Internal combustion engine cooling system

Abstract

An engine has a cylinder block that defines a cooling circuit with an inlet passage located next to a first end of the block. This inlet passage is flow-connected to a continuous open channel positioned between a side wall of the block and several cylinders arranged in a row. The channel intersects a block face and extends along each of the cylinders. The channel is configured to direct coolant to a cylinder head.

Description

TECHNICAL FIELD

[0001] Various embodiments relate to a cooling system for an internal combustion engine. BACKGROUND

[0002] Internal combustion engines typically have an associated cooling system for thermal management and controlling the temperature of the engine and engine components during operation. The cooling system, which may include a liquid coolant, can be used to cool both the cylinder block and the cylinder head components.

[0003] JP 2009 - 216 063 A discloses an engine according to the preamble of claim 1 or 8 and a method for cooling an engine according to the preamble of claim 17.

[0004] DE 10 2014 222 734 A1 discloses an internal combustion engine with a coolant channel surrounding the combustion chambers. US Pat. No. 4,665,867 A discloses a cooling device for a cylinder block.

[0005] The object of the invention is to provide an alternative and more compact coolant supply system for the generic engines or the generic method. SUMMARY

[0006] According to the invention, an engine having the features of claim 1, an engine having the features of claim 8, and a method for cooling an engine having the features of claim 17 are proposed. Advantageous embodiments of the invention are specified in the dependent claims and the following description. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 illustrates a schematic representation of an internal combustion engine configured to implement the disclosed embodiments; Fig. 2 illustrates a plan view of a cylinder block for an engine with a cooling system according to an embodiment; Fig. 3 shows a side sectional view of the engine of Fig. 2; Fig. Figure 4 shows another side section view of the engine of Fig. 2; and Fig. Figure 5 shows yet another side section view of the engine of Fig. 2. DETAILED DESCRIPTION

[0007] As required, detailed embodiments of the present disclosure are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary and may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. The specific structural and functional details disclosed herein are therefore not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art how to variously employ the present invention.

[0008] Fig. 1 shows a schematic representation of an internal combustion engine 20. The engine 20 has a plurality of cylinders 22, and one cylinder is shown. In one example, the engine 20 has the cylinders 22 in a series arrangement, and the cylinders 22 may, in another example and as shown in Fig. 2 shown below. The engine 20 has a combustion chamber 24 associated with each cylinder 22. The cylinder 22 is formed by cylinder walls 32 and a piston 34. The piston 34 is connected to a crankshaft 36. The combustion chamber 24 is in fluid communication with the intake manifold 38 and the exhaust manifold 40. An intake valve 42 controls flow from the intake manifold 38 into the combustion chamber 24. An exhaust valve 44 controls flow from the combustion chamber 24 to the exhaust manifold 40. The intake and exhaust valves 42, 44 can be operated to control engine operation in various ways known in the art.

[0009] A fuel injector 46 directs fuel from a fuel system directly into the combustion chamber 24, making the engine a direct-injection engine. A low-pressure or high-pressure fuel injection system may be used with the engine 20, or in other examples, a port injection system may be used. An ignition system includes a spark plug 48 controlled to provide energy in the form of a spark to ignite a fuel-air mixture within the combustion chamber 24. In other embodiments, other fuel delivery systems and ignition systems or techniques may be used, including compression ignition.

[0010] The engine 20 includes a controller and various sensors configured to provide signals to the controller for use in controlling air and fuel delivery to the engine, ignition control, power and torque output from the engine, and the like. Engine sensors may include, among others, an oxygen sensor in the exhaust manifold 40, an engine coolant temperature sensor, an accelerator pedal position sensor, an engine manifold pressure (MAP) sensor, an engine position sensor for the position of the crankshaft, a mass air flow sensor in the intake manifold 38, a throttle position sensor, and the like.

[0011] In some embodiments, the engine 20 is used as the sole power source in a vehicle, such as a conventional vehicle or a stop / start vehicle. In other embodiments, the engine may be used in a hybrid vehicle, where an additional power source, such as an electric motor, is available to provide additional power to propel the vehicle.

