Abstract: An internal-combustion engine having a pressure lubrication system according to the dry-sump principle, particularly for an opposed-cylinder engine, having a crankcase in which an oil scavenging space is constructed in the lower part feeds the lubricating oil by way of an oil return feed pump equipped with an oil scavenging pipe to an oil storage tank. The lubricating oil situated in the oil storage tank is fed by way of a main feed pump to the consuming devices. The oil storage space forming the wet sump is also integrated in the crankcase of the internal-combustion engine.

Abstract: Integrated, multi-cylinder opposed engine constructions include a unitary support structure to which cylinder liners are removeably mounted and sealed and on which crankshafts are rotatably supported. The unitary support structure includes cooling manifolds that provide liquid coolant to the cylinder liners. Exhaust and intake manifolds attached to the support structure to serve respective ports in the cylinder liner. The engine constructions may also include certain improvements in the construction of cooled pistons with flexible skirts, and in the construction of cylinders with sealing structures mounted outside of exhaust and inlet ports to control lubricant in the cylindrical interstice between the through bore and the pistons.

Abstract: Apparatus constituting part of an induction and fuel delivery system for a cylinder of a piston internal combustion engine comprising a small cyclone into which is tangentially discharged a flow of heated air to generate a sustained vortex of high rotational speed; a modulatable fuel injector delivering a flow of atomised fuel into said small cyclone wherein it underdoes flash evaporation and energetic mixing; a delivery duct connecting said small cyclone to the inlet tract of said cylinder wherein said vortex fuel-air mixture is mixed with heated induction air; and means to prevent overheating of said modulatable fuel injector.

Abstract: Disclosed is a turbocharged internal combustion engine (1) having at least one intake (8) for supplying the internal combustion engine (1) with fresh air or fresh mixture on an inlet side (10), a cylinder head (3) having at least two cylinders (3a) which are arranged along a cylinder head longitudinal axis (4) and each of which has at least one outlet opening (13) which is adjoined by an exhaust line (6) for discharging the exhaust gases out of the cylinder (3a), with the exhaust lines (6) of at least two cylinders (3a) being merged on an outlet side (11), so as to form an integrated exhaust manifold (5) within the cylinder head (3), to form an overall exhaust line (7), and at least one exhaust-gas turbocharger (2) which comprises a turbine (2a) arranged in the overall exhaust line (7) and a compressor (2b) arranged in the at least one intake (8), with the turbine (2a) having a turbine rotor, which is provided on a charger shaft (2c), and an inlet region for supplying the exhaust gas, and the compressor (2b)

Abstract: Provided is a cylinder block which includes a liner and a water jacket having a closed-deck structure in a simple configuration and which has a structure providing high rigidity and enabling easy formation at low cost. A cylinder block of the present invention includes a liner arranged on an inner circumference surface of a bored hole and a water jacket arranged on the outside of the liner in the radial direction. By a bending process of folding back an end portion of a cylinder-shaped member, a hollow portion capable of forming the water jacket is formed integrally in one end portion or both end portions of a liner portion forming the liner, and the cylinder-shaped member is enclosed with a cylinder block forming material by casting.

Abstract: A wet cylinder liner, which exhibits a cast basic body comprised of a cast iron alloy, has at least one outer surface area of which exhibits a thermal injection layer consisting of a basic iron alloy as a coating, with a layer thickness of 1 ?m to 1000 ?m.

Abstract: A method for machining a cylinder head including a cooling jacket, wherein the fire deck of the cylinder head which is in a raw state is machined by material removal in relation to a reference mark of the cylinder head. The position of the cooling jacket is used as a reference mark.

