A gas feeding arrangement for feeding gas from an internal combustion engine cylinder chamber to a gas tank includes a feeding conduit assembly and a dedicated feeding valve. The feeding valve is adapted to assume an open condition in which it provides for gas transport in a direction from the cylinder chamber towards the gas tank, via the feeding conduit assembly. The gas feeding arrangement includes a one-way valve adapted to prevent gas transport from the gas tank to the cylinder chamber, via the feeding conduit assembly.

Systems and methods for managing excessive intake flow path pressure and counter flow are implemented to support enhanced engine braking applications, such as 2-stroke or 1.5-stroke engine braking implementations where the intake flow path may be exposed to excessive transient pressures in the combustion chamber during activation or deactivation of an engine brake. Intake throttle, exhaust gas recirculation (EGR) valve, intake manifold blow-off valve, compressor bypass valve, exhaust throttle, turbocharger geometry or turbocharger waste gate may be controlled to effectuate counter flow management separately or in combination. Excessive transient conditions may also be prevented or managed by sequential valve motion in which brake motion activation occurs first and then exhaust valve main event deactivation occurs second. Delay between brake activation and main event deactivation may be facilitated using mechanical and/or hydraulic implements as well as electronically.

Methods and systems are provided for operating a split exhaust engine system that provides blowthrough air and exhaust gas recirculation to an intake passage via a first exhaust manifold and exhaust gas to an exhaust passage via a second exhaust manifold. In one example, an intake valve timing, exhaust valve timing of a first set of exhaust valves coupled to the first exhaust manifold, and a position of an exhaust gas recirculation (EGR) valve in an EGR passage may be adjusted in coordination with one another in response to a condition at a compressor. The EGR passage may be coupled between the intake passage, upstream of the compressor, and the first exhaust manifold.

A vehicle having an engine system which can detect an expected compressor surge event while the compressor is operating in a stable region of a compressor map, and upon detecting the expected compressor surge event controlling one or more engine operating parameters to maintain compressor operation in the stable region of the compressor map without transgressing (or mitigating the transgression of) a compressor surge line on the compressor map which, if transgressed, may cause compressor surge to occur.

Provided is a hybrid vehicle that includes a power train including an internal combustion engine equipped with a plurality of cylinders and a drive motor unit. The drive motor unit includes an electric motor coupled to the internal combustion engine without a clutch. The internal combustion engine includes one or more decompression devices that are each installed for a subset of one or more cylinders and that operate to release compression pressure in the subset of one or more cylinders in at least one of the course of an engine stop and course of an engine start-up in which combustion is not performed. The subset of one or more cylinders are selected such that, when the one or more decompression devices are operating, compression is not produced sequentially in cylinders that are adjacent to each other in terms of the firing order.

A two-stroke opposed piston internal combustion engine including a plurality of cylinders, each cylinder being provided with a first piston and a second piston adapted to perform opposed motions in the cylinder, each cylinder being provided with at least one intake port, a communication between an air intake arrangement and the cylinder via the intake port being dependent on the position of the first piston, each cylinder further being provided with at least one exhaust port, a communication between an exhaust guiding arrangement and the cylinder via the exhaust port being dependent on the position of the second piston, at least one of the cylinders being provided with an additional port and an additional port valve, a communication between the cylinder and an additional conduit externally of the cylinder, via the additional port, being controllable with the additional port valve, the air intake arrangement including at least one intake valve for selectively reducing or inhibiting air admittance to at least one of the cylinders.

A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.

A variable compression ratio engine includes an extra chamber formed at a cylinder head, an extra valve being able to open/close the extra chamber, and an actuator being able to open/close the extra chamber by driving the extra valve.

Methods and systems are provided for providing exhaust gas recirculation to a naturally aspirated internal combustion engine. In one example, exhaust gas is recirculated to an engine intake via a dedicated scavenging manifold and a scavenging exhaust valve. The exhaust gas and fresh air that has not participated in combustion may be recirculated to engine cylinders even at high engine loads since the exhaust gas and fresh air is returned to the engine air intake at a pressure greater than atmospheric pressure.

An operating range boundary for switching a cam for driving an intake valve (drive cam) is changed in a direction of decreasing an engine load if a target EGR rate is predicted to increase across the contour line of the EGR rate. By changing the boundary, the drive cam is switched from a large cam to a small cam before an operating point is transferred from a partitioned range with a low target EGR rate to a partitioned range with a high target EGR rate.