Abstract: A two-stroke, opposed-piston engine with one or more ported cylinders and uniflow scavenging includes an exhaust gas recirculation (EGR) construction that provides a portion of the exhaust gasses produced by the engine for mixture with charge air to control the production of NOx during combustion.

Abstract: A combustion chamber for an opposed-piston engine includes a squish zone defined between circumferential peripheral areas of opposing end surfaces of the pistons, a cavity defined by one or more bowls in the end surfaces, and at least one injection port that extends radially through the squish zone into the cavity. The cavity has a cross-sectional shape that imposes a tumbling motion on air flowing from the squish zone into the cavity.

Abstract: A control system and method for improving vehicle fuel economy is provided. A base timing module generates a base timing signal. A trim module generates a timing trim signal based on a calibratable compensation factor. A vehicle speed trim module adjusts a calibration parameter (such as engine timing for example) based on the base timing signal and the timing trim signal. According to some implementations, the trim module includes a base trim module and a vehicle speed compensation module and a calibratable compensation factor module. The vehicle speed compensation module generates a vehicle speed compensation factor. The base trim module generates a base trim signal based on the vehicle speed compensation factor or the calibratable compensation factor. The base trim signal can be based on a speed of the engine. The base trim signal can further be based on a quantity of fuel delivered to the engine.

Abstract: An exhaust after-treatment system for a vehicle including a dosing agent that is selectively injected into an exhaust from a dosing agent supply includes a first module that determines a level of a dosing agent source. A second module selectively impedes vehicle operation by adjusting an engine operating mode if the level of said dosing agent source is below a threshold level.

Abstract: A control system and method for improving vehicle fuel economy is provided. A base timing module generates a base timing signal. A trim module generates a timing trim signal based on a calibratable compensation factor. A vehicle speed trim module adjusts a calibration parameter (such as engine timing for example) based on the base timing signal and the timing trim signal. According to some implementations, the trim module includes a base trim module and a vehicle speed compensation module and a calibratable compensation factor module. The vehicle speed compensation module generates a vehicle speed compensation factor. The base trim module generates a base trim signal based on the vehicle speed compensation factor or the calibratable compensation factor. The base trim signal can be based on a speed of the engine. The base trim signal can further be based on a quantity of fuel delivered to the engine.

Abstract: A control system and method for improving vehicle fuel economy is provided. A base timing module generates a base timing signal. A trim module calculates a vehicle speed compensation factor and generates a timing trim signal based on the vehicle speed compensation factor. A vehicle speed trim module adjusts a calibration parameter (such as engine timing for example) based on the base timing signal and the timing trim signal. According to some implementations, the trim module includes a base trim module and a vehicle speed compensation module. The base trim module generates a base trim signal. The vehicle speed compensation module generates the vehicle speed compensation factor. The base trim signal can be based on a speed of the engine. The base trim signal can further be based on a quantity of fuel delivered to the engine.

Abstract: An EGR system compensates for differing EGR flows and/or exhaust temperatures and can maintain the cooler exit temperature above the critical temperature, thereby reducing the possibility of EGR cooler fouling. A plurality of exhaust gas recirculation cooler modules is disposed between an exhaust gas passage and an air passage. The cooler modules receive exhaust gas from the exhaust gas passage and supply the received exhaust gas to the air passage for recirculation into an intake manifold. Each of the cooler modules includes a cooler portion, a bypass portion, and a flow control device. The cooler portion and the bypass portion are arranged such that fluid flowing through the cooler portion and the bypass portion flows therethrough without flowing through the other of the cooler portion and the bypass portion. The cooler portion reduces a temperature of the fluid flowing through the cooler portion.

Abstract: A multiple path air mass flow sensor assembly includes an inlet duct which is divided into at least two separate ducts. A first duct has an air mass flow sensor disposed in conventional fashion therein. A second duct includes a damper or valve which may be selectively, partially or fully opened. At low air flow rates, the damper is closed forcing all air through the first duct. As engine speed increases and the air mass flow rate increases, the damper opens, either fully at a predetermined flow rate or proportionally over a predetermined flow rate range, to allow a larger volume of air through the inlet duct. The signal from the air mass flow sensor is adjusted by the engine controller to compensate for the (bypass) air flowing through the second duct.

Abstract: A control system and method for improving vehicle fuel economy is provided. A base timing module generates a base timing signal. A trim module calculates a vehicle speed compensation factor and generates a timing trim signal based on the vehicle speed compensation factor. A vehicle speed trim module adjusts a calibration parameter (such as engine timing for example) based on the base timing signal and the timing trim signal. According to some implementations, the trim module includes a base trim module and a vehicle speed compensation module. The base trim module generates a base trim signal. The vehicle speed compensation module generates the vehicle speed compensation factor. The base trim signal can be based on a speed of the engine. The base trim signal can further be based on a quantity of fuel delivered to the engine.

Abstract: A method for calibrating an engine is provided. The engine includes a cylinder for combustion of a fuel. The method includes setting combustion parameters of the engine, detecting a combustion noise during combustion proximate to the cylinder, detecting an engine sound radiated from the engine during combustion, adjusting the combustion parameters and repeating the steps of detecting a combustion noise and detecting an engine sound. The method further includes generating a relationship between the combustion noises and the engine sounds, determining a combustion noise level that correlates to a predefined engine sound threshold from the relationship, adjusting a speed of the engine and a load on the engine and repeating the previous steps to determine a combustion noise level for each engine speed and engine load setting, and calibrating the engine using the combustion noise levels.

Abstract: A multiple path air mass flow sensor assembly includes an inlet duct which is divided into at least two separate ducts. A first duct has an air mass flow sensor disposed in conventional fashion therein. A second duct includes a damper or valve which may be selectively, partially or fully opened. At low air flow rates, the damper is closed forcing all air through the first duct. As engine speed increases and the air mass flow rate increases, the damper opens, either fully at a predetermined flow rate or proportionally over a predetermined flow rate range, to allow a larger volume of air through the inlet duct. The signal from the air mass flow sensor is adjusted by the engine controller to compensate for the (bypass) air flowing through the second duct.

Abstract: A method for calibrating an engine is provided. The engine includes a cylinder for combustion of a fuel. The method includes setting combustion parameters of the engine, detecting a combustion noise during combustion proximate to the cylinder, detecting an engine sound radiated from the engine during combustion, adjusting the combustion parameters and repeating the steps of detecting a combustion noise and detecting an engine sound. The method further includes generating a relationship between the combustion noises and the engine sounds, determining a combustion noise level that correlates to a predefined engine sound threshold from the relationship, adjusting a speed of the engine and a load on the engine and repeating the previous steps to determine a combustion noise level for each engine speed and engine load setting, and calibrating the engine using the combustion noise levels.

Abstract: An exhaust after-treatment system for a vehicle including a dosing agent that is selectively injected into an exhaust from a dosing agent supply includes a first module that determines a level of a dosing agent source. A second module selectively impedes vehicle operation by adjusting an engine operating mode if the level of said dosing agent source is below a threshold level.

Abstract: An exhaust gas recirculation (EGR) system and method for simple and rapid introduction of EGR gas to an internal combustion engine include a pump, tank, and valve connected to the engine. Exhaust gas is pressurized by operation of the pump under predetermined operating conditions and stored in the tank. The valve is selectively controlled to meter amounts of the EGR gas to the engine. The EGR tank can be separate or integrally formed within tubing used to direct EGR gas flow.