Intake holes at the opposite ends are opened and closed by first intake valves. The middle intake hole is opened and closed by a second intake valve. A control device includes an intake variable valve device. First branch channels are connected to the intake holes and produce a normal tumble flow. A second branch channel is configured such that the flow rate of intake air passing through the middle intake hole is relatively greater on the side closer to the outer periphery of the combustion chamber. Where increasing the flow coefficient is given a higher priority, a three-valve drive mode is selected. Where the strength of the normal tumble flow is enhanced, a two-valve drive mode is selected. Where production of the normal tumble flow is reduced, a one-valve drive mode is selected.

A cylinder head of an engine in which a thermal stress acting between a valve seat made of clad material and a base metal is reduced. The cylinder head comprises: an inner wall surface; a pair of intake ports arranged adjacent to each other; a valve seat formed of clad material around each intake port; a mask section formed within a predetermined range of a circumference of each intake port to protrude toward a combustion chamber; and a cavity formed between a pair of the mask sections by partially depressing the inner wall surface toward the combustion chamber.

There is provided a water cooled engine including a cylinder head with minimized thermal strain. A head water jacket includes an inter-exhaust-port-wall water channel between a first exhaust entrance port wall and a second exhaust entrance port wall. A cylinder head includes a cooling water injection passage provided at a bottom wall of the cylinder head. The cooling water injection passage is positioned on the exhaust end side, and includes a passage entrance provided on the exhaust end side, and a passage exit directed toward the inter-exhaust-port-wall water channel. An exhaust port wall includes a heat dissipation fin extending from a first exhaust entrance port wall toward an exhaust end. The space between the heat dissipation fin and a second exhaust entrance port wall forms a water channel entrance of the inter-exhaust-port-wall water channel.

A cylinder head includes a cylinder head casting having four gas exchange openings formed in a fire deck. A bolt bore and a glow plug bore extend through the cylinder head casting between an upper surface and a lower surface. The four gas exchange openings are arranged at twelve o'clock, three o'clock, six o'clock, and nine o'clock positions, circumferentially around an injector bore center axis. The bolt bore is positioned angularly between the twelve o'clock position and the three o'clock position, and the glow plug bore is positioned angularly between the three o'clock position and the six o'clock position.

Various embodiments of the present disclosure are directed to liquid-cooled cylinder heads. In one example embodiment, a cylinder head is disclosed including a component which extends into a combustion chamber, an upper cooling jacked, a lower cooling jacket, a plurality of valves arranged around the component, a plurality of cylinder head screws, an oil deck, a fire deck, a plurality of valve guides, and a fixed connection. The fixed connection is arranged from each valve guide to the component, and is a ring having at least one support. The support and the ring extend at least from the oil deck to the fire deck thereby hounding the combustion chamber, and the component is connected to the plurality of cylinder head screws.

A combustion chamber structure in which an installation hole of the injector is improved to realize a rapid combustion and to reduce an unburned hydrocarbon. In the combustion chamber, a leading end of an injector is withdrawn from an upper end of an opening of an installation hole, and an additionally expanded surface area is formed on an upper inner surface of the installation hole from a portion to which the leading end of the injector is situated. to an opening end of the installation hole. An angle between the additionally expanded surface area and a joint surface of a cylinder head is narrower than an angle between a center axis of the installation hole and the joint surface.

An internal combustion engine with a turbocharger according to an embodiment includes a cylinder block internally including a plurality of cylinders, a cylinder head disposed on top of the cylinder block, and internally including a plurality of exhaust flow passages through which exhaust air discharged from each of the plurality of cylinders flows, and the turbocharger including a rotational shaft, a turbine wheel, and a compressor wheel, the turbine wheel being disposed at one end of the rotational shaft, the compressor wheel being disposed at the other end of the rotational shaft. At least the turbine wheel of the turbocharger is arranged inside the cylinder head. The cylinder head internally includes a plurality of scroll passages for introducing the exhaust air flowing through the plurality of exhaust flow passages to the turbine wheel, the plurality of scroll passages including a first scroll passage for introducing the exhaust air from a first range in a circumferential direction of the turbine wheel to the turbine wheel, and a second scroll passage for introducing the exhaust air from a second range, which is different from the first range in the circumferential direction of the turbine wheel, to the turbine wheel.

Various embodiments of the present disclosure are directed to liquid-cooled cylinder heads. In one example embodiment, a cylinder head is disclosed including a component which extends into a combustion chamber, an upper cooling jacked, a lower cooling jacket, a plurality of valves arranged around the component, a plurality of cylinder head screws, an oil deck, a fire deck, a plurality of valve guides, and a fixed connection. The fixed connection is arranged from each valve guide to the component, and is a ring having at least one support. The support and the ring extend at least from the oil deck to the fire deck thereby bounding the combustion chamber, and the component is connected to the plurality of cylinder head screws.

An auto-ignition engine system is provided. The auto-ignition engine system includes a cylinder having an intake valve and an exhaust valve coupled thereto, an opening in a cylinder head defining a portion of the boundary of the cylinder, a glow plug heating element extending through the opening into the cylinder, an insert at least partially surrounding a glow plug heating element and coupled thereto, and an adjustment mechanism configured to alter the position of the glow plug heating element and the insert in the cylinder.

A head, for an internal combustion engine, is provided, the head using at least one plate to control the filling and emptying of the combustion chamber. The plate may be placed so that the movement of the plate may open or close the intake and/or exhaust ports. The timing of the opening and closing of the port can be controlled by a partial cutout in the plate.