Abstract: A cooling circuit of an engine may include a water pump provided at a coolant circulation line, an engine provided with a water jacket forming a pathway through which a coolant supplied from the water pump passes, and having a coolant inflow line and a coolant exhaust line, a radiator connected to the coolant exhaust line, a thermostat selectively connecting the radiator with the water pump to control a coolant flow, a first cooling line connecting the coolant exhaust line to a heater, a first return line connecting the heater to the water pump through the thermostat, a second cooling line connecting the coolant exhaust line to a throttle body, a third cooling line connecting the throttle body to an oil cooler, and a second return line connecting the oil cooler to the first return line to guide a coolant exhausted from the oil cooler to the first return line.

Abstract: Diecasting tool for the production of a cylinder crankcase (2), comprising a salt core (4) and at least one cylinder sleeve (6), wherein the cylinder sleeve (6) comprises an upper end (8) on the cylinder head side, and a lower end (10) on the crankshaft side, and the cylinder sleeve (6) is supported on at least one center sleeve that is disposed on the diecasting tool, and the salt core (4) at least partially surrounds the cylinder sleeve (6) in the manner of a cladding, wherein the salt core (4) comprises a crown (12) that at least partially bears on one of the ends (8, 10) of the cylinder sleeve (6), and the core (4) comprising openings (14) that extend vertically beneath the end (8) of the cylinder sleeve (6) on the cylinder head side.

Abstract: An open deck type cylinder block (10) that is one embodiment of the present invention is configured as follows. A shallow portion (21) and a deep portion (22) are provided in a water jacket (20). The shallow portion (21) is provided in a portion that is comparatively far from a head bolt hole (17), while on the other hand the deep portion (22) is provided in a portion that is comparatively close to the head bolt hole (17). A hollow portion (18) in which a block outer wall is hollowed toward a cylinder center side is provided between a bottom wall portion of the shallow portion (21) and a skirt portion (14) used as a crank case.

Abstract: A vehicle engine in which a water temperature sensor can be protected against debris or foreign matter such as earth and sand, flying stones, etc., from impacting the temperature sensor without taking any protective measure for exclusive use. A vehicle engine includes a head portion of the cylinder fitted with a water temperature sensor for detecting water temperature in a water jacket. The head portion of the cylinder is provided on one side thereof with a sensor mounting hole opening directly under an upstream end opening portion of an intake port. The water temperature sensor is mounted in the sensor mounting hole. Further, the head portion of the cylinder is formed with a left-right pair of hanger bosses which are opposed to each other, with the water temperature sensor therebetween. Engine hanger brackets extend from the body frame and are firmly attached to the hanger bosses.

Abstract: A cooling apparatus for an internal combustion engine includes an engine cooling system that includes a water jacket, a radiator, and a circulation passage through which a coolant is circulated between the water jacket and the radiator, wherein the coolant is provided in the engine cooling system; a water pump that forcibly circulates the coolant provided in the engine cooling system when the water pump is operated; a reservoir tank in which the coolant is reserved, and into which gas flows from the engine cooling system while the reserved coolant flows out to the engine cooling system from the reservoir tank; and a forcible introduction portion that forcibly introduces the coolant from the reservoir tank into the engine cooling system before the internal combustion engine is started.

Abstract: The present invention is provided with one or more inserts that are inserted at the lower portion of a water jacket formed at siamese portions between cylinder bores of a cylinder block and increase the flow of cooling water at the upper portion of the water jacket, in order to provide a cooling device and an insert for a water jacket of an internal combustion engine, which is inserted at the lower portion of the water jacket formed at the siamese portions of the cylinder block to increase the flow of cooling water, improves cooling efficiency of the siamese portions of the cylinder block by inducting recirculation of the cooling water at the lower portion, and improves fuel efficiency by making the temperature uniform in the stroke direction of the piston of the cylinder block and reducing friction of the piston.

Abstract: An engine cooling apparatus includes a coolant inlet of a block water jacket formed in a cylinder block, wherein coolant is introduced into the block water jacket through the coolant inlet, a flow-directing plate that is disposed in the block water jacket at a position downstream of the coolant inlet, and that directs the coolant, which has been introduced into the block water jacket through the coolant inlet, toward a head water jacket and a control portion that controls inflow of the coolant from the head water jacket into the block water jacket.

