Abstract: A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a sensor configured to generate a signal indicative of an amount of an air/fuel mixture remaining within the cylinder after completion of a first combustion event and a controller in communication with the actuator and the sensor. The controller may be configured to compare the amount with a desired amount, and to selectively regulate the actuator to adjust a timing of the engine valve associated with a subsequent combustion event based on the comparison.

Abstract: An air induction system for an engine is disclosed. The air induction system has a compressor operable to compress air directed into the engine, a bypass valve, and a throttle valve. The bypass valve may be disposed between the compressor and the engine and may have a valve element movable to selectively divert a portion of the compressed air away from the engine in response to a desired air-to-fuel ratio of the engine. The throttle valve may be disposed between the bypass valve and the engine and may have a valve element movable to selectively restrict the flow of compressed air into the engine in response to a desired air-to-fuel ratio of the engine. The movements of the valve elements of the bypass and throttle valves may be substantially sequential.

Abstract: An engine assembly may include an internal combustion engine configured to combust a gaseous fuel. The engine assembly may also include a fuel intake line operatively connected to the internal combustion engine. The fuel intake line may be configured to direct the gaseous fuel towards the internal combustion engine. The engine assembly may further include a refrigeration assembly operatively connected to the fuel intake line. The refrigeration assembly may be configured to cool the gaseous fuel in the fuel intake line.

Abstract: An internal combustion engine has at least one combustion chamber and a piston configured to reciprocate within the at least one combustion chamber between a top-dead-center position and a bottom-dead-center position. The internal combustion engine also has a pre-combustion chamber, an air induction system, a fuel system, a spark plug at least partially disposed within the pre-combustion chamber. The air induction system is configured to direct air into the at least one combustion chamber. The fuel system is configured to direct gasoline into the at least one combustion chamber. The spark plug is configured to selectively ignite a mixture of the air and gasoline. The internal combustion engine also has an exhaust system configured to direct exhaust from the at least one combustion chamber and an exhaust gas recirculation system configured to selectively redirect at least a portion of the exhaust from the exhaust system back to the air induction system.

Abstract: A method and apparatus for operating an internal combustion engine is provided. The method comprises the steps of introducing a primary fuel into a main combustion chamber of the engine, introducing a pilot fuel into the main combustion chamber of the engine, determining an operating load of the engine, determining a desired spark plug ignition timing based on the engine operating load, and igniting the primary fuel and pilot fuel with a spark plug at the desired spark plug ignition timing. The method is characterized in that the octane number of the pilot fuel is lower than the octane number of the primary fuel.

Abstract: A method and apparatus for providing a hydrogen enriched fuel to a combustion prechamber. The method and apparatus includes reforming a quantity of fuel to produce a hydrogen enriched fuel, delivering the reformed fuel to the combustion prechamber, and combining the hydrogen enriched fuel with a fuel/air mixture to less than stoichiometric.

Abstract: A method and apparatus for injecting pilot fuel in a combustion engine. The method and apparatus includes determining a load of the engine, determining a desired injection timing of the pilot fuel and a desired quantity of pilot fuel to be injected as a function of a desired homogeneous distribution of the pilot fuel based on the engine load, and adjusting the injection timing and quantity of the pilot fuel to the desired values.

Abstract: A method and apparatus for injecting pilot fuel in a combustion engine. The method and apparatus includes determining a load of the engine, determining a desired injection timing of the pilot fuel and a desired quantity of pilot fuel to be injected as a function of a desired homogeneous distribution of the pilot fuel based on the engine load, and adjusting the injection timing and quantity of the pilot fuel to the desired values.

Abstract: A method and apparatus for providing a hydrogen enriched fuel to a combustion prechamber. The method and apparatus includes reforming a quantity of fuel to produce a hydrogen enriched fuel, delivering the reformed fuel to the combustion prechamber, and combining the hydrogen enriched fuel with a fuel/air mixture to less than stoichiometric.

Abstract: Reduction of nitrogen oxide emissions during operation of an engine is achieved by using a fuel mixture therein which includes a gaseous fuel and an emulsified pilot fuel. The method includes the steps of (i) advancing air into a combustion chamber of the engine, (ii) advancing a gaseous fuel into the combustion chamber, (iii) injecting an emulsified pilot fuel into the combustion chamber, wherein the emulsified pilot fuel includes water and liquid fuel, and (iv) compressing a mixture which includes (A) the air, (B) the gaseous fuel, and (C) the emulsified pilot fuel within the combustion chamber during a compression stroke of the engine, whereby heat generated by compression of the mixture causes the emulsified pilot fuel to combust so as to ignite the gaseous fuel.

Abstract: A method for controlling and adjusting the delivery of liquid pilot fuel to each cylinder of a dual fuel engine during a dual fuel operating mode so as to both minimize the quantity of liquid pilot fuel being delivered to each individual cylinder while, at the same time, ensuring that such minimum quantity of liquid pilot fuel provides complete combustion performance within each such cylinder wherein certain cylinder performance parameters such as exhaust port temperature or cylinder pressure are evaluated on a per cylinder basis in order to determine cylinder performance. The present method establishes certain predetermined incremental changes in the selected cylinder performance parameters, which changes are indicative of poor or deteriorated combustion performance within any particular cylinder, and thereafter varies the amount of liquid pilot fuel delivered to such cylinder based upon an analysis and evaluation of changes occurring in the selected cylinder performance parameters.