[0012] Each cylinder 22 may operate in a four-stroke cycle, including an intake stroke, a compression stroke, an ignition stroke, and an exhaust stroke. In other embodiments, the engine may operate in a two-stroke cycle. During the intake stroke, the intake valve 42 opens and the exhaust valve 44 closes, while the piston 34 moves from the top of the cylinder 22 to the bottom of the cylinder 22 to draw air from the intake manifold into the combustion chamber. A position of the piston 34 at the top of the cylinder 22 is generally known as top dead center (TDC). A position of the piston 34 at the bottom of the cylinder is generally known as bottom dead center (BDC).

[0013] During the compression stroke, the intake and exhaust valves 42, 44 are closed. The piston 34 moves from the bottom to the top of the cylinder 22 to compress the air in the combustion chamber 24.

[0014] Fuel is then introduced into the combustion chamber 24 and ignited. In the illustrated engine 20, the fuel is injected into the chamber 24 and is then ignited using the spark plug 48. In other examples, the fuel may be ignited by auto-ignition.

[0015] During the combustion stroke, the ignited fuel-air mixture expands within the combustion chamber 24, causing the piston 34 to move from the top of the cylinder 22 to the bottom of the cylinder 22. The movement of the piston 34 causes a corresponding movement in the crankshaft 36 and provides a mechanical torque output from the engine 20.

[0016] During the exhaust stroke, intake valve 42 remains closed and exhaust valve 44 opens. Piston 34 moves from the bottom of the cylinder to the top of cylinder 22 to remove exhaust gases and combustion products from combustion chamber 24 by reducing the volume of chamber 24. The exhaust gases flow from combustion cylinder 22 to exhaust manifold 40 and to an aftertreatment system, such as a catalytic converter.

[0017] The positions and timing of the intake and exhaust valves 42, 44 as well as the fuel injection timing and the ignition timing can be varied for the different engine cycles.

[0018] The engine 20 includes a cooling system 70 for removing heat from the engine 20. The amount of heat removed from the engine 20 can be controlled by a cooling system controller or the engine controller. The cooling system 70 can be integrated into the engine 20 as one or more cooling circuits. The cooling system 70 can contain water or another coolant as the working fluid. In one example, the cooling system 70 has a first cooling circuit 84 in the cylinder block 76, 100 and a second cooling circuit 86 in the cylinder head 80, 200, with the circuits 84, 86 being in fluid communication with each other, as described below with reference to Fig. 2. The coolant, such as water, in the cooling system 70 flows from a high-pressure region to a low-pressure region.

[0019] The cooling system 70 includes one or more pumps 74 that supply fluid to the cooling passages in the circuits 76, 100, 86. The cooling system 70 may also include valves, thermostats, and the like for controlling the flow or pressure of the coolant or for directing the coolant within the system 70. At least some of the cooling passages in the cylinder block 76, 100 may form a cooling jacket surrounding and adjacent to one or more of the cylinders 22 and the bore bridges formed between the cylinders 22. Similarly, at least some of the cooling passages in the cylinder head 80, 200 may be adjacent to one or more of the combustion chambers 24 and cylinders 22 and the bore bridges, exhaust valves, exhaust valve seats, and other components formed between the combustion chambers 24.

[0020] The cylinder head 80, 200 is connected to the cylinder block 76, 100 to form the cylinders 22 and combustion chambers 24. A cylinder head gasket 78 is positioned between the cylinder block 76, 100 and the cylinder head 80, 200 to seal the cylinders 22. The gasket 78 may also include various slots, passages, or the like for fluidly connecting the jackets 84, 86. The cooling system 70 may further include various heat exchangers, such as a radiator 82, wherein heat from the coolant is released to the ambient environment, or the coolant is used to cool or heat other engine or vehicle components and / or working fluids.