Abstract: The invention relates to a crankcase breathing system (1) for an internal combustion engine, comprising at least one oil separating apparatus with a preliminary separator (3) and a main separator (4) arranged downstream of the same, with the preliminary separator (3) comprising a diffuser (11) between an inlet (7) and an outlet (8) which expands in the direction of flow. In order to achieve high separation rates in the simplest possible way it is provided that the preliminary separator (3) is arranged integrally with the main separator (4), with preferably the preliminary separator (3) and the main separator (4) forming a separator unit (2).

Abstract: A cooling system for internal combustion engines provides directed flows of heated or cooled coolant to various engine components and/or accessories as needed. By providing directed flows, the overall coolant flow volume is reduced from that of conventional cooling systems, allowing for a smaller capacity water pump to be employed which results in a net energy savings for the engine. Further, by reducing the overall coolant flow volume, the hoses and/or galleries required for the directed flows are reduced from those of conventional cooling systems, providing a cost savings and a weight savings. Finally, by preferably employing an impellor type water pump, the expense of an electric water pump and its associated control circuitry can be avoided. The direct flows are established by a multifunction valve which, in a preferred implementation, comprises a two-plate valve wherein each plate is operated by a wax motor.

Abstract: An oil heat exchange apparatus is provided for an internal combustion engine having cylinders aligned in a cylinder row direction. The oil heat exchange apparatus includes a cylinder head having a cylinder head coolant path through which a coolant flows, a cylinder block having a cylinder block coolant path through which the coolant flows parallel to the coolant flow through the cylinder head coolant path, and an oil passage through which oil flows. The oil passage is configured and arranged to exchange heat with the coolant flowing through both the cylinder block coolant path and the cylinder head coolant path.

Abstract: A cooling structure of an internal combustion engine includes: a cooling water introducing port provided on one end side of a cylinder block; and a water jacket provided so as to surround a cylinder bore wall, wherein cooling water is introduced from the cooling water introducing port into the water jacket, the cooling water is branched to flow to a portion on an intake side and a portion on an exhaust side of the water jacket of the cylinder block of the internal combustion engine, and the cooling water is supplied from a cylinder block side to a cylinder head side, the cooling structure of the internal combustion engine, further comprising a first regulation portion that regulates a flow of the cooling water supplied to the cylinder head side.

Abstract: A snow vehicle includes an engine, a track belt arranged on a rear side of the engine, and a cooling water path for cooling the engine, in which the engine includes a cooling water inlet portion and a cooling water outlet portion provided on a front surface side of the engine and connected with the cooling water path. The snow vehicle is capable of improving the turning ability of the vehicle, while simplifying a cooling water path and reducing the size of the structure for cooling the engine.

Abstract: A cylinder block side drain is provided in a cylinder block and a crankcase side drain is provided in a crankcase. A jacket cover is provided in an water jacket of the cylinder block. The jacket cover is pressed against the wall of the water jacket on the crankcase side. When discharging the coolant, the water jacket is opened by pushing the jacket cover inward using a coupler and the coolant is discharged to the outer side of the crankcase via the coupler.

Abstract: The present disclosure provides an engine cooling system comprising a first cooling circuit and a second cooling circuit, each of which includes a cooling unit for cooling a compressed or charge air from one or more turbochargers of the engine.

Abstract: An engine cylinder head has an exhaust manifold cast in the cylinder head. A turbocharger with a turbine body is adapted to mount directly to an exhaust outlet mounting face of the exhaust manifold. A dual level water jacket within the cylinder head has separate coolant feeds for upper and lower cooling jackets. The cooling jackets extend above and below the exhaust outlet and are connected inward of the exhaust mounting face to reduce metal temperatures of the mounting face below those of the turbocharger exhaust inlet flange. Separate cores for the upper and lower jackets are connected at coolant inlet and outlet locations at opposite ends. Intermediate core print connectors form controlled flow passages between the upper and lower jackets and exhaust ports in the cylinder head and integrated manifold. The improved cooling in these areas lowers operating temperatures in the cylinder head and obviates the need for a separate exhaust manifold.

