole of the peripheral wall without protruding in the insert opening.

Apparatuses, methods, and systems for starting an internal combustion engine under cold start conditions are disclosed. A combustible mixture is supplied to a plurality of cylinders of the internal combustion engine, where a number of ignition devices are operably connected with less than all of the plurality of cylinders so that at least one of the plurality of cylinders does not include an ignition device. In one form, only one ignition device is included in a bank of cylinders. In response to a cold start condition, a spark by the plurality of ignition devices is generated to cause ignition of the combustible mixture and start the internal combustion engine. In response to a normal or non-cold starting condition, the internal combustion engine is started by compression ignition where none of the ignition devices generate a spark.

A method for operating an internal combustion engine including feeding a pilot quantity of gas fuel, into a prechamber before a piston reaches a top dead center position. The method comprises autoignition of the pilot quantity of gas fuel in the prechamber, feeding a main quantity of gas fuel into the prechamber after the autoignition, and ignition of the main quantity of gas fuel by the conditions in the prechamber that are brought about by the autoignited pilot quantity. The method makes it possible to operate an internal combustion engine purely with methane or some other gaseous fuel, by means of compression autoignition of the pilot quantity.