Feedback control of combustion in a gas diesel dual-fuel engine (20), based on the measured cylinder pressure, has been invented. The center of combustion and pressure rise rate is controlled by manipulating the start of diesel injection and duration of diesel injection. Measurements of transient engine operation show, that the proposed controller is able to control the center of combustion and the maximum pressure rise rate. The influence of changing intake manifold pressure, changing exhaust gas recirculation rate and changing air-fuel ratio can be compensated by the controller (10). Steady state measurements show that the gas diesel dual fuel engine reaches efficiencies around 40% with stoichiometric air-fuel ratio and diesel ratios below 5%. The results have been obtained on a slightly modified production type common-rail diesel engine with four cylinders and a displacement volume of 2 liters.

A carburetor with rotary valve includes an idle adjustment needle with an eccentric hole, accordingly a special adjustment tool used for idle adjustment needle has an eccentric boss; a carburetor with rotary valve includes an idle adjustment needle with an eccentric boss, accordingly a special adjustment tool used for idle adjustment needle has an eccentric hole. The idle adjustment needle must be cooperated with the special adjustment tool to carry out the adjustment, thus non-professional user can not casually adjust the fuel oil needle without the special tool, so that the engine can be maintained in the best setting condition to ensure the engine exhaust to meet the environmental protection requirement.

An automatic transmission performs a shift-up operation when the accelerator pedal is released from a depression during a vehicle is running. An engine rotation speed immediately after the shift-up operation is predicted on the basis of the engine rotation speed and a gear ratio of the transmission after the shift-up operation. When a fuel recovery is predicted to be performed immediately after the shift-up operation, the fuel recovery is advanced such that it is performed in the inertial phase of the transmission.

A carburetor may include a body having a main bore from which a fuel and air mixture is discharged for use by an engine, a throttle valve head, a choke valve head and a flow directing feature. The throttle valve head may be carried by the body and is moveable between an idle position and a wide open position to control at least some fluid flow through the main bore. The choke valve head may also be carried by the body and is moveable between a first position and a second position to at least in part control fluid flow through the main bore. And the flow directing feature associated with the choke valve head or the throttle valve head may alter at least one of the velocity or direction of at least a portion of the fluid that flows in the main bore.

In an embodiment, a combustion control device for an engine includes: a knocking determination unit to determine occurrence of knocking of each of the cylinders; a knocking reduction unit to halt or reduce supply of gas to a cylinder in which the knocking is occurring and reduce supply of the gas to other cylinders in which the knocking is not occurring; a first recovery unit configured to recover a state where the gas is at least reduced in the cylinder in which the knocking is occurring; and a second recovery unit configured to recover a state where the gas is reduced in other cylinders within which knocking is not occurring. In embodiments, a recovery time of the first recovery unit is shorter than a recovery time of the second recovery unit, and prioritizing recovery of the cylinder in which the knocking is occurring.

Various embodiments of the present disclosure are directed towards free-piston combustion engines. As described herein, a method and system are provided for displacing a free-piston assembly to achieve a desired engine performance by repeatedly determining position-force trajectories over the course of a propagation path and effecting the displacement of the free-piston assembly based, at least in part, on the position-force trajectory. In a dual-piston assembly free-piston engine, synchronization of the two piston assemblies is provided.

Methods and systems are provided for operating a high pressure injection pump to provide each of high fixed fuel pressure at a port injection fuel rail and high variable fuel pressure at a direct injection fuel rail. Port injection fuel rail pressure can be raised above a pressure provided with a lift pump via a fuel system configuration that includes various check valves, pressure relief valves, and a spill valve positioned between an inlet of the high pressure injection pump and the port injection fuel rail. High pressure port injection may be advantageously used to provide fuel at high pressure during conditions when fuel delivery via high pressure direct injection is limited.

In at least some implementations, an engine control process includes an engine speed test and other steps. The engine speed test includes the steps of a) determining a first engine speed, b) changing the air/fuel ratio of a fuel mixture delivered to the engine, and c) determining a second engine speed after at least some of the air/fuel ratio changing event, Based at least in part on the difference between the first engine speed and the second engine speed it is determined if a change in the air/fuel ratio of the fuel mixture delivered to the engine is needed. If a change to the air/fuel ratio was indicated, the air/fuel ratio of a fuel mixture delivered to the engine is changed.

An air/fuel mixer system of a combustion chamber of a gas turbine includes at least one compressed air intake swirler, the swirler having a central axis of symmetry, and a fuel injector including an injection head having an axis of symmetry. Each injector is mounted in the corresponding swirler with aid of a guide mechanism, so that the axis of symmetry of the injection head is off-center with respect to the central axis of symmetry of the swirler. The system can reduce, or even eliminate, combustion instabilities, by injecting the fuel along a particular axis which is off-center relative to the axis of the air/fuel mixer system, inducing a flow of fuel which is no longer perfectly axially symmetrical.

An air/fuel mixer system of a combustion chamber of a gas turbine includes at least one compressed air intake swirler, the swirler having a central axis of symmetry, and a fuel injector including an injection head having an axis of symmetry. Each injector is mounted in the corresponding swirler with aid of a guide mechanism, so that the axis of symmetry of the injection head is off-center with respect to the central axis of symmetry of the swirler. The system can reduce, or even eliminate, combustion instabilities, by injecting the fuel along a particular axis which is off-center relative to the axis of the air/fuel mixer system, inducing a flow of fuel which is no longer perfectly axially symmetrical.