Abstract: An engine includes an engine block with at least one cylinder, configured for a piston to be provided therein. A wet liner is provided in the cylinder such that a gap is defined between the wet liner and the cylinder. The engine block defines a coolant inlet to transport a coolant to the gap, a coolant chamber, a coolant outlet to transport the coolant from the gap to the chamber, and a supply opening to transport the coolant from the chamber to an exhaust gas recirculation system.

Abstract: The invention relates to a cylinder head (1) of an at least one-cylinder internal combustion engine with direction injection of a motor vehicle with a flame deck (2) and with an oil deck (3). An intermediate deck (4) is situated between the flame deck (2) and the oil deck (3), and at least one injector pipe (5) extends from the flame deck (2) up to the oil deck (3). The intermediate deck (4) joins a lower area of an injector pipe (5), particularly an injector dome (6) that is situated approximately centrally in the area of the flame deck (2). When viewing from the flame deck (2), the intermediate deck (4) extends outward in a concave-like manner so that the intermediate deck (4) joins a lateral wall (7) in a range of 40% to 60% of the distance between the flame deck (2) and the oil deck (3).

Abstract: A cooling system for a water-cooled internal combustion engine includes a coolant flow circuit and a coolant return passage. The coolant flow circuit includes a water pump, a water jacket having a plurality of serially connected flow passages, an oil cooler, a radiator, and a pressure-regulating valve for discharging coolant to a reservoir tank when pressure of the coolant in the coolant flow circuit reaches a predetermined target value. The coolant return passage supplies coolant from the reservoir tank to the coolant flow circuit via a check valve, which only allows coolant to flow in one direction from the reservoir tank to the coolant flow circuit.

Abstract: A water-jacket structure, for a water-cooled internal combustion engine, forms a cylinder block water jacket in a cylinder block so as to surround cylinder bores formed in the cylinder block to make cooling water flow through the cylinder block water jacket into a cylinder head water jacket formed in a cylinder head joined to the cylinder block. An upper connecting opening is formed in an upper part of the cylinder block water jacket so as to open into the cylinder head water jacket. In the cylinder block is formed a lower connecting passage opening into a lower part of the cylinder block water jacket, extending upward, and connecting to the cylinder head water jacket.

Abstract: A cooling water communication passage extending in a cylinder disposition direction is provided at a cylinder block-integrated crankcase of an engine with parallel multiple cylinders loaded by being tilted forward, and cooling water is supplied to a water jacket from the cooling water communication passage. The cooling water communication passage is adjacently disposed below the water jacket at a rear side of the cylinder bank, a water pump is placed at a crankcase side wall located at a rear side from a crankshaft, and a downstream side cooling water pipe through which the cooling water discharged from the water pump is passed is connected to an intermediate portion of the cooling water communication passage.

Abstract: The invention relates to a cooling strategy for an internal combustion engine (1) which has at least one cylinder head (2) and an associated cylinder block (3). A coolant flows in a coolant circuit (4), with at least one control element (6, 7, 8, 9) being assigned to the coolant circuit (4). During a warmup of the internal combustion engine, in successive phases, the coolant flow is conducted to separate cooling regions by the control elements (6, 7, 8, 9), wherein in an operating mode at operating temperature which follows the warmup, the coolant flow is conducted to separate cooling regions by the control elements (6, 7, 8, 9) taking into consideration the operating states of the internal combustion engine.

