A spark ignition type engine enabling engine startability to be favorable is provided. The spark ignition type engine includes a main intake-air passage; a throttle valve of the main intake-air passage; a bypass intake-air passage bypassing the throttle valve; an ISC valve of the bypass intake-air passage; and an electronic control device that controls an engine speed by adjusting an opening degree of the ISC valve, in which when the engine is started, cranking is performed at a cranking opening degree at which the ISC valve is narrowed by a predetermined amount from a fully opened state by control of the electronic control device, so that an intake-air negative pressure is generated on an intake-air downstream side of the ISC valve.

A spark ignition type engine enabling engine startability to be favorable is provided. The spark ignition type engine includes a main intake-air passage; a throttle valve of the main intake-air passage; a bypass intake-air passage bypassing the throttle valve; an ISC valve of the bypass intake-air passage; and an electronic control device that controls an engine speed by adjusting an opening degree of the ISC valve, in which when the engine is started, cranking is performed at a cranking opening degree at which the ISC valve is narrowed by a predetermined amount from a fully opened state by control of the electronic control device, so that an intake-air negative pressure is generated on an intake-air downstream side of the ISC valve.

The invention relates to a torque limiting device in a torque bearing connecting structure between a gearbox and a stationary structure in a gas turbine engine, wherein the torque limiting device comprises a mechanical fuse in the connection structure comprising an at least partially circumferential weakening of the material. The invention also relates to a gas turbine engine.

Provided are a motor capable of forcibly rotating an engine when the engine is started; and an electric supercharger disposed in an intake passage and driven by electric energy. When the engine is started in a state that a temperature inside a cylinder is equal to or higher than a predetermined first reference temperature, the electric supercharger is driven after an assist motor is driven. When the engine is started in a state that a temperature inside the cylinder is lower than the first reference temperature, the assist motor is driven after the electric supercharger is driven.

The invention relates to a torque limiting device in a torque bearing connecting structure between a gearbox and a stationary structure in a gas turbine engine, wherein the torque limiting device comprises a mechanical fuse in the connection structure comprising an at least partially circumferential weakening of the material. The invention also relates to a gas turbine engine.

Methods and systems are provided for improving engine startability during cold-start conditions, when operating with gasoline fuels, alcohol fuels, or blended fuels. In one example, a method of engine cold-start control may include initiating fuel injection for cylinder combustion with manifold pressure lowered via intake throttle adjustments. The manifold pressure is lowered based on an optimization between cylinder charge reduction and improved fuel boiling at the lower pressure.

Methods and systems are provided for improving engine startability during cold-start conditions, when operating with gasoline fuels, alcohol fuels, or blended fuels. In one example, a method of engine cold-start control may include initiating fuel injection for cylinder combustion with manifold pressure lowered via intake throttle adjustments. The manifold pressure is lowered based on an optimization between cylinder charge reduction and improved fuel boiling at the lower pressure.