Patent Abstract:
An engine includes a cylinder block having first and second passages intersecting a block face on opposed sides of a bore bridge defining a bore bridge cooling passage. A cylinder head has third and fourth passages intersecting a head face. The first and fourth passages are opposed from one another. A gasket is placed between the block and the head. The gasket adapted to fluidly connect the first and fourth passages via the bore bridge cooling passage, and cover the second passage.

Full Description:
TECHNICAL FIELD 
     Various embodiments relate to cooling passages for a bore bridge between two cylinders in an internal combustion engine. 
     BACKGROUND 
     In a water-cooled engine, sufficient cooling may need to be provided to the bore bridge between adjacent engine cylinders. The bore bridge on the cylinder block and/or the cylinder head is a stressed area with little packaging space. In small, high output engines, due to packaging, the thermal and mechanical stresses may be increased. Higher bore bridge temperatures typically cause bore bridge materials to weaken and may reduce fatigue strength. Thermally weakened structure and thermal expansion of this zone may cause bore distortion that can be problematic to overall engine functionality such as, for example, piston scuffing, sealing functionality and durability of the piston-ring pack. Additionally, high temperatures at the bore bridge area also limit the reliability of the gasket in this zone, which in turn may cause combustion gas and coolant leaks, and/or reduced engine power output and overheating. 
     SUMMARY 
     In an embodiment, an internal combustion engine is provided with a cylinder block defining a block deck face, first and second cylinders, and a block cooling jacket. The first and second cylinders are adjacent to one another and separated by a block bore bridge. A cylinder head has a head deck face defining first and second chambers, and a head cooling jacket. The first and second chambers are adjacent to one another and separated by a head bore bridge. The first chamber and the first cylinder form a first combustion chamber, and the second chamber and the second cylinder form a second combustion chamber. A head gasket is positioned between the cylinder block and the cylinder head. The head gasket has a block side and a head side. The block cooling jacket has a first passage and a second passage intersecting the block deck face on either side of the block bore bridge. The first passage is on a first side of a longitudinal axis of the cylinder block. The head cooling jacket has a third passage and a fourth passage intersecting the head deck face on either side of the head bore bridge. The third passage is on the first side of the longitudinal axis of the cylinder block. The block bore bridge defines a bridge cooling passage extending from the first passage adjacent to the block deck face to the block deck face adjacent to the second passage. The head gasket is adapted to fluidly connect the first and fourth passages such that coolant flows from the first passage, through the bridge cooling passage, and to the fourth passage to cool the associated bore bridge. 
     In another embodiment, an engine is provided with a cylinder block having first and second passages intersecting a block face on opposed sides of a bore bridge defining a v-shaped passage. A cylinder head has third and fourth passages intersecting a head face, with the first and fourth passages being opposed. A gasket is placed between the block and the head. The gasket is adapted to fluidly connect the first and fourth passages via the v-shaped passage, and cover the second passage. 
     In yet another embodiment, a head gasket for an engine having a cooling jacket is provided. The gasket has a generally planar gasket body with a first side for cooperation with a cylinder head deck face, and a second side for cooperation with a cylinder block deck face. The gasket has a first aperture extending through the gasket body and adjacent to a cylinder block bore bridge. The first aperture fluidly connects a first cooling passage in a cylinder block and a second cooling passage in a cylinder head, with the first and second cooling passages being aligned. The gasket has a second aperture extending through the gasket body and adjacent to the cylinder block bore bridge. The second aperture fluidly connects a bridge cooling passage in the cylinder block bore bridge receiving fluid from the first passage and a third cooling passage in the cylinder head. The first and second apertures are spaced apart transversely on the gasket. The gasket body is adapted to cover a fourth passage in the cylinder block, with the fourth passage adjacent to the v-shaped passage. 
