Head gasket having variable area coolant openings

An engine assembly is provided herein. The engine assembly includes a head gasket interposing a cylinder block and a cylinder head, the head gasket comprising a first layer in face sharing contact with a portion of a cylinder head attachment surface included in the cylinder block and having a first-layer coolant opening adjacent to two neighboring cylinders and a second layer having a second-layer coolant opening having a smaller cross-sectional area than the first-layer coolant opening.

Internal combustion engines may experience an increase in temperature during combustion operation. To mitigate thermal degradation to the engine, cooling systems have been developed to cool components in the engine, such as the cylinder block and the cylinder head.

U.S. Pat. No. 4,377,990 discloses a water-cooled internal combustion engine with a cylinder head water jacket in fluidic communication with a cylinder block water jacket. A head gasket is disposed between the cylinder head and the cylinder block. The head gasket includes water galleries enabling coolant to flow through the gasket and between passages in the cylinder head and the cylinder block.

However, the inventors have recognized several drawbacks with cooling approaches such as the example above. For example, the location, size, and geometry of the water galleries in the head gasket may not provide sufficiently controlled cooling to certain sections of the cylinder head and the cylinder block, creating a potential for temperature above a desired operating value during engine operation. For example, the bridges between cylinders may experience less cooling than other areas of the cylinder block and the cylinder head, such as the exhaust manifold. As a result, uneven cooling in the cylinder block and/or cylinder head may lead to warping, cracking, as well as other types of thermal degradation. Furthermore, over-temperature conditions in some areas in the cylinders may decrease combustion efficiency and increase emissions. Further still, over-temperature conditions at bore bridge locations may increase head gasket degradation and top piston ring wear.

As such, in one approach an engine assembly is provided. The engine assembly includes a head gasket interposing a cylinder block and a cylinder head, the head gasket comprising a first layer in face sharing contact with a portion of a cylinder head attachment surface included in the cylinder block and having a first-layer coolant opening adjacent to two neighboring cylinders and a second layer having a second-layer coolant opening having a smaller cross-sectional area than the first-layer coolant opening.

In this way, the first-layer coolant opening may be sized and positioned