[0021] Fig. 2-5 illustrate an example of the present disclosure shown in Fig. 1. The example shown provides a flow circuit for managing the thermal gradients of the cylinder block and cylinder head components and the operating temperature of the engine and its components. A feed runner or conveyor trough is provided in the cylinder block deck surface and located outboard of the head bolt pillars of the cylinder block. The feed runner is configured to distribute and deliver coolant to all cylinders in the cylinder head substantially evenly and essentially acts as an internal manifold. The cooling strategy of flowing from the cylinder block to the cylinder head via the feed runner is effective in that it provides a cast-in feature of the cylinder block that distributes the coolant to crossflow inlets on the cylinder head on the exhaust side of the engine.The upward branch flow into the cylinder head allows for controlled coolant flow to high-temperature areas of the cylinder head, such as the exhaust ports and exhaust valve seats. The intake duct or channel allows the engine to utilize a parallel split-flow cooling strategy, where part of the coolant in the cylinder block is used to cool the cylinder block and another part is directed to the cylinder head, as well as a cross-flow strategy in the cylinder head.

[0022] Fig. 2 illustrates a plan view of a cylinder block 76, 100 for an internal combustion engine. In one example, the cylinder block 76, 100 may be coupled to the engine 20 of Fig. 1. As shown, the cylinder block 76, 100 includes four cylinders 102 arranged in a co-cast in-line configuration along a longitudinal axis 104 of the cylinder block 76, 100, although other numbers of cylinders 102 and arrangements for the cylinders are contemplated for other embodiments.

[0023] The cylinder block 76, 100 has a first end wall 110, a second opposite end wall 112, a first side wall 114, a second side wall 116, and a top surface 118. The first side wall 114 may be located on an intake side of the engine or the side of the engine associated with the air intake and intake valves. The second side wall 116 may be located on an exhaust side of the engine or the side of the engine associated with the cylinder exhaust gases and exhaust valves. The top surface 118 of the cylinder block 76, 100 is configured to mate with a corresponding top surface of the cylinder head, and a cylinder head gasket may be positioned therebetween to seal the cylinders 102. The cylinder head gasket is Fig. 2 not shown; however, Fig. 2 shows the passages 120 and slots in the cylinder head gasket, which are discussed below, in dashed lines.

[0024] The engine has a cooling system 130 comprising a cooling circuit 132 in the cylinder block 76, 100 of cooling passages formed integrally in the cylinder block 76, 100, for example, during a casting process, molding process, or by machining the cylinder block 76, 100 after formation. The cooling system 130 may be connected to the cooling system 70 in Fig. 1 correspond.

[0025] The cooling circuit 132 includes an inlet passage 134 adjacent the first end 110 of the cylinder block 76, 100. The inlet passage 134 is fluidly connected to a continuous open intake channel 136 or trough in the cylinder block 76, 100. The open channel or intake channel 136 is positioned between the sidewall 116 and the cylinders 102. The intake channel 136 is an open intake channel 136 because it is defined by the cylinder block with a bottom 138 and a sidewall 140 and is open along the top surface 118. The intake channel 136 may be provided as a "cast-in" feature of the cylinder block 76, 100. The inlet channel 136 intersects the deck surface 118 and extends along each cylinder 102 of the cylinder block 76, 100. The inlet channel 136 has a first end 142 located adjacent to one of the end cylinders 144 and a second end 146 located adjacent to the other end cylinder 144.The inlet channel 136 has an elongated shape and can run parallel or substantially parallel to the longitudinal axis 104. The inlet channel 136 is dimensioned and shaped to conduct or supply coolant to the cylinder head. The inlet channel 136 thus acts as a distributor component or collector for the coolant to be directed to the cylinder head and is integrated into the cylinder block. By integrating the inlet channel 136 into the cylinder block 76, 100, difficulties with outflow and manufacturability as well as costs can be reduced, and the control of the coolant flow to the cylinder head can be improved.

[0026] In the illustration, the intake port 136 is positioned outside the head bolt posts 148 defined in the cylinder block and the cylinders 102. The head bolt posts 148 cooperate with head bolts to secure the cylinder head to the cylinder block 76, 100 and encapsulate the combustion chamber 24. The intake port 136 is positioned in the illustration to provide a seal between the cylinders and to allow packaging of the intake port 136 using the cylinder head gasket between the top surfaces of the cylinder block and the cylinder head.

