Systems, apparatus, and methods are disclosed that include a divided exhaust engine with at least one pair of primary EGR cylinders and a plurality of pairs of non-primary EGR cylinders. The pair of primary EGR cylinders can be connected to an intake with an EGR system that lacks an EGR cooler. In another embodiment, the cylinder pairs include exhaust flow paths that join in the cylinder head to form a common exhaust outlet for each cylinder pair in the cylinder head that is connected directly to the EGR system or to the exhaust system without an exhaust manifold.

An arrangement of exchangers for marinization of a marine engine, including an engine block with in-line cylinders or cylinders in a V, cooled by a cooling fluid, at least one turbocompressor with a hot chamber connected to an outlet and a cold chamber connected to the cylinders of the engine block, a reverser including a housing and containing oil, wherein the arrangement includes: a radiator hose for supplying cooling water, a turbocompressor exchanger, an engine exchanger, a reverser exchanger, a radiator hose for discharging cooling water toward an outlet of combustion gases, downstream from the hot chamber of the at least one turbocompressor,
with these three exchangers being placed in this order and inserted in the circulation direction of the water between the radiator hose for supplying the cooling water and the radiator hose for discharging this same cooling water.

An internal combustion engine has a plurality of cylinders and transmission arranged adjoining the engine. If designating an average height of a combustion chamber in a region inside from a virtual cylindrical surface passing through center of a valve body of an intake valve and extending in a circumferential direction of each cylinder when a piston is at top dead center, as center height, and designating average of a height of the combustion chamber in a region outside from the virtual cylindrical surface when the piston is at top dead center, as peripheral height, the combustion chambers form a center height of a transmission side cylinder positioned most to the transmission side among the plurality of cylinders is higher than center heights of usual cylinders including one cylinder other than the transmission side cylinder and a peripheral height at the transmission side cylinder lower than peripheral heights of usual cylinders.

Exhaust systems are described. In examples, an exhaust flow path couples exhaust ports with one or more turbochargers of an engine. The exhaust flow path may have a portion flowing through a cylinder head (e.g., couplable to the exhaust ports) and a portion flowing through an exhaust manifold (couplable to the cylinder head and the turbocharger(s)). The flow paths may be shaped to reduce the sharpness of turns between the exhaust ports and the turbocharger(s). For example, curves along the flow path may be less than 90 degrees or have a minimum curve radius, which may vary along the flow path. Additionally, at least two, independent flow paths may exist between the exhaust ports and the turbocharger(s). The cross-sectional shape of any part of the flow path may be elliptical, including at inlets and outlets.

In an embodiment, an internal combustion engine comprises a plurality of cylinders, each of the plurality of cylinders comprising at least one intake deactivator operatively connected to at least one intake valve and at least one exhaust deactivator operatively connected to at least one exhaust. An intake deactivator controller is operatively connected to the intake deactivators associated with at least two cylinders of the plurality of cylinders, and an exhaust deactivator controller is operatively connected to the exhaust deactivators associated with the at least two cylinders. In another embodiment, only a single deactivator controller is operatively connected to both the intake deactivators and to the exhaust deactivators associated with the at least two cylinders of the plurality of cylinders.

According to the invention, a method is provided of operating a combustion engine comprising more than three cylinders with cylinder valves that are operated in a cycle of fuel intake, pressurizing, firing and exhaust strokes. The method comprises carrying out the cycle for at least two cylinders in a simultaneous operation; and having the simultaneously operated cylinders to exhaust in a manifold that couples to a single turbine.

Techniques for controlling a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system comprise determining a desired differential pressure (dP) at an inlet of a boost device based on an engine mass air flow (MAF) and a speed of the engine, wherein the engine further comprises a dP valve disposed upstream from an EGR port and a throttle valve disposed downstream from the boost device, determining a desired EGR mass fraction based on at least the engine MAF and the engine speed, determining a maximum throttle inlet pressure (TIP) based on the engine speed, the desired EGR mass fraction, and a barometric pressure, and performing coordinated control of the dP valve and the throttle valve based on the desired dP and the maximum TIP, respectively, thereby extending EGR operability to additional engine speed/load regions and increasing engine efficiency.

An internal combustion engine includes a crankcase that defines a crank chamber, a crankshaft that has a crank housed in the crank chamber and is rotatably supported on the crankcase, a cylinder block that is joined to the crankcase and defines a plurality of cylinders in a horizontally-opposed arrangement, a to-be-detected body that rotates integrally with the crankshaft, and a detection sensor that extends through the crankcase from an upper face of the crankcase, is made to face a trajectory of the to-be-detected body, and generates a pulse signal in response to movement of the to-be-detected body. Thus, in a so-called horizontally-opposed internal combustion engine, a structure for disposing a detection sensor that can detect the angular velocity of a crankshaft with high precision is provided.

A multi-cylinder engine having an engine body with a cylinder head is provided. The engine includes first and second cylinder groups, each having a plurality of independent exhaust passage parts provided to the cylinder head and connected to cylinders of the first and second cylinder groups, respectively, and first and second collective exhaust passage parts collecting the first and second pluralities of independent exhaust passage parts at a location downstream in an exhaust gas flow direction, and having an opening formed in the side surface part of the cylinder head, first and second exhaust-pipe parts each connected to the openings of the first and second collective exhaust passage parts, respectively, an exhaust gas recirculation (EGR) passage connected at one end to the first exhaust passage group and connected at the other end to an intake passage, and an exhaust gas temperature sensor provided to the first exhaust-pipe part.

An outboard motor (10) includes a V-engine (20) having a left bank (BL) and a right bank (BR) extending obliquely toward a rear left side and a rear right side, respectively, relative to a crankshaft (21) extending in a vertical direction. An intake device (18) is provided between the left bank and the right bank, and catalyst devices (62L, 62R) that treat exhaust gas are disposed rearward of cylinder heads (24L, 24R) of the left bank and the right bank.