A muffler is detachably attached to an engine. A catalyst for purifying exhaust gas is provided upstream of the muffler, and a secondary air valve for supplying air to an exhaust passage is provided upstream of the catalyst. The catalyst and the secondary air valve are integrally unitized. A catalyst unit including the catalyst and the secondary air valve is provided between the engine and the muffler.

An engine includes a block defining at least one cylinder and a cylinder head received on the block. The cylinder includes a casting defining an exhaust port in fluid communication with the cylinder and an integrated exhaust manifold. The integrated exhaust manifold has an exhaust runner defined by the casting and extending from the exhaust port to an outlet defined on an outer surface of the casting. The casting includes a protrusion extending into the exhaust runner such that a raised dimple is disposed on a sidewall of the exhaust runner. The casting further defines a sensor bore extending towards the protrusion such that the sensor bore and the protrusion have a common centerline. A temperature sensor is disposed in the sensor bore and has a sensing element arranged in proximity to the protrusion such that the sensing element reads a temperature of the protrusion.

Systems for an integrated exhaust manifold cylinder head are provided. In one example, an exhaust manifold for a vehicle includes a plurality of exhaust runners coupling a plurality of cylinder exhaust gas outlet ports to an exhaust exit port, the plurality of exhaust runners forming at least a first exhaust passage and a second exhaust passage at the exhaust exit port; an upper cooling jacket positioned vertically above the first exhaust passage; a lower cooling jacket positioned vertically below the second exhaust passage; and a central cooling jacket positioned vertically below the first exhaust passage and vertically above the second passage.

An automobile vehicle engine exhaust system with integrated exhaust gas recirculation portion includes a cylinder head having a first exhaust passage internal to the cylinder head. The first exhaust passage is split within the cylinder head into a dedicated exhaust passage opening out of the cylinder head via a dedicated exhaust port, and an exhaust gas recirculation (EGR) exhaust passage opening out of the cylinder head via an EGR exhaust port. A valve assembly is operated to open one of the dedicated exhaust port or the EGR exhaust port while closing the other one of the dedicated exhaust port or the EGR exhaust port.

An exhaust manifold assembly with a thermal barrier coating for an opposed-piston engine reduces heat rejection to coolant, while increasing exhaust temperatures, fuel efficiency, and quicker exhaust after-treatment light-off. The exhaust manifold assembly can include a coating on the inside surface of the manifold assembly. The coated exhaust manifold assembly can ensure structural robustness of the exhaust manifold assembly over a larger range of operating temperatures.

A cylinder head arrangement for an internal combustion engine is provided. The cylinder head includes an integrated exhaust manifold having first and second exhaust passages to collect exhaust gas from respective cylinders to direct the exhaust gas to respective outlets of the cylinder head. The cylinder head includes a flange where the first and second outlets exit the cylinder head for connection with a turbocharger.

The disclosure provides a multi-cylinder internal combustion engine having a cylinder head that includes an exhaust port capable of cooling exhaust gas more effectively. The cylinder head includes: a first ceiling surface that closes a first cylinder having a cylinder axis separated from an exhaust opening by a first distance; a second ceiling surface that closes a second cylinder having a cylinder axis separated from the exhaust opening by a second distance shorter than the first distance; and an exhaust port that extends toward the exhaust opening from two port openings which are open to a combustion chamber for each individual cylinder. The exhaust port individually extends from each of the port openings and merges with each cylinder outside a joining surface of the cylinder head for a cylinder block in a plan view.

A cylinder head arrangement for an internal combustion engine is provided. The cylinder head includes an integrated exhaust manifold having first and second exhaust passages to collect exhaust gas from respective cylinders to direct the exhaust gas to respective outlets of the cylinder head. The cylinder head includes a flange where the first and second outlets exit the cylinder head for connection with a turbocharger.

The disclosure provides a multi-cylinder internal combustion engine having a cylinder head that includes an exhaust port capable of cooling exhaust gas more effectively. The cylinder head includes: a first ceiling surface that closes a first cylinder having a cylinder axis separated from an exhaust opening by a first distance; a second ceiling surface that closes a second cylinder having a cylinder axis separated from the exhaust opening by a second distance shorter than the first distance; and an exhaust port that extends toward the exhaust opening from two port openings which are open to a combustion chamber for each individual cylinder. The exhaust port individually extends from each of the port openings and merges with each cylinder outside a joining surface of the cylinder head for a cylinder block in a plan view.

A muffler is detachably attached to an engine. A catalyst for purifying exhaust gas is provided upstream of the muffler, and a secondary air valve for supplying air to an exhaust passage is provided upstream of the catalyst. The catalyst and the secondary air valve are integrally unitized. A catalyst unit including the catalyst and the secondary air valve is provided between the engine and the muffler.