[0027] The intake passage 134 is fluidly connected to a fluid jacket 150. The fluid jacket 150 is formed within the cylinder block 76, 100 to surround the plurality of cylinders 102 and to conduct coolant and remove heat from the engine during operation. The fluid jacket 150 circumferentially surrounds the cylinders 102 and may generally follow the outer periphery of the cylinder liners of the cylinders 102, as shown. The fluid jacket 150 extends from the deck surface 118 into the cylinder block 76, 100. The fluid jacket 150 may include various cooling features, such as bore bridge cooling passages and the like, to enhance heat transfer and manage cylinder liner temperature.

[0028] With reference to Fig. 3, the intake passage 134 is shown in a sectional view of the cylinder block 76, 100. The intake passage 134 extends along and is located adjacent to the end wall 110 of the cylinder block 76, 100. The intake passage may be perpendicular to the longitudinal axis 104 or at a non-parallel angle.

[0029] In one example, the inlet passage 134 is defined as a continuous passage in the cylinder block 76, 100 such that it extends through both the inlet and outlet sides 114, 116 of the cylinder block 76, 100. The inlet passage 134 includes an inlet 160 configured to receive power from a pump in the cooling system. In one example, the pump may be directly connected to the cylinder block 76, 100 at a mounting surface adjacent to the inlet 160; in other examples, the pump may be remote from the cylinder block 76, 100 and connected via a pipe connection.

[0030] The inlet passage 134 may have a second inlet 162 or an opening on the outlet side 116. The inlet passage is connected to the supply channel 136 adjacent to this inlet 162. The inlet passage 134 has an intermediate region 164 positioned between the inlets 160, 162. The intermediate region 164 includes an opening 166 for directing a portion of the coolant in the passage 134 into the fluid jacket 150. The opening may include a ramp 168 or other feature for introducing a directional component into the flow to cause at least a portion of the coolant in Fig. 3 flows upwards and into the jacket 150. The fluid jacket 150 may be fluidly connected to the inlet passage 134 upstream of the inlet channel 136.

[0031] It is noted that in one example, all of the coolant from the pump may enter the inlet passage 134, with a portion of the coolant being directed to the jacket 150 and another portion of the remaining coolant being directed to the supply passage 136. It is noted that in the example shown, the supply passage 136 acts as a distribution component or collector for coolant to the cylinder head, such that all of the coolant for the head cooling circuit is provided through the block cooling circuit inlet passage 134 and the supply passage 136.

[0032] The cylinder block 76, 100 may include a cover 170 or a cover plate 170 for encapsulating and covering the open end 162 of the inlet passage 134. The cover 170 may be configured to connect to the outlet side 116 of the cylinder block and to encapsulate the connection between the inlet passage 134 and the inlet channel 136. The cover 170 may have a concave surface 172, as shown in Fig. 2 in dashed lines, to assist in directing flow, redirecting the coolant flow from the inlet passage 134 to the supply passage 136, and reducing the pressure drop caused by the redirection. In other embodiments, the passage 134 may not extend as a continuous passage within the cylinder block.

[0033] Fig. 4 shows a sectional view of the cylinder block 76, 100 and a cylinder head 80, 200 for the engine. The cylinder head 80, 200 can be used as a cylinder head 80, 200 of the Fig. 1. Coolant flows from the intake passage 134 and into the supply channel 136 in a connecting region 180. In one example, the connecting region 180 may include a 90-degree turn so that the coolant changes from a cross-flow direction to a longitudinal flow direction within the cylinder block 76, 100. The intake passage 134 is fluidly connected to the supply channel 136 adjacent the first cylinder 144 and the end 110 of the cylinder block 76, 100.

