Methods and systems are provided for reducing torque pulsations during hybrid engine shutdown and restarts. A valve actuating mechanism may be actuated to operate an engine with a selected valve lift profile during engine restart and shutdown events that is distinct from the valve lift profile applied during cylinder combustion. The selected valve lift profile reduces cylinder pressure during engine shutdown and restarts.

A method of controlling intake and exhaust cam phase in an internal combustion engine includes sensing an engine speed and an engine load of the internal combustion engine, sensing or estimating a wall temperature of a cylinder of the internal combustion engine, utilizing the engine speed and the engine load in one or more lookup tables based on the cylinder wall temperature to determine intake phaser constraint values and exhaust phaser constraint values for cold operation of the internal combustion engine, and transitioning the intake phaser constraint values and the exhaust phaser constraint values for cold operation to intake phaser constraint values and exhaust phaser constraint values based on one or more lookup tables for normal hot operation of the internal combustion engine.

A control apparatus for an internal combustion engine includes an electronic control unit that is configured to perform an operation of making a lift amount of a specific valve corresponding to one of either intake ports or exhaust ports for a specific cylinder in which an amount of condensate water produced in the port or flowing into the port is larger than in the other cylinders when the engine is stopped, in a case where production of condensate water in the ports or inflow of condensate water into the ports is predicted.

A compression-ignition low octane gasoline engine. The engine uses low octane gasoline and a compression-ignition method, does not require a spark plug, and compared with ordinary gasoline engines, increases thermal efficiency by approximately 40% and reduces green-house effects caused by emissions by approximately 45%. The compression-ignition of the low octane gasoline engine is a diffusion charge compression-ignition, differing from a homogeneous charge compression-ignition. The compression ratio in a cylinder can be 14 to 22, while an ordinary gasoline engine has a compression ratio of 7 to 11. The low octane gasoline engine has a simple structure, easy combustion control, a low noise level, and a low failure rate. As the low octane gasoline can be free of aromatic hydrocarbons, and not require the addition of antiknock agents such as MTBE and MMT, the present novel gasoline engine is a highly efficient, clean, and environmentally friendly internal combustion engine.

A system and method of controlling an angular position of a camshaft relative to an angular position of a crankshaft includes detecting rotational movement of an electric motor output shaft controlling a camshaft phaser; detecting rotational movement of the crankshaft; determining the relative difference between the rotational movement of the electric motor output shaft and the rotational movement of the crankshaft; and determining whether the angular position of the camshaft relative to the angular position of the crankshaft is advancing, retarding, or remaining constant.

An internal combustion engine system and methods of use are provided. The internal combustion engine system may comprise an engine chamber with a piston, and one or more of the following, configured to enable a negative valve overlap (NVO) mode of operation in which an intake valve opening (IVO) timing is later than an exhaust valve closing (EVC) timing: a continuously variable valve duration (CVVD) mechanism for both an intake valve and an exhaust valve; a dual CVVD and continuously variable valve timing (CVVT) mechanism for both the intake valve and the exhaust valve; and a cam system. The internal combustion system may comprise a fuel delivery system comprising one or more of a direct injector and a port fuel injector; and may comprise an ignition system.

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, one or more valves of a set of first exhaust valves coupled to the second exhaust manifold may be deactivated in response to select engine operating conditions, while maintaining active all valves of a set of second exhaust valves coupled to the first exhaust manifold. The select engine operating conditions may include one or more of a deceleration fuel shut-off condition, a part throttle condition, and a cold start condition.

It is intended to, when abnormality in either one of two rotation detection sections with different detection frequencies occurs, quickly and highly accurately detect the abnormality to favorably deal with abnormality occurring during low engine rotation. It is determined that abnormality is present in the rotation phase detection section, when an absolute value of difference between an actual VTC angle detected by a rotation phase detection section and an integrated value of a VTC change angle detected by motor rotation sensor 201 with the higher detection frequency than the frequency of detection of the actual VTC angle by the rotation phase detection section is equal to or greater than a predetermined value.

An engine control device controls a cylinder direct fuel injection type spark ignition engine provided with a fuel injection valve configured to directly inject fuel into a cylinder and an ignition plug configured to perform spark ignition for a gas mixture inside the cylinder. The engine control device executes a catalyst warm-up operation for retarding an ignition timing, during a compression stroke of the fuel injection timing, in a case where it is necessary to warm up an exhaust gas purifying catalyst inserted into an exhaust passage. In addition, the engine control device increases a valve overlap period as a piston crown surface temperature increases during execution of the catalyst warm-up operation.

A method for operating a combustion engine after a cold start, the combustion engine including a supercharger device, a plurality of combustion chambers, a fuel-injection device injecting into each of the combustion chambers, and a gas-exchange valve control device that controls gas-exchange valves in a variable manner. A rich fuel-air mixture is generated in the combustion chambers, and the combustion-chamber charges are ignited in a retarded manner. Following the cold start, the combustion engine is operated with first valve overlaps that are greater than in a warm combustion engine. A first exhaust valve of a first combustion chamber is initially closed at such a late point that its opening duration overlaps with the opening duration of a second exhaust valve of a second combustion chamber that directly follows the first combustion chamber in the ignition sequence and that discharges into the same exhaust manifold as the first combustion chamber.