Abstract: A rectangular vane is pivotally disposed in a rectangular cross-sectioned portion of an induction passage and operatively connected to a device such as the throttle valve of the engine. The vane accelerates the incoming charge and shapes it into a rectangular cross-sectioned jet stream having a flow component maximized in a plane normal to the cylinder axis. The induction passage in which the vane is disposed is oriented with respect to the cylinder so that the incoming jet stream enters the combustion chamber tangentially with respect to the wall of said cylinder to thereafter swirl about the combustion chamber. The strong horizontal (with respect to the cylinder axis) flow component ensures that the swirl will persist till the end of the compression stroke of the engine hence increasing the flame propagation speed which extends the lean burn limit and EGR tolerance of the engine.

Abstract: A piston has formed in the top thereof a part-spherical depression which forms part of a combustion chamber. The depression is so formed as to permit the flame front during the initial stage of combustion to reach the surface of the depression substantially at the same time, giving better conditions for efficient combustion and short combustion duration.

Abstract: An intake control device, for an internal combustion engine, to generate a strong swirl within each cylinder during light load engine operation without any substantial reduction in maximum power output. An intake port is divided by a partition wall into sub-passages extending parallel to each other, each being provided with a guide vane. The guide vanes are controlled in response to engine operating conditions.

Abstract: The temperature of an internal combustion engine is controlled in accordance with engine operating conditions such as engine load and speed by controlling the temperature of a working fluid or fluids of the engine, such as engine intake air, engine cooling water and lubricating oil. To do this there are provided fluid temperature sensing means, engine condition detecting means, a control unit to produce a control signal and means for regulating the working fluid temperature in response to the control signal so as to bring the sensed working fluid temperature closer to a predetermined reference temperature which is set as being a function of engine operating conditions. Preferably the temperature control is operated in such a manner that the working fluid temperature is high at low engine load and low at high engine load.

Abstract: An internal combustion engine is disclosed which includes a first cylinder unit always active and a second cylinder unit inactive when the engine load is below a given value. Means is provided for operating the intake and exhaust valve means associated with the first cylinder unit with relatively small valve overlap and operating the intake and exhaust valve means associated with the second cylinder unit with relatively large valve overlap.

Abstract: An engine is equipped with a fuel injector in an intake passageway immediately upstream of an intake valve. Air introduced from the intake passageway upstream of a throttle valve is ejected toward a clearance between the valve head of the intake valve and a valve seat, when the intake valve is opened. The ejected air stream strikes against the sprayed fuel injected from the fuel injector to improve the atomization of injected fuel and to form homogeneous air-fuel mixture to be inducted into the combustion chamber of the engine.

Abstract: An extra induction passage extends to an intake port for each combustion chamber to induct air, fuel or recirculated exhaust gas by utilizing vacuum in the intake port. This passage terminates at a jet-producing nozzle which is located near the end of a valve guide for an ordinary intake valve and directed towards a peripheral region of the inlet opening of the combustion chamber. Preferably, the extra induction passage extends outside of the valve guide, and a valve which acts in synchronism with the intake valve is provided to this passage or the nozzle. A gas jet from the nozzle, particularly under low-load conditions, promotes homogenization of a combustible gas mixture and causes a turbulent or swirling motion of the mixture in the combustion chamber, so that combustion proceeds rapidly and smoothly even though the mixture comprises large excess air or large amount of exhaust gas.

Abstract: The clearance volume of a combustion chamber of an internal combustion engine at the same crankangle is varied by changing the location of a small piston reciprocally disposed in a small cylinder formed in a cylinder head, which small cylinder communicates with an engine cylinder. Changing the location of the small piston is controllable through a link mechanism in response to the movement of a throttle valve for controlling the amount of intake air supplied to the combustion chamber.

Abstract: An engine is equipped with a fuel injector in an intake passageway immediately upstream of an intake valve. Air introduced from the intake passageway upstream of a throttle valve is ejected toward a clearance between the valve head of the intake valve and a valve seat, when the intake valve is opened. The ejected air stream strikes against the sprayed fuel injected from the fuel injector to improve the atomization of injected fuel and to form homogeneous air-fuel mixture to be inducted into the combustion chamber of the engine.

Abstract: Herein disclosed is an automotive spark-ignition valve-in-head internal combustion engine of the type which has main and auxiliary combustion chambers wherein combustion is initiated in the auxiliary combustion chamber and the resultant flame squirts into the main combustion chamber through a flame passageway whereby the flame fronts radiates out throughout the main combustion chamber from the outlet end of the flame passageway. The outlet end of the flame passageway is located about a "small-clearance-volume" portion of the main combustion chamber so that the flame fronts travel from the small-clearance-volume portion toward a "major-clearance-volume" portion. The small-clearance-volume portion largely corresponds to a squish-quench area in a combustion chamber of the turbulence type such as the wedge combustion chamber.

Abstract: Herein disclosed is an automotive spark-ignition valve-in-head internal combustion engine of the type which has main and auxiliary combustion chambers wherein combustion is initiated in the auxiliary combustion chamber and the resultant flame squirts into the main combustion chamber through a flame passageway whereby the flame fronts radiates out throughout the main combustion chamber from the outlet end of the flame passageway. The outlet end of the flame passageway is located about a "small-clearance-volume" portion of the main combustion chamber so that the flame fronts travel from the small-clearance-volume portion toward a "major-clearance-volume" portion. The small-clearance-volume portion largely corresponds to a squish-quench area in a combustion chamber of the turbulence type such as the wedge combustion chamber.

Abstract: Adjacent cylinders have respective exhaust ports integrated within the cylinder head to reduce the heat absorbing surface area. The common outlets are disposed as far as is practical from the neighboring head bolts.