[0034] The intake passage 136 includes a floor 138 spaced from the top surface 118. The floor 138 may be sloped or otherwise shaped such that a distance between the floor 138 and the top surface 118 of the cylinder block decreases along the length of the intake passage and decreases downstream and away from the intake passage 134. The floor 138 may have portions that are continuously sloped, as shown, or that are continuously sloped for the length of the intake passage 136. The depth of the intake passage 136 at the first end 110 is greater than the downstream depth in the intake passage 136 at the second end 112 of the cylinder block. The decreasing depth of the supply passage 136 along the length of the supply passage in a downstream direction acts to control the coolant pressure along the length of the passage such that coolant is delivered to each cylinder in the cylinder head at substantially the same pressure and / or flow rate.

[0035] The bottom 138 of the intake passage 136 may include a protrusion 182 extending outward from the bottom 138 or upward and toward the deck surface 118. The intake passage 136 is shown as including a single protrusion 182, however, any number of protrusions and various protrusion locations are contemplated. The protrusion 182 may be located adjacent to the intake port 134 and the end 110 of the cylinder block. Due to the depth of the intake passage 136 at this end 110 and the associated greater distance from the deck surface 118, the protrusion is used to impart a vertical component to the coolant flow and direct coolant upward to the region of the cylinder head 80, 200 associated with the end cylinder 144 at this end 110.The projection 182 thus acts to redirect a portion of the coolant flow to provide a more even coolant distribution within the inlet passage 136 and along the deck surface 118 to the cylinder head 80, 200. The projection 182 may include various surface features, such as a concave upstream side 184, to better direct or control the coolant flow.

[0036] A cylinder head gasket 190 is positioned between the cylinder block 76, 100 and the cylinder head 80, 200. The cylinder head gasket 190 defines a series of passages 120, as shown in Fig. 1, positioned between and fluidly connecting the intake passage 136 of the cylinder block 76, 100 and one or more inlets 202 of the cylinder head 80, 200. The passages 120 are aligned with the inlets 202 and the intake passage 136. The cylinder head gasket 190 may be formed as a multi-layer steel cylinder head gasket with a vulcanized rubber bead to keep the coolant system sealed and separated from the oil drain passages, etc.

[0037] The cylinder head 80, 200 may include one or more inlets 202 configured to receive coolant flow from the intake passage 136 and into the cooling circuit 204 of the cylinder head 80, 200. The inlets 202 intersect the head deck surface 206. The cooling circuit 204 may be the circuit 86 of Fig. 1. The cylinder head 80, 200 may have a single cooling circuit or may have multiple cooling circuits, such as an upper and a lower cooling circuit. In the example shown, the head cooling circuit 204 has an associated inlet 202 for each cylinder 102 in the cylinder head 80, 200 and the engine. In other examples, more than one inlet 202 may be provided per cylinder 102.

[0038] The passages 120 in the cylinder head gasket 190 may be the same size or a substantially similar size and shape. In other examples, the shape and positioning of the passages 120 may vary to control the direction and / or rate of coolant flow through the passages 120, as shown. The passages 120 may also have different sizes or cross-sections to allocate the coolant flow through each passage 120 and to the associated cylinder in the cylinder head 80, 200.

[0039] In the example shown, the passages 120 in the seal 190 are spaced along the length of the intake passage 136. Each cylinder 102 in the engine may have one or more passages 120 associated with it. In the example shown, there is one passage 120 for each cylinder 102 for directing and distributing the coolant flow into the cylinder head 80, 200 for that cylinder. The cross-section of each passage 120 may increase downstream in the intake passage 136 or may decrease from right to left in Fig. 4 to supply a substantially equal amount of coolant to each cylinder. In other examples, the center passages 120 may be sized to have a larger cross-section than the outer passages associated with end cylinders, as the center cylinders may require additional cooling to operate at a similar temperature to the end cylinders.

