Methods and systems for operating an engine that includes four compressors for two cylinder banks are described. In one example, output of two compressors and positions of valves are adjusted responsive to an engine air flow amount to prevent air from back flowing through a compressor. Output from the two compressors may be combined for higher engine air flow amounts.

A number of variations may include a product comprising: a bushing (100) located at a cavity (56) formed by a stationary body (46) of a valve (12), and located around a movable stem (48) of the valve (12), wherein the bushing (100) facilitates movement of the stem (48); and a seal member (102, 104) located in the cavity (46), around the stem (48), and on the inboard side of the bushing (100), wherein the seal member (102, 104) substantially prevents fluid-flow between an outer diametrical surface (76) of the stem (48) and a confronting inner diametrical surface (120, 128) of the seal member (102, 104), forming a first seal.

A boosted engine is provided, which includes an engine body formed with a combustion chamber, a spark plug, a fuel injection valve, a booster, a boost controller, and a control unit including an operating range determining module and a compression end temperature estimating module. In a high load range, the fuel injection valve and the spark plug are controlled so that a mixture gas inside the combustion chamber starts combustion through flame propagation by ignition of the spark plug, and unburned mixture gas then combusts by compression ignition, and the boost controller is controlled to bring the booster into a boosting state. When a gas temperature inside the combustion chamber exceeds a given temperature at CTDC, the fuel injection valve is controlled so that a fuel injection end timing occurs on a compression stroke, and the spark plug is controlled so that the mixture gas is ignited after CTDC.

An engine control device controls an engine including a turbo-supercharger, a waste gate valve, an air-bypass valve, and a high-pressure fuel system. The engine control device includes: an air-bypass valve control unit and an abnormality detection unit. The air-bypass valve control unit controls the air-bypass valve. The abnormality detection unit detects an abnormality in the high-pressure fuel system. The air-bypass valve control unit increases an opening degree of the air-bypass valve in accordance with detection of the abnormality by the abnormality detection unit.

A propulsion assembly for a motor vehicle with an internal combustion engine comprising at least one movable member, a turbocharger comprising a turbine adapted to expand exhaust gases to generate work and a first compressor adapted to compress air by means of the work generated by the turbine, an intake line connecting an outlet of the first compressor to an intake manifold of said engine to supply compressed air from the first compressor to said engine, wherein the intake line comprises a second compressor, which in turn comprises a compressor shaft rotatable about a first axis and is configured to further compress the compressed air from the first compressor via a rotation of the compressor shaft. The propulsion assembly further comprises mechanical transmission means configured to couple the movable member to the compressor shaft, thereby determining a transmission of motion from the movable member to the compressor shaft.

A control device according to the present invention determines whether a demand load demanded of an engine exceeds a load threshold. The control device starts an electric motor if the demand load exceeds the load threshold. If the demand load is equal to or less than the load threshold, the control device performs control such that the degree of opening of an on-off valve increases monotonically with respect to the demand load. The control device switches the on-off valve from an open state to a closed state when the electric motor starts.

This control device starts, an electric motor on the basis of a drive signal. After starting of the electric motor, the control device switches a bypass valve from an open state to a closed state.

In an engine system 10 having a high-pressure stage turbocharger 11 and a low-pressure stage turbocharger 12 provided in series, a control device 40 is configured to perform control such that when switching from multi-stage supercharging Cm to single-stage supercharging Cs, after only the exhaust bypass valve 23 is opened, and thereafter, an intake bypass valve 21 is opened later than at a timing at which the exhaust bypass valve 23 is opened.

Methods and systems are provided for operating an electric supercharger as an on-board air pump and/or vacuum pump. During conditions when a vehicle is not being propelled and the vehicle engine is idling, a portion of an air intake passage is sealed and the supercharger is operated to deliver compressed air into the sealed portion. Compressed air can then be picked up directly from the sealed portion for use in tire inflation, or picked up via an ejector to provide vacuum for vacuum actuators.

The present disclosure provides a boosting control method of an engine for cylinder de-activation (CDA). The method includes: a CDA operable area confirming step of determining, by a controller based on a driving state of the engine, whether the CDA is in an operable area after the engine starts; an actual boosting deriving step of deriving a total target boosting from the controller and calculating the desired actual boosting; a supercharger operable area confirming step of determining, by the controller, whether the supercharger is in the operable area; a supercharger target rotation speed deriving step of deriving, by the controller, a target rotation speed of the supercharger; and a supercharger passage opening step of closing a bypass valve to open a supercharger passage.