Abstract: The invention relates to a split cooling circuit (16) of an internal combustion engine (17), with a cylinder head water jacket (18) and an engine block water jacket (19) being provided. The split cooling circuit (16) has a pump (21), a radiator (22), a thermostat (23) and a heater core (24), with a coolant circulating in the split cooling circuit (16). To considerably reduce a warm-up phase of the internal combustion engine, the thermostat (23) is arranged to simultaneously control a flow of the coolant through the engine block water jacket (19) and through the radiator (22) when the coolant exceeds a predetermined temperature.

Abstract: A cylinder block including a block with two parts, a cylinder liner portion defining an inner wall of a water jacket and a cylinder block body defining an outer wall of the water jacket. The water jacket, which extends around the cylinders, is defined between the cylinder liner portion and the cylinder block body. A cylinder connector includes rectangular partition walls arranged in the direction cylinder liners are aligned. Each partition wall partitions adjacent cylinder lines and extends vertically downward from the bottom of the cylinder connector.

Abstract: In an internal combustion engine having a coolant circuit which comprises a first coolant line for the cylinder block and a second coolant line for the cylinder head of the engine, with the cylinder head having at least one inlet valve and at least one outlet valve per cylinder, an additional coolant duct provided in the cylinder head in close proximity to the valves is connected to the second coolant line for directly supplying coolant to the area of the cylinder outlet valves.

Abstract: An internal combustion engine includes a cylinder block formed of a metal material, a cylinder liner formed of a metal material different from that of the cylinder block, the cylinder liner being fitted onto the cylinder block, a water jacket provided between the cylinder block and the cylinder liner for retaining a coolant, and a sealing member provided in contact with the cylinder block and the cylinder liner, the sealing member preventing leakage of the coolant from the water jacket. The cylinder block and the cylinder liner have respective positioning surfaces, each of which determines a relative position against the other. The positioning surfaces are provided on the opposite side of the sealing member from the water jacket. The cylinder block and the cylinder liner are spaced apart from each other, in between the sealing member and the water jacket.

Abstract: A snow vehicle includes an engine, a track belt arranged on a rear side of the engine, and a cooling water path for cooling the engine, in which the engine includes a cooling water inlet portion and a cooling water outlet portion provided on a front surface side of the engine and connected with the cooling water path. The snow vehicle is capable of improving the turning ability of the vehicle, while simplifying a cooling water path and reducing the size of the structure for cooling the engine.

Abstract: An internal combustion engine cylinder head unit includes a number of gas flow ports extending upwardly from a fire deck. A common coolant passage extends between adjacent ones of the gas flow ports. A first coolant flow director includes a flow splitter extending downwardly into the common coolant passage so as to cause a coolant flow within the common coolant passage to remain attached upon an upper surface of the fire deck between adjacent ports. A second coolant passage runs about a radially outboard portion of the cylinder head unit, and flow in this passage is directed by a truncated bulk flow displacer extending from a rear wall of the second coolant flow passage. The second flow director causes the impingement of coolant upon both an upper surface of the fire deck and upon an outboard portion of at least one of the cylinder ports.

Abstract: A cooling structure of a cylinder block includes a water jacket portion which is provided so as to surround an entire outer periphery of the bore wall; a water jacket spacer which is inserted in the water jacket portion; and a gasket which is provided in an upper portion of the cylinder block, and which includes a hole leading to the water jacket portion. The water jacket portion is supplied with coolant. A distance between a center of the hole and an outer periphery of the cylinder block is shorter than a distance between a center of the water jacket spacer in a thickness direction and the outer periphery of the cylinder block. In the cooling structure, the cylinder block can be uniformly cooled.

Abstract: An internal combustion engine includes a cylinder head, a cylinder having an opposed surface opposed to the cylinder head and including a water jacket, which is concave in an axial direction of the cylinder, and a piston provided in the cylinder. An oil ring is provided on the piston on a side that is farthest from the cylinder head. At least a portion between a cylinder inner surface and the water jacket in the cylinder is made of a material having a higher thermal conductivity than that of iron. A bottom wall of the water jacket is positioned in the cylinder axial direction between the opposed surface of the cylinder and a lower end of the oil ring when the piston is disposed at a top dead center position.