[0040] Fig.5 illustrates another cross-sectional view of the engine. Coolant enters the cylinder head 80, 200 through the inlets 202 and flows into the head cooling circuit 204. The inlets 202 are located along one side of the engine, such as the exhaust side 116. The coolant in the head cooling circuit 204 flows generally transversely across the cylinder head 80, 200, e.g., from the exhaust side 116 to the intake side 114, or substantially perpendicular to the longitudinal axis 104 or at an angle thereto. At least a portion of the coolant in the cylinder head 80, 200 then flows downward from the head cooling circuit 204 through at least one outlet 208 defined in the cylinder head deck surface 206, through the passage 120 on the intake side 114, and to a return channel 192 in the cylinder block 76, 100. The cylinder head 80, 200 may have one or more outlets 208 per cylinder 102.

[0041] The return passage 192 forms part of the cooling system 130 and the cooling circuit 132 in the cylinder block 76, 100. The return passage 192 intersects the block deck 118 and is positioned between the intake sidewall 114 of the cylinder block and the plurality of cylinders 102. The return passage 192 may be generally opposite the continuous intake passage 136. The cooling system may include one or more return passages 192. In the example shown, there are two return passages 192 based on the central placement of an oil drain passage 194.

[0042] The coolant in the fluid jacket 150 and the coolant in the return channel 192 are then combined and flow through the cooling system 130 to the pump for recirculation.

[0043] The engine is thus cooled by supplying coolant from a pump 74 to an inlet passage 134 of a cooling system 130 formed in a cylinder block 76, 100. A first portion of the coolant in the inlet passage 134 is diverted to a fluid jacket 150 surrounding a plurality of cylinders 102 in the cylinder block 76, 100. A second portion of the coolant, or the remaining coolant in the inlet passage 134, is supplied to an open supply channel 136 formed in the cylinder block 76, 100. The inlet channel 136 intersects a block deck surface 118 and has a first end 142 fluidly connected to the inlet passage 134 adjacent a first end 110 of the cylinder block 76, 100, and a second end 146 adjacent a second opposite end 112 of the cylinder block 76, 100.The second portion of the coolant is distributed through a series of passages 120 in a cylinder head gasket 190 and to at least one inlet 202 in a cover surface 206 of the cylinder head 80, 200.

[0044] The second portion of the coolant flows from the inlets 202 across the plurality of cylinders 102 in the cylinder head 80, 200 to the outlets 208. The second portion of the coolant thus forms a parallel flow circuit, with the first portion of the coolant being located in the fluid jacket 150 of the cylinder block.

[0045] The second portion of the coolant in the cylinder head 80, 200 is directed and flows from the outlets 208 in the cylinder head 80, 200 to one or more return passages 192 formed in the cylinder block 76, 100. The return passages 192 intersect the block deck 118 and are generally opposite the supply passage 136. The first and second portions of the coolant are then recombined or mixed, completing the parallel flow circuit, and then fed to the pump for recirculation.

[0046] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms of the disclosure. Instead, the terms used in the description are for the purpose of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Furthermore, the features of the various implementation embodiments may be combined to form further embodiments of the disclosure. List of reference symbols 20 combustion engine 22 cylinders 24 combustion chamber 32 cylinder walls 34 pistons 36 Crankshaft 38 intake manifold 40 exhaust manifold 42 Inlet valve 44 Exhaust valve 46 Fuel injection valve 48 Spark plug 70 Cooling system 74 Pump 76 cylinder block 78 cylinder head gasket 80 cylinder head 82 coolers 84 First cooling circuit 86 Second cooling circuit 100 engine block 102 cylinders 104 Longitudinal axis 110 First end wall 112 Second end wall 114 First side wall 116 Second side wall 118 deck area 120 passages and slots 130 Cooling system 132 Cooling circuit 134 Inlet passage 136 inlet channel 138 floor 140 side wall 142 First End 144 end cylinders 146 Second End 148 head screw columns 150 fluid jacket 160 entrance 162 Second Inlet 164 Intermediate area 166 Opening 168 Ramp 170 Lid / cover plate 172 Concave surface 180 connection area 182 lead 184 Concave upstream side 190 cylinder head gasket 192 Return channel 194 Oil drain channel 200 cylinder head 202 inlets 204 Cooling circuit 206 deck area 208 outlets

