A power system includes an intake arrangement and a compression ignition engine including piston-cylinder sets. Each piston-cylinder set includes: a cylinder; a piston positioned within the cylinder to form a combustion chamber in between; an intake valve configured to open and close the intake port; an exhaust valve configured to open and close the exhaust port; and a fuel injector. During an exhaust stroke, the exhaust valve is opened to enable exhaust gas to flow out; during an initial portion of an intake stroke, the intake valve is opened to enable the intake air to flow into the combustion chamber, and during a further portion of the intake stroke, the intake valve is closed and the exhaust valve is opened to enable a portion of the exhaust gas to flow back into the combustion chamber in order to create thermally stratified layers of intake gas and exhaust gas.

A power system includes an intake arrangement and a compression ignition engine including piston-cylinder sets. Each piston-cylinder set includes: a cylinder; a piston positioned within the cylinder to form a combustion chamber in between; an intake valve configured to open and close the intake port; an exhaust valve configured to open and close the exhaust port; and a fuel injector. During an exhaust stroke, the exhaust valve is opened to enable exhaust gas to flow out; during an initial portion of an intake stroke, the intake valve is opened to enable the intake air to flow into the combustion chamber, and during a further portion of the intake stroke, the intake valve is closed and the exhaust valve is opened to enable a portion of the exhaust gas to flow back into the combustion chamber in order to create thermally stratified layers of intake gas and exhaust gas.

An engine is equipped with an engine body, a turbocharger, an exhaust gas purifier, an exhaust communication pipe. The turbocharger is connected to the engine body. The exhaust gas purifier purifies exhaust gas discharged from the turbocharger. The exhaust communication pipe connects the turbocharger with the exhaust gas purifier. The exhaust communication pipe includes: a first connection member that is connected to the turbocharger, and a second connection member that connects the first connection member with the exhaust gas purifier. A downstream end portion of the first connection member has an inner peripheral face having a cross-section of a circular shape. An upstream end portion of the first connection member has an inner peripheral face having a cross-section of an abnormal-shape that is different from the inner peripheral face of the downstream end portion.

An engine is equipped with an engine body, a turbocharger, an exhaust gas purifier, an exhaust communication pipe. The turbocharger is connected to the engine body. The exhaust gas purifier purifies exhaust gas discharged from the turbocharger. The exhaust communication pipe connects the turbocharger with the exhaust gas purifier. The exhaust communication pipe includes: a first connection member that is connected to the turbocharger, and a second connection member that connects the first connection member with the exhaust gas purifier. A downstream end portion of the first connection member has an inner peripheral face having a cross-section of a circular shape. An upstream end portion of the first connection member has an inner peripheral face having a cross-section of an abnormal-shape that is different from the inner peripheral face of the downstream end portion.

An internal combustion engine of the present invention is an internal combustion engine equipped with port injectors. Further, the internal combustion engine has an ISC passage that connects an upstream side and a downstream side of a throttle valve in an intake passage, and an ISC valve that regulates an amount of air flowing in the ISC passage. A control device of the present invention performs valve opening control that makes an opening degree of the ISC valve an opening degree larger than a reference opening degree when request torque required by the internal combustion engine is smaller than estimated torque that can be generated in the internal combustion engine, and sets a timing for fuel injection from the port injector at an opening timing of an intake valve of a cylinder in which the port injector is installed during the valve opening control.

Systems, methods, apparatus provide improved turbocharging of an internal combustion engine. A single, discrete turbocharger is affixed to each engine combustion cylinder. Turbochargers can be mounted to their associated cylinders in close proximity, thus harvesting higher energy exhaust gases from each combustion cylinder. Tip in and spool up responses can be further improved using low rotational inertia turbochargers that can operate effectively across a wide range of engine operational speeds. Controlled balancing valves between cylinder exhaust lines can deliver exhaust gases from a single cylinder selectively to multiple turbochargers in appropriate operational conditions. Moreover, multiple turbochargers' compressors can be configured in series to achieve pressurization compounding of combustion air for low RPM operation. Nesting of turbochargers relative to one another permits improved mounting of each turbocharger in close proximity to its corresponding combustion cylinder.

Methods and systems are provided for cleaning out condensate stored at a charge air cooler. In response to increased condensate accumulation at a charge air cooler, airflow through the engine is increased to purge the condensate while an engine actuator is adjusted to maintain engine torque. Combustion stability issues of engine cylinders are addressed by adjusting fueling of each cylinder individually during condensate ingestion.

A system according to the principles of the present disclosure includes an engine start module and an exhaust throttle valve control module. The engine start module determines when an engine is started based on at least one of an input from an ignition system and the speed of the engine. The exhaust throttle valve control module selectively fully closes an exhaust throttle valve in an exhaust system of the engine when the engine is started to trap exhaust gas in the exhaust system.

High pressure loop exhaust gas circulation is achieved in an exhaust system (10) of an engine (12) by providing an adjustable valve (100) in an exhaust passage (18) of the engine (12). The valve (100) is configured to control fluid flow through the passage (18) and generate pressure to drive the high pressure exhaust gas recirculation. The valve (100) includes a valve inner surface (110) that has a curvilinear profile when viewed in longitudinal cross section. An actuator (140) is connected to the valve (100), and is configured to move the valve (100) relative to the exhaust passage (18) so as to control exhaust gas pressure within the exhaust passage (18). In some embodiments, a pilot tube (280) is used in combination with the valve (100) to generate high pressure exhaust gas recirculation at the engine (12) intake.

A supercharged internal combustion engine according to the present invention includes: a compressor arranged in an intake passage through which air that is taken into a combustion chamber flows and for supercharging intake air; an EGR passage that connects an exhaust passage through which exhaust gas that is discharged from the combustion chamber flows and a compressor upstream passage; an EGR valve for opening and closing the EGR passage; an intake bypass passage for releasing gas that has been supercharged by the compressor outside a compressor downstream passage; and an ABV for opening the intake bypass passage by opening when the gas that has been supercharged by the compressor is released outside the compressor downstream passage. The intake bypass passage connects the compressor downstream passage with the EGR passage on the side that is closer to the compressor upstream passage relative to the EGR valve.