Abstract: A method for controlling delivery of fuel to each cylinder of an engine by adjusting the appropriate fuel valve duration times to each such cylinder based upon a predetermined detonation level. By using the detonation level measurements from each individual cylinder as a controlling parameter, the delivery of fuel to that particular cylinder can be trimmed to achieve the predetermined detonation level. Balancing the detonation level for each such cylinder to a common detonation level likewise produces a substantially identical air/fuel ratio in each such cylinder. The detonation control loop can be initiated at predetermined intervals so as to continuously maintain a balanced air/fuel ratio to each cylinder in any particular engine.

Abstract: A method for transitioning between a first operating mode of a dual fuel engine and a second operating mode of the dual fuel engine includes establishing a final liquid fuel amount desired to be delivered to the engine upon completion of the transition to the second operating mode. Delivery of liquid fuel to the engine is adjusted by a first amount and, correspondingly, delivery of gaseous fuel to the engine is adjusted by a second amount, where an energy content of the first amount of liquid fuel is substantially the same as an energy content of the second amount of gaseous fuel. A determination is made as to whether liquid fuel is being delivered to the engine in an amount which is substantially the same as the desired final liquid amount previously established.

Abstract: A method of operating an engine assembly having a cylinder assembly which defines a combustion chamber is disclosed. The cylinder assembly includes an engine block having a piston cylinder defined therein, a piston which translates in the piston cylinder, and a crankshaft which is mechanically coupled to the piston. The method includes the steps of performing an intake stroke of the engine assembly and advancing gaseous fuel and air into the combustion chamber during the intake stroke performing step. The method further includes the step of performing a compression stroke of the engine assembly after the is intake stroke performing step. The method yet further includes the step of injecting a pilot fuel into the combustion chamber during the compression stroke while the crankshaft is positioned at about X degrees before top dead center, wherein 21.0<X<28.0.

Abstract: A method for adjusting a fuel control system of an internal combustion engine to account for variations in the energy content of a fuel delivered to the engine involves monitoring the O.sub.2 level of the engine exhaust gases. The fuel may be a gaseous fuel for example. The fuel control system utilizes a stored gaseous fuel energy content value (E.sub.G) to determine the necessary duration of a gaseous fuel admission valve control signal. The method includes sensing an actual engine exhaust gas O.sub.2 level and comparing the actual exhaust gas O.sub.2 level with a desired exhaust gas O.sub.2 level. The stored gaseous fuel energy content value (E.sub.G) is adjusted based upon the comparison. The desired exhaust gas O.sub.2 level may be determined as a function of one or more engine operating parameters which indicate a desired or expected air/fuel ratio, the level of O.sub.2 in the exhaust gases being an indicator of the air/fuel ratio.

Abstract: A method of detecting leakage through a gaseous fuel admission valve of a dual fuel engine including at least one such gaseous fuel admission valve and a gaseous fuel shut off valve includes determining a liquid fuel rate when the engine is operating in a liquid fuel mode and the gaseous fuel shut off valve is closed. The gaseous fuel shut off valve is thereafter opened while the engine is operating in the liquid fuel mode. A liquid fuel rate is determined after the gaseous fuel shut off valve is opened and the liquid fuel rate determined before opening of the gaseous fuel shut off valve is compared with the liquid fuel rate determined after opening of the gaseous fuel shut off valve. A detonation level within the engine cylinder may also be checked to determine if such detonation level exceeds a predetermined level indicative of gaseous fuel leakage. The detonation level check may also be utilized in a spark-ignited engine.

Abstract: A method of operating an engine assembly having a cylinder assembly which defines a combustion chamber is disclosed. The method includes the steps of performing an intake stroke of the cylinder assembly and advancing a conditioning fuel into the combustion chamber during the intake stroke performing step. The method further includes the steps of advancing a gaseous fuel into the combustion chamber during the intake stroke performing step and performing a compression stroke of the cylinder assembly after the intake stroke performing step. The method yet further includes the steps of advancing a pilot fuel into the combustion chamber during the compression stroke performing step and combusting the pilot fuel in the combustion chamber during the compression stroke performing step so as to ignite the conditioning fuel and the gaseous fuel.

Abstract: A method for responding to detection of an open fault condition in a gaseous fuel admission valve for providing a flow of gaseous fuel to an affected combustion cylinder of an engine, the engine including at least one other gaseous fuel admission valve for providing a flow of gaseous fuel to at least one other combustion cylinder, a gaseous fuel shut off valve for controlling gaseous fuel flow from a source of gaseous fuel to a gaseous fuel manifold in communication with the gaseous fuel admission valve, and apparatus for causing ignition of a mixture of the gaseous fuel and air in each combustion cylinder.

Abstract: A method for controlling delivery of fuel to each cylinder of an engine by adjusting the appropriate fuel valve duration times to each such cylinder based upon either a desired cylinder exhaust port temperature, or a predetermined detonation level. By using the exhaust port temperature measurements and/or detonation level measurements from each individual cylinder as a controlling parameter, the delivery of fuel to that particular cylinder can be trimmed to achieve the desired exhaust port temperature and/or predetermined detonation level. Balancing the exhaust port temperature and/or detonation level for each such cylinder to a common desired exhaust port temperature and/or detonation level likewise produces a substantially identical air/fuel ratio in each such cylinder.

Abstract: A method for adjusting a fuel control system of an engine capable of operating in both a first mode during which only a first fuel is delivered to the engine and a second mode during which both the first fuel and a second fuel are delivered to the engine includes operating the engine in the first mode during which a governor output value (X.sub.M1) is established and stored in memory. The engine is then operated in the second mode during which a governor output value (X.sub.M2) is established. The governor output value (X.sub.M2) is compared with the stored governor output value (X.sub.M1) and a stored second fuel energy content value is adjusted based upon the comparison. The actual energy content of the second fuel can also be directly calculated.