Claims

[1] Engine comprising: a cylinder block (76) having a block cover surface (118), an inlet side wall (114), an outlet side wall (116) and a first (110) and a second end wall (112) which are opposite one another, wherein the cylinder block (76) defines a plurality of cylinders (22) which are arranged in series, wherein a first end cylinder (144) is located adjacent to the first end wall (110) and a second end cylinder (144) is located adjacent to the second end wall (112), wherein the cylinder block (76) defines a block cooling circuit (132) which has an inlet passage (134) which extends along the first end wall (110) and is fluidly connected to an inlet channel (136), wherein the inlet channel (136) intersects the block deck surface and has a continuous periphery extending longitudinally from a first end (142) adjacent the first end wall (110) and a second end (146) adjacent the second end wall (112), the inlet channel (136) being positioned between the exhaust side wall and the plurality of cylinders (22); and a cylinder head (80, 200) having a head deck surface (206) and defining a head cooling circuit (204), wherein at least one inlet (202) intersects the head deck surface (206) and is aligned with the inlet channel (136) for receiving coolant therefrom, wherein the inlet passage (134) of the cylinder block (76) extends from an inlet side (114) to the outlet side (116) through the cylinder block (76), wherein the intake passage (134) has an inlet (160) on the intake side (114) of the engine; and the cylinder block (76) has a cover (170) configured to connect to the exhaust side (116) of the engine and to encapsulate the connection between the inlet passage (134) and the inlet channel (136); characterized by that the block cooling circuit (132) defines a return channel (192) which intersects the block deck surface (118) and is positioned between the inlet side wall (114) and the plurality of cylinders (22), wherein the return channel (192) is generally opposite the continuous supply channel (136); and wherein the coolant circuit (130) defines at least one outlet (208) intersecting the head deck surface (206) and aligned with the return channel (192) for receiving coolant therefrom. [2] The engine of claim 1, further comprising a cylinder head gasket (190) disposed between the block deck surface (118) and the head deck surface (206), the cylinder head gasket (190) defining a series of passages (120) positioned between and fluidly connecting the supply passage (136) and the at least one inlet (202). [3] The engine of claim 2, wherein the series of passages (120) of the cylinder head gasket (190) are spaced along the length of the intake passage (136), each passage (120) being associated with a respective cylinder (22) of the plurality of cylinders (22), and a cross-section of each passage (120) increasing downstream of the intake passage (136). [4] The engine of claim 1, wherein the block cooling circuit (132) includes a fluid jacket (150) surrounding the plurality of cylinders (22) and fluidly connected to the intake passage (134) upstream of the intake channel (136). [5] The engine of claim 4, wherein the inlet passage (134) of the block cooling circuit (132) directs a portion of the coolant in the inlet passage (134) to the fluid jacket (150) and a remaining portion of the coolant in the inlet passage (134) to the supply channel (136); and wherein all of the coolant in the head cooling circuit (204) is supplied from the inlet passage (134) of the block cooling circuit (132). [6] The engine of claim 1, wherein a distance between a bottom of the inlet passage (136) and the block deck surface (118) decreases in a downstream direction along a length of the inlet passage (136), whereby coolant is supplied to each cylinder (22) in the cylinder head (80, 200) at substantially the same pressure. [7] The engine of claim 1, wherein the cover (170) includes a concave surface (172) configured to form a wall of the cooling circuit between the inlet passage (134) and the supply channel (136) and to direct flow from the inlet passage (134) to the supply channel (136). [8] Engine comprising: a cylinder block (76) defining a cooling circuit (132) having an inlet passage (134) located adjacent a first end (142) of the cylinder block (76) and fluidly connected to (i) a fluid jacket (150) circumferentially surrounding a plurality of cylinders (22) and (ii) a continuous open supply passage (136) positioned between a sidewall of the cylinder block (76) and the jacket, the supply passage (136) intersecting a block deck surface (118) and extending along each cylinder (22) of the plurality of cylinders (22), the supply passage (136) being configured to conduct coolant to a cylinder head (80, 200); characterized by that the cooling circuit (132) of the cylinder block (76) defines a return channel (192) which