     Various embodiments of the present disclosure have associated, non-limiting advantages. For example, by providing a v-shaped passage or another passage across the bore bridge to provide coolant flow from a block cooling jacket to a head cooling jacket on an opposed side of a bore bridge, the bore bridge temperature, cylinder temperature, and relative cylinder vertical displacement may be reduced. A gasket fluidly connects the block cooling jacket and the head cooling jacket on a first side of the bore bridge. The bore bridge cooling passage is fluidly connected to the block jacket on the first side of the bridge and spaced apart from and fluidly disconnected from the block cooling jacket on the second, opposed side of the bore bridge. The gasket fluidly connects the bore bridge passage to the head cooling jacket on the second side of the bore bridge. The gasket covers the block cooling jacket on the second side of the bore bridge to prevent coolant flow from the block jacket to the head jacket on the second side of the bore bridge. The bore bridge cooling passage and head gasket provide for an increased pressure drop across the bore bridge, providing for increased coolant velocity and increased heat transfer of the bore bridge. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a schematic of an engine configured to implement the disclosed embodiments; 
         FIG. 2  illustrates a schematic of cooling paths for a cooling jacket of a conventional engine; 
         FIG. 3  illustrates a schematic of cooling paths for a cooling jacket of the engine of  FIG. 1  according to an embodiment; 
         FIG. 4  illustrates a perspective view of a cylinder block according to an embodiment; 
         FIG. 5  illustrates a graph of surface temperature around a cylinder bore and compares the cooling paths of the present disclosure to conventional engines; 
         FIG. 6  illustrates a graph of surface temperature as a function of bore length of a cylinder and compares the cooling paths of the present disclosure to conventional engines; and 
         FIG. 7  illustrates a graph of the vertical displacement of the bore edge relative to the in-cylinder lowest value around a cylinder bore and compares the cooling paths of the present disclosure to conventional engines. 
     
    
    
     DETAILED DESCRIPTION 
     As required, detailed embodiments of the present disclosure are disclosed herein; however, it is to 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. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure. 
       FIG. 1  illustrates a schematic of an internal combustion engine  20 . The engine  20  has a plurality of cylinders  22 , and one cylinder is illustrated. The engine  20  has a combustion chamber  24  associated with each cylinder  22 . The cylinder  22  is formed by cylinder walls  32  and 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  may be operated in various ways as is known in the art to control the engine operation. 
     A fuel injector  46  delivers fuel from a fuel system directly into the combustion chamber  24  such that the engine is a direct injection engine. A low pressure or high pressure fuel injection system may be used with the engine  20 , or a port injection system may be used in other examples. An ignition system includes a spark plug  48  that is controlled to provide energy in the form of a spark to ignite a fuel air mixture in the combustion chamber  24 . In other embodiments, other fuel delivery systems and ignition systems or techniques may be used, including compression ignition. 
     The engine  20  includes a controller and various sensors configured to provide signals to the controller for use in controlling the air and fuel delivery to the engine, the ignition timing, the power and torque output from the engine, and the like. Engine sensors may include, but are not limited to, an oxygen sensor in the exhaust manifold  40 , an engine coolant temperature, an accelerator pedal position sensor, an engine manifold pressure (MAP sensor, an engine position sensor for crankshaft position, an air mass sensor in the intake manifold  38 , a throttle position sensor, and the like. 
     In some embodiments, the engine  20  is used as the sole prime mover 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 prime mover, such as an electric machine, is available to provide additional power to propel the vehicle. 
     Each cylinder  22  may operate under 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 with 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 introduce air from the intake manifold to the combustion chamber. The piston  34  position at the top of the cylinder  22  is generally known as top dead center (TDC). The piston  34  position at the bottom of the cylinder is generally known as bottom dead center (BDC). 
     During the compression stroke, the intake and exhaust valves  42 ,  44  are closed. The piston  34  moves from the bottom towards the top of the cylinder  22  to compress the air within the combustion chamber  24 . 
     Fuel is then introduced into the combustion chamber  24  and ignited. In the engine  20  shown, the fuel is injected into the chamber  24  and is then ignited using spark plug  48 . In other examples, the fuel may be ignited using compression ignition. 
     During the expansion stroke, the ignited fuel air mixture in the combustion chamber  24  expands, thereby 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 crankshaft  36  and provides for a mechanical torque output from the engine  20 . 
     During the exhaust stroke, the intake valve  42  remains closed, and the exhaust valve  44  opens. The piston  34  moves from the bottom of the cylinder to the top of the cylinder  22  to remove the exhaust gases and combustion products from the combustion chamber  24  by reducing the volume of the chamber  24 . The exhaust gases flow from the combustion cylinder  22  to the exhaust manifold  40  and to an after treatment system such as a catalytic converter. 
     The intake and exhaust valve  42 ,  44  positions and timing, as well as the fuel injection timing and ignition timing may be varied for the various engine strokes. 