Abstract: A cooling block forming a top wall of a combustion chamber of an internal combustion engine is formed by layering, from the outside to the inside, a casing, an upper layer block, a middle layer block, and a lower layer block. Labyrinth-shaped cooling water passages are formed on upper side faces of the three layers of blocks, and cooling water supplied from a cooling water supply passage flows from the cooling water passage on the side far from the combustion chamber to the cooling water passage on the side close to the combustion chamber, and is discharged from a cooling water discharge passage. Since the cooling water flows in a direction opposite to the direction of emission of heat of combustion from the combustion chamber, it is possible to ensure that there is sufficient difference in temperature between a cylinder head and the cooling water throughout the cooling water passages.

Abstract: An open-looped cooling system is disclosed. The cooling system typically includes a cylinder head including a first water jacket through which cooling water flows, a cooling water inlet through which the first water jacket communicates with outside, and a first cooling water outlet through which the first water jacket communicates with outside, a cylinder block including a second water jacket through which the cooling water within the first water jacket flows, the second water jacket being configured to communicate with the first water jacket, and a second cooling water outlet through which the second water jacket communicates with outside, and a thermostat configured to control a flow rate of the cooling water flowing out from the second cooling water outlet of the cylinder block based on a temperature of the cooling water.

Abstract: To simplify a coolant piping around an engine in an engine cooling structure, which has a pump mounted on a crankcase for circulating a coolant between cylinder and head jackets. A crankcase has coolant supply passages for guiding a coolant from a pump and coolant return passages for guiding a coolant delivered out of cylinder jackets. The coolant supply passages and the coolant return passages extend substantially parallel to the axis of a crankshaft. The cylinder jackets and head jackets are formed wherein the coolant supplied from the coolant supply passages returns from the cylinder jackets via the head jackets to the cylinder jackets.

Abstract: Head cooling passages are formed around intake ports and exhaust ports provided in a cylinder head, and a flow control member which controls the volume of cooling medium flowing toward the intake ports to be larger than the volume of cooling medium flowing toward the exhaust ports is provided in the vicinity of a supply port via which cooing medium is supplied.

Abstract: An engine cooling system for cooling an engine installed in an off-road vehicle includes a coolant circulating system including a thermostat held in a thermostat case, and connecting water jackets formed in the engine and a radiator. The coolant circulating system has a metal connecting pipe held by a first bracket attached to an upper end part of a first cylinder unit of the engine. The thermostat case is an individual member separate from component members of the cylinder unit, and the thermostat case is held by the first bracket. The first bracket is formed integrally with the metal connecting pipe. When the engine is a V engine having a front cylinder unit and a rear cylinder unit, the metal connecting pipe is extended between the front and the rear cylinder unit, and is held by brackets on the front and the rear cylinder unit.

Abstract: A cooling structure of a cylinder block includes a water jacket portion which is provided so as to surround an entire outer periphery of a bore wall; and a water jacket spacer which is inserted in the water jacket portion. A foreign matter collecting mechanism which collects foreign matter is provided in a bottom portion of the water jacket portion.

Abstract: A cylinder block for an internal combustion engine has a water jacket formed between cylindrically configured cylinder walls and a jacket sidewall. The cylinder walls is arranged to slideably retain pistons therein. The jacket sidewall is disposed around an external periphery of the cylinder walls. A pair of external block walls is provided on transverse sides of the cylinder block to extend almost an entire longitudinal length of the cylinder block. The external block walls are spaced apart from the jacket sidewall in a transverse direction to form gaps therebetween. The top end portions of the external block walls constitute an external flange portion of a top deck of the cylinder block. Thus, the rigidity of the top deck of the cylinder block is improved, and the sealing between the cylinder block and a cylinder head via a head gasket is improved.

