An engine is provided, which includes an engine body including a cylinder provided with intake and exhaust ports and intake and exhaust valves, intake and exhaust passages, a turbocharger including a turbine provided to the exhaust passage and a compressor provided to the intake passage, and a variable phase mechanism configured to change open/close timings of the intake valve while maintaining an open period of the intake valve at a 270° C.A or larger. A geometric compression ratio of the cylinder is 11:1 or higher. In a high-load range, the variable phase mechanism sets the intake valve close timing to be after an intake BDC and to make a ratio of a retarded amount of the intake closing to the geometric compression ratio be 4.58 or above and 6.67 or below, and sets the intake valve open timing to be before a close timing of the exhaust valve.

An internal combustion engine is provided, which includes a variable phase mechanism configured to change rotational phases of intake and exhaust camshafts so that a valve overlap is made. An intake cam lobe is formed such that an open period of the intake valve is 210° or larger and 330° or smaller of a crank angle. The exhaust cam lobe is formed such that, during the overlap period with the rotational phase of the intake camshaft advanced to the maximum and the rotational phase of the exhaust camshaft retarded to the maximum, an effective valve lift amount (Lift(CA)) of the exhaust valve which is a function of a crank angle from the open timing (CA.sub.IVO) of the intake valve to a middle timing (CA.sub.center) of the overlap period, an inner circumferential length (L_ex) of a valve seat, and a swept volume (V) per cylinder satisfy the following formula:

[00001]$0.015\le \frac{\mathrm{L\_ex}}{V}\times {\int }_{C{A}_{\mathrm{IVO}}}^{C{A}_{center}}\mathrm{Lif}t\left(\mathrm{CA}\right)dCA.$

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.

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.

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.

Techniques for controlling a forced-induction engine having a low pressure cooled exhaust gas recirculation (LPCEGR) system comprise determining a target boost device inlet pressure for each of one or more systems that could require a boost device inlet pressure change as part of their operation and boost device inlet pressure hardware limits for a set of components in the induction system, determining a final target boost device inlet pressure based on the determined sets of target boost device inlet pressures and boost device inlet pressure hardware limits, and controlling a differential pressure (dP) valve based on the final target boost device inlet pressure to balance (i) competing boost device inlet pressure targets of the one or more systems and (ii) the set of boost device inlet pressure hardware limits in order to optimize engine performance and prevent component damage.

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.

Engine combustion phasing control techniques utilize a trained feedforward artificial neural network (ANN) to model both base and maximum brake torque (MBT) spark timing based on six inputs: intake and exhaust camshaft positions, mass and temperature of an air charge being provided to each cylinder of the engine, engine speed, engine coolant temperature. The selected target spark timing could be adjusted based on a two-dimensional surface having engine speed and air charge mass as inputs. The target spark timing adjustment could be performed only during an initial period when the trained ANN is immature. The ANN could also be trained using dynamometer data for the engine that is artificially weighted for high load regions where accuracy of spark timing is critical.

Intake noise suppression techniques for a forced-induction engine having a low pressure exhaust gas recirculation (LPEGR) system configured to recirculate exhaust gas produced by the engine to an intake system of the engine via an EGR port comprise receiving, from a mass air flow (MAF) sensor of the engine, a MAF signal indicative of measured airflow through the intake system, detecting, based on the MAF signal, intake system conditions that are indicative of audible noise, and in response to detecting the detected intake system conditions that are indicative of audible noise, at least partially closing a differential pressure (dP) valve to mitigate or eliminate the intake system conditions and the corresponding audible noise, wherein the MAF sensor is disposed in the intake system upstream from the dP valve.

A control valve for a valve train in an internal combustion engine using four-way control logic for dynamic skip fire control of a pair of cylinders is described. A four cylinder engine can be controlled using two control valves, with each control valve controlling a pair of cylinders. Each control valve has four ports: one control port for each cylinder, a pressure inlet port, and a tank port. The control valve is used to activate or deactivate a cylinder's intake and/or exhaust valves.