intersects the block cover surface (118) and positioned between another side wall of the cylinder block (76) and the plurality of cylinders (22), the return passage (192) being generally opposite the continuous supply passage (136), the return passage (192) being configured to receive coolant from the cylinder head (80, 200). [9] The engine of claim 8, wherein the inlet channel (136) has a bottom (138) spaced from the block deck surface (118) and a continuous sidewall (140) extending from the bottom to the deck surface. [10] The engine of claim 9, wherein a distance between the bottom (138) of the intake passage (136) and the block deck surface (118) decreases along a length of the intake passage (136) and away from the intake passage (134). [11] The engine of claim 9, wherein the plurality of cylinders (22) extend along a longitudinal axis (104) of the cylinder block (76), with a first end cylinder (144) located adjacent the first end of the cylinder block (76) and a second end cylinder (144) located adjacent a second end (146) of the cylinder block (76); and wherein the continuous open intake passage (136) is substantially parallel to the longitudinal axis and extends from the first end cylinder (144) to the second cylinder (144). [12] The engine of claim 11, wherein the intake passage (134) is fluidly connected to the inlet channel (136) adjacent the first end cylinder (144). [13] The engine of claim 12, wherein the bottom of the inlet channel (136) includes a protrusion (182) extending toward the block deck surface (118) and located adjacent the inlet passage (134), the protrusion (182) configured to redirect coolant to the first end cylinder (144). [14] The engine of claim 13, wherein the projection (182) has an upstream side, the upstream side being concave (184). [15] The engine of claim 8, wherein the cooling circuit (132) of the cylinder block (76) includes a fluid jacket (150) surrounding the plurality of cylinders (22), the fluid jacket (150) being fluidly connected to the intake passage (134) upstream of the intake channel (136). [16] The engine of claim 8, wherein the cylinder block (76) defines a series of head bolt columns (148) along the intake sidewall (114), the intake passage (136) being positioned between the series of head bolt columns (148) and the intake sidewall (114). [17] A method of cooling an engine, comprising: Providing coolant from a pump (74) to an inlet passage (134) of a cooling system (130) formed in a cylinder block (76), the cooling system (130) having an inlet passage (134) fluidly connected (i) to a fluid jacket (150) circumferentially surrounding a plurality of cylinders (22) and (ii) to an open inlet channel (136) intersecting a block deck surface (118) and having a first end (142) fluidly connected to the inlet passage (134) adjacent a first end (110) of the cylinder block (76) and a second end (146) adjacent a second opposite end (112) of the cylinder block (76), wherein the inlet channel (136) is arranged between the fluid jacket (150) and a first end side (110) of the cylinder block (76); Diverting a first portion of the coolant in the inlet passage (134) to a fluid jacket (150); Directing a second portion of the coolant in the inlet passage (134) to the open inlet channel (136); Distributing the second portion of coolant from the inlet channel (136) through a series of passages (120) in a cylinder head gasket (190) and to at least one inlet (162) in a cylinder head cover surface (206); Flowing the second portion of the coolant from the at least one inlet (162) in the cylinder head (80, 200) across the plurality of cylinders (22) in the cylinder head to at least one outlet (208) in the cylinder head deck surface (206), the second portion of the coolant being in a parallel flow circuit (86), the first portion of the coolant being in the fluid jacket (150) of the cylinder block (76); Directing the second portion of the coolant from the at least one outlet (208) in the cylinder head (80, 200) to a return passage (192) formed in the cylinder block (76), the return passage (192) intersecting the block deck surface (118) and being generally opposite the inlet passage (136), the return passage (192) being disposed between the fluid jacket (150) and a second side of the cylinder block (76); and Mixing the first and second parts of the coolant and feeding them to the pump (74), characterized by that the cooling circuit (132) of the cylinder block (76) defines a return channel (192) which intersects the block cover surface (118) and positioned between another side wall of the cylinder block (76) and the plurality of cylinders (22), the return passage (192) being generally opposite the continuous supply passage (136), the return passage (192) being configured to receive coolant from the cylinder head (80, 200).

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