     The engine  20  includes a cooling system  70  to remove heat from the engine  20 . The amount of heat removed from the engine  20  may be controlled by a cooling system controller or the engine controller. The cooling system  70  may be integrated into the engine  20  as a cooling jacket. The cooling system  70  has one or more cooling circuits  72  that may contain water or another coolant as the working fluid. In one example, the cooling circuit  72  has a first cooling jacket  84  in the cylinder block  76  and a second cooling jacket  86  in the cylinder head  80  with the jackets  84 ,  86  in fluid communication with each other. The block  76  and the head  80  may have additional cooling jackets. Coolant, such as water, in the cooling circuit  72  and jackets  84 ,  86  flows from an area of high pressure towards an area of lower pressure. 
     The cooling system  70  has one or more pumps  74  that provide fluid in the circuit  72  to cooling passages in the cylinder block  76 . The cooling system  70  may also include valves (not shown) to control to flow or pressure of coolant, or direct coolant within the system  70 . The cooling passages in the cylinder block  76  may be adjacent to one or more of the combustion chambers  24  and cylinders  22 , and the bore bridges formed between the cylinders  22 . Similarly, the cooling passages in the cylinder head  80  may be adjacent to one or more of the combustion chambers  24  and cylinders  22 , and the bore bridges formed between the combustion chambers  24 . The cylinder head  80  is connected to the cylinder block  76  to form the cylinders  22  and combustion chambers  24 . A head gasket  78  in interposed between the cylinder block  76  and the cylinder head  80  to seal the cylinders  22 . The gasket  78  may also have a slot, apertures, or the like to fluidly connect the jackets  84 ,  86 , and selectively connect passages between the jackets  84 ,  86 . Coolant flows from the cylinder head  80  and out of the engine  20  to a radiator  82  or other heat exchanger where heat is transferred from the coolant to the environment. 
       FIG. 2  illustrates a conventional cross drill design for a bore bridge of the engine block. In other conventional engines, the bore bridge may have no cooling passages.  FIG. 2  illustrates cooling paths across the bore bridge. The cylinder block  100  of the engine is connected to the cylinder head  102  using a head gasket  104  to form a combustion chamber in the engine. The deck face  103  of the cylinder block  100  and the deck face  101  of the cylinder head  102  are in contact with first and second opposed sides of the gasket  104 . The cylinder head  102  has bore bridges  106  between adjacent chambers. The block  100  has bore bridges  126  between adjacent cylinders. 
     Coolant flows from a block cooling jacket  130  to a head cooling jacket  150 . The block jacket  130  has a passage  132  on the intake side of the engine and a passage  134  on the exhaust side of the engine. The head jacket  150  has a passage  152  on the intake side of the engine and a passage  154  on the exhaust side of the engine. The bore bridge  126  defines a conventional y-shaped cross drill passage  160  for cooling. The flow of coolant is illustrated in Figure by arrows. In an example of  FIG. 2 , a pressure drop across the bore bridge, or at the entrance to  160  from passage  132  and the exit of passage  160  to passage  134 , is approximately 500 Pascals. 
       FIGS. 3-4  illustrate an example of the present disclosure.  FIG. 3  illustrates a schematic of fluid flow across a bore bridge according an example of the present disclosure.  FIG. 4  illustrates the cylinder block. Reference numerals in  FIG. 2  may also be used with reference to  FIGS. 3-5  for similar features. 
     The cooling system of  FIG. 2  may be implemented on the engine illustrated in  FIG. 1 .  FIG. 2  illustrates cooling paths across the cylinder block bore bridge. The cylinder block  100  of the engine is connected to the cylinder head  102  using a head gasket  104  to form a combustion chamber in the engine. The deck face  103  of the cylinder block  100  and the deck face  101  of the cylinder head  102  are in contact with first and second opposed sides of the gasket  104 . 
     Between adjacent chambers in the cylinder head  102  are bore bridges  106 . Between adjacent cylinders  124  in the block  100  are bore bridges  126 . The chambers in the head  102  and the cylinders in the block  100  cooperate to form combustion chambers for the engine. The gasket  104  may include a bead on each side of the gasket and surrounding the chambers and cylinders to help seal the combustion chambers of the engine. 
