Abstract: A conversion system for converting a spark ignition engine to operate on gaseous fuel is disclosed. The conversion system includes an electronic controller which operates on several novel principles to provide superior performance/responsiveness and to reduce exhaust emissions. The controller in accordance with the invention assumes complete control of spark ignition timing when gaseous fuel mode is enabled and generates independent spark ignition signals tailored to the gaseous fuel. The controller also generates an independent pulse width modulated gaseous fuel injection signal that controls a high performance electronic solenoid injector valve to supply gaseous fuel to the engine. Variable injector speed is used to compensate for the dynamic range of the engine. A novel dual array block learn scheme is used to provide efficient fuel control in engines equipped with closed-loop monitoring systems and exhaust gas recirculation.

Abstract: A compact reversing flow catalytic converter for reducing noxious substances in exhaust gases produced by internal combustion engines is described. The catalytic converter includes a valve unit which reversibly directs exhaust gases through a container filled with catalytic material. The container defines a U-shaped gas passage which communicates with two ports at a top of the container. The valve unit is mounted to the top of the container and includes an intake and an exhaust cavity. The valve unit includes a valve disk having two openings therethrough and rotates around a perpendicular central axis between a first and second position. In each position, each opening communicates only with one of the cavities and one of the ports. In the first position, the exhaust gases enter the exhaust cavity from an exhaust pipe and pass through one of the openings into the gas passage where they contact the catalytic material as they travel through the U-shaped gas passage and enter the exhaust cavity.

Abstract: A conversion system for converting a spark ignition engine to operate on gaseous fuel is disclosed. The conversion system includes an electronic controller which operates on several novel principles to provide superior performance/responsiveness and to reduce exhaust emissions. The controller in accordance with the invention assumes complete control of spark ignition timing when gaseous fuel mode is enabled and generates independent spark ignition signals tailored to the gaseous fuel. The controller also generates an independent pulse width modulated gaseous fuel injection signal that controls a high performance electronic solenoid injector valve to supply gaseous fuel to the engine. Variable injector speed is used to compensate for the dynamic range of the engine. A novel dual array block learn scheme is used to provide efficient fuel control in engines equipped with closed-loop monitoring systems and exhaust gas recirculation.

Abstract: An exhaust gas recirculation system for a compression ignition engine and a method of controlling exhaust gas recirculation in compression ignition engines are disclosed. The method and apparatus are adapted to the control of exhaust gas recirculation in diesel and/or multifuel (e.g. diesel and natural gas) engines.