Abstract: A reinforcing structure is integrally formed on a front wall of a cylinder block of shallow water jacket type. The reinforcing structure comprises mutually crossing vertical and lateral ribs. The vertical rib extends vertically between upper and lower deck portions of the cylinder block, and the lateral rib is constructed to constitute a raised ridge of a front one of jacket bottom wall. Alternatively, the reinforcing structure comprises a raised bolt boss that is integrally formed on a front one of jacket bottom walls to catch a connecting bolt used for securing a middle portion of a front cover to the front wall.

Abstract: In a water-cooled multi-cylinder vertical engine for an outboard engine system, cooling water having passed through an exhaust-manifold cooling water jacket for cooling an exhaust passage within an engine room is supplied to a cylinder-block cooling water jacket provided in a cylinder block through water supply pipes, a branching member and two upper and lower couplings. In this case, the lower coupling is locked below the center of a lowermost cylinder to minimize unevenness in flow rate of the cooling water flowing through a water jacket on opposite left and right sides of a cylinder toward a cooling water outlet provided at an upper portion thereof, thereby making uniform the distribution of the temperature around a combustion chamber, leading to an enhancement in cooling effect.

Abstract: In a cylinder head structure of a multi-cylinder engine, a head-side water jacket is provided in the cylinder head, a lateral rib extending in the engine width direction is provided at an upper face of the portion located between cylinders of bottom deck, the lateral rib bifurcates, getting around intake-side and exhaust-side connecting holes connecting the head-side water jacket with a water jacket in cylinder block, its both ends are connected with intake-port and exhaust-port walls, and its top portion is configured so as to become taller gradually from its central portion toward its outside portions. Accordingly, rigidity of the portion located between cylinders of the cylinder head can be increased in the cylinder-line direction as well as in the vertical direction, which can improve the sealing between the cylinder block and the cylinder head.

Abstract: An insert for a siamese-type internal combustion engine that separates a water jacket surrounding the cylinders into an upper portion and a lower portion. Below a predetermined engine speed coolant flows primarily in the upper water jacket portion so as to provide enhanced cooling at the upper portions of the cylinders. Above a predetermined engine speed coolant is introduced into the lower water jacket portion from the upper water jacket portion so as to provide improved cooling of the lower cylinder portions, without compromising cooling of the upper cylinder portions or the conjoined cylinder wall portions. The water jacket insert enhances coolant flow velocity at the siamesed or conjoined portions of the cylinder walls, and directs incoming initially coolant over the exhaust-side of the cylinders. Use of the insert reduces circumferential and axial intra-cylinder temperature deviations as well as inter-cylinder temperature deviations.

Abstract: A precision cooling system directs the flow of coolant to optimize coolant flow around the cylinders of an internal combustion engine. This results in lower temperatures in the upper portion of the cylinders, more uniform temperatures throughout the engine, and a lower average temperature. The precision cooling system is integrated into the construction of the water jacket distributing coolant throughout the engine and particularly around the combustion cylinders.

Abstract: An engine for a personal watercraft uses an open-looped cooling system and comprises a cylinder block having a water jacket within which cooling water flows, and a piston that reciprocates within the cylinder block, and a dimension of the water jacket in a reciprocation direction of the piston is equal to or less than a half of a reciprocation distance of the piston.

Abstract: A water jacket for a cylinder head is disclosed. The water jacket comprises a coolant flow channel formed between a coolant inlet and a coolant outlet for allowing the coolant to flow in the cylinder head. Coolant flow regulation parts are provided in the coolant flow channel for accomplishing smooth flow of the coolant between exhaust ports corresponding to respective combustion chambers, and a coolant flow distribution part is provided in the coolant flow channel for uniformly distributing flow of the coolant between the exhaust ports corresponding to the respective combustion chambers. According to the present invention, delay of the coolant flowing between the exhaust ports corresponding to the respective combustion chambers is prevented, and thus a cooling efficiency of the cylinder head is improved.