     An embodiment of the engine block  100  is shown in  FIG. 4  illustrating the longitudinal axis L and the transverse axis T of the engine, as well as the intake side I and the exhaust side E. Referring back to  FIG. 3 , coolant flows from a block cooling jacket  130  to a head cooling jacket  150 . The block jacket  130  has a passage  132  on the intake side of the engine and a passage  134  on the exhaust side of the engine. Passages  132  and  134  intersect the block deck face  103 . The head jacket  150  has a passage  152  on the intake side of the engine and a passage  154  on the exhaust side of the engine. Passages  152 ,  154  intersect the head deck face  101 . The bore bridge  126  is a fluid barrier between passages  132 ,  134  and is adapted to prevent coolant from flowing directly from the passage  132  to the passage  134  and separate adjacent cylinders in the engine block  100 . 
     The bore bridge  126  defines a v-shaped cross drill passage  170  for cooling. The flow of coolant is generally illustrated in  FIG. 3  by arrows. In an example of  FIG. 3 , a pressure drop across the bore bridge, or at the entrance to  170  from passage  132  and the exit of passage  170  to passage  154 , is approximately 8000 Pascals for the same operating conditions as described above with respect to  FIG. 2 , thereby providing approximately sixteen times greater pressure drop. An increased pressure difference provides a higher flow velocity, and associated higher heat transfer rates, in the bore bridge  126 . 
     The v-shaped passage  170  has a first section of passage  172  and a second section of passage  174 . The passage  172  extends from the passage  132  adjacent to the block deck face  103  to an intermediate region  176  of the bore bridge  126 . The passage  174  extends from and connects with the passage  172  in the intermediate region  176  of the bore bridge  126 . The passage  174  intersects the block deck face  103  adjacent to and spaced apart from the passage  134 . 
     Passage  172  is nonparallel with and intersects the passage  174 . The passage  172  is oriented at an acute angle with the block deck face  103  as shown by angle a. The passage  174  is oriented at an acute angle with the block deck face  103  as shown by angle b. The angles a, b, may be the same as one another or may be different from one another. Similarly, the length and/or diameter of passages  172 ,  174  may be the same as one another or different than one another. The intermediate region  176  of the block bore bridge is spaced apart from the block deck face  103 . 
     An end or exit  178  of the v-shaped passage intersects the block face  103  and is spaced apart from the passage  134 . The exit  178  of the v-shaped passage may be aligned with the passage  154  of the head  102 , or alternatively, the gasket  104  may be slotted to provide a fluid connection between the exit  178  and the passage  154  as shown in  FIG. 3 . Another end, or the entrance  180  of the v-shaped passage intersects the cooling passage  152 , and may be adjacent to the deck face  103 . 
     Coolant in the block cooling jacket  130  flows from a passage  132  on the intake side, across bore bridge  126 , and to a passage  154  in the cooling jacket  150  on the exhaust side of the cylinder head  102 . The passage  154  is at a lower pressure than passage  132 . Coolant in passage  132  also flows to passage  152  in the jacket  150 . The gasket  104  isolates the passage  134  adjacent to the bore bridge, forcing passage  154  to receive coolant from the passage  170 , thereby increasing flow across the bore bridge  126 . 
     The head gasket  104  assists in providing the cooling paths as shown in  FIG. 2 . The gasket  104  has a generally planar gasket body that defines various apertures corresponding to bolt holes or other components of the engine. The gasket  104  also has slots or apertures to form cooling passages to fluidly connect the jackets  130 ,  150 . In one example, the gasket  104  is constructed from multiple layers, and each layer may be made from steel or another suitable material. One or more center layers  182  may be used as a spacer, and it may assist in determining the gasket thickness as well as provide a separating layer. The gasket has at least one upper layer  184  on the head side of the gasket  104 . The gasket  104  also has at least one lower layer  186  on the block side of the gasket. The upper layer  184  cooperates with the cylinder head deck face  101 , the lower layer  186  cooperates with the cylinder block deck face  103 , and the intermediate layer  182  is positioned between the upper and lower layers. 
     The gasket  104  has a first aperture or slot  188  positioned between passage  132  and passage  152 . The aperture  188  may be the same dimensions as the passages  132 ,  152 , or may be smaller in size to restrict flow. The gasket has a second aperture or slot  190  positioned between the exit  178  of the v-shaped passage  170  and the passage  154 . The slots  188 ,  190  may be formed by stamping the layers of the gasket, or by another process as is known in the art. Each slot is positioned between adjacent beads of the gasket. The slots or apertures  188 ,  190  may be formed by selectively removing gasket material from one or more layers to form a coolant path from the block to the head. Slots may be provided in each layer of the gasket that cooperate to form the coolant path across the gasket, and slots in different layers may be the same length, different lengths, and may be aligned or offset to provide the desired coolant flow pattern. The apertures  188 ,  190  are spaced apart transversely along the T axis on the gasket. 
     At least one layer of the gasket  104 , such as layer  186 , covers the passage  134  at the deck face to prevent flow from the passage  134  to the passage  154  adjacent to the bore bridge  126 . Therefore, in the region of the bore bridge  126 , passages  132 ,  152 ,  170 , and  154  are in direct fluid communication, and passage  134  is blocked or fluidly disconnected. 
     The perimeter of the apertures  188 ,  190  may be generally triangular, circular, or another shape to correspond with perimeters of associated passages. In some examples, the cross sectional area of the apertures  188 ,  190  corresponds with the cross sectional area of at least one or the associated passages taken along the deck face to prevent flow restrictions. In other examples, the cross sectional area of the apertures  188 ,  190  is less than the cross sectional area of at least one or the associated passages taken along the deck face to provide a flow restriction to control flow. The apertures  188 ,  190  may also have a diverging cross sectional area or a converging cross sectional area across the gasket  104  to control flow, for example, to control a fluid streamline. 
     Although the coolant is described as flowing from the intake side of the engine to the exhaust side, in other embodiments, the coolant may flow in the opposite direction, i.e. from the exhaust side to the intake side, and the v-shaped passage  170  may be reversed. 
     Coolant flow through the engine is generally shown by the arrows in  FIG. 3 . The gasket  104  may provide a coolant flow path from the block  100  to the head  102  through the bore bridge  126 . The gasket  104  may provide a barrier at passage  134 , thereby causing the coolant to flow transversely from an intake side to an exhaust side of the engine across the bore bridge. 
     Coolant in the cylinder head passages in the block deck face may travel along a longitudinal axis or longitudinal direction L of the engine such that coolant is provided to the cylinders in a sequential manner. 
       FIG. 4  illustrates a partial top perspective view of a cylinder block  100  employing an embodiment of the present disclosure. The cylinder block  100  may be cast out of a suitable material such as aluminum. The cylinder block  100  is a component in an in-line four cylinder engine, although other engine configurations may also be used with the present disclosure. The cylinder block  100  has a deck face  103  or top face that forms cylinders  124 . The deck face  103  may be formed to provide a semi-open deck design as illustrated. Each cylinder  124  cooperates with a corresponding chamber in the head  102  to form the combustion chamber. Each cylinder  124  has an exhaust side E that corresponds to the side of the head with the exhaust ports, and an intake side I that corresponds to the side of the head with the intake ports. Various passages are also provided on the deck face  103  and within the cylinder block  100  that form a cooling jacket  130  for the cylinder block and engine. The cooling jacket  130  may cooperate with corresponding ports associated with a head cooling jacket to form an overall cooling jacket for the engine. Coolant in the cylinder block passages in the block deck face may travel along a longitudinal axis or longitudinal direction L as shown by the arrow in  FIG. 4  of the engine such that coolant is provided to the cylinders in a sequential manner. 
     A bore bridge  126  is formed between a pair of cylinders  124 . The bore bridge  126  may require cooling with engine operation as the temperature of the bridge  126  may increase due to conduction heating from hot exhaust gases in the combustion chamber. The exit  178  of a v-shaped passage  170  is illustrated and is adjacent to and spaced apart from the passage  134 . The exit  178  intersects the deck face  103 . 
       FIGS. 5-7  illustrate modeling results comparing an engine without a bore bridge cooing passage, an engine with a bore bridge cooling passage according to  FIG. 2 , and a bore bridge cooling passage  170  according to  FIG. 3  and the present disclosure. The results were calculated for the number three cylinder in the engine, which encounters the greatest heating and/or displacement of the engine bore bridges. Generally, the Figures show that the passage  170  provides a high pressure drop across the passage  170  which increases the coolant flow and heat transfer significantly. The passage  170  reduces bore bridge temperature, reduces the temperature and displacement gradient around the bore edge, and reduces bore wall temperature along the bore length. In one example, a temperature of the bore bridge and a maximum block temperature using a passage  170  are reduced by approximately thirty degrees Celsius compared to an engine with no bore bridge cooling passage. For comparison, a temperature of the bore bridge and a maximum block temperature using a passage  160  are reduced by approximately ten degrees Celsius compared to an engine with no bore bridge cooling passage. 
       FIG. 5  illustrates a surface temperature around a cylinder bore adjacent to the deck face  103 . The surface temperature is plotted as a function of angle in degrees around the cylinder. The longitudinal axis of the engine, or the center of the bore bridges, is at 90 degrees and 270 degrees. The temperature of the cylinder bore with no bore bridge cooling passages is shown by line  200 , and the temperature peaks at the angular position associated with the bore bridges. The temperature of the cylinder bore with cooling passages  160  in the bore bridges as shown in  FIG. 2  is shown by line  202 , which provides some temperature relief compared to line  200 . The temperature of the cylinder bore with cooling passages  170  in the bore bridges as shown in  FIG. 3  according to the present disclosure are shown by line  204 , which provides significant temperature relief compared to lines  200  and  202 . 
       FIG. 6  illustrates a surface temperature of a cylinder bore as a function of bore length, with increasing bore depth away from the deck face. In  FIG. 6 , a distance of zero is associated with the deck face  103  of an engine block. The surface temperature was calculated for the cylinder bore at an angular position of 90 degrees as described with respect to  FIG. 5  along a bore bridge. The longitudinal axis of the engine, or the center of the bore bridge, is at 90 degrees. The temperature of the cylinder bore with no bore bridge cooling passages is shown by line  210 , and the temperature peaks at the deck face  103 . The temperature of the cylinder bore with cooling passages  160  in the bore bridges as shown in  FIG. 2  is shown by line  212 , which provides some temperature relief compared to line  210 . The dip at  214  may be attributed to the lower passage connecting to passage  134  in  FIG. 2 . The temperature of the cylinder bore with cooling passages  170  in the bore bridges as shown in  FIG. 3  according to the present disclosure are shown by line  216 , which provides improved temperature relief compared to lines  210  and  212  adjacent to the deck face  103 . 
       FIG. 7  illustrates a graph of the vertical displacement of the bore edge relative to the in-cylinder lowest value around a cylinder bore. The relative vertical displacement is determined by subtracting the minimum vertical displacement for the cylinder from the vertical displacement curve around the cylinder. The relative vertical displacement is plotted as a function of angle in degrees around the cylinder. The longitudinal axis of the engine, or the center of the bore bridges, is at 90 degrees and 270 degrees. The relative vertical displacement is greatest at the bore bridges due to the increased temperature of the bore bridges and associated thermal expansion. The relative vertical displacement of the cylinder bore with no bore bridge cooling passages is shown by line  220 . The relative vertical displacement of the cylinder bore with cooling passages  160  in the bore bridges as shown in  FIG. 2  is shown by line  222 , which provides some vertical displacement relief compared to line  220 . The vertical displacement of the cylinder bore with cooling passages  170  in the bore bridges as shown in  FIG. 3  according to the present disclosure are shown by line  224 , which provides improved vertical displacement relief compared to lines  220  and  222 . 
     Various embodiments of the present disclosure have associated, non-limiting advantages. For example, by providing a v-shaped passage or another passage across the bore bridge to provide coolant flow from a block cooling jacket to a head cooling jacket on an opposed side of a bore bridge, the bore bridge temperature, cylinder temperature, and relative cylinder vertical displacement may be reduced. A gasket fluidly connects the block cooling jacket and the head cooling jacket on a first side of the bore bridge. The bore bridge cooling passage is fluidly connected to the block jacket on the first side of the bridge and spaced apart from and fluidly disconnected from the block cooling jacket on the second, opposed side of the bore bridge. The gasket fluidly connects the bore bridge passage to the head cooling jacket on the second side of the bore bridge. The gasket covers the block cooling jacket on the second side of the bore bridge to prevent coolant flow from the block jacket to the head jacket on the second side of the bore bridge. The bore bridge cooling passage and head gasket provide for an increased pressure drop across the bore bridge, providing for increased coolant velocity and increased heat transfer of the bore bridge. 
     While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the present disclosure. Rather, the words used in the specification are words 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. Additionally, the features of various implementing embodiments may be combined to form further embodiments.

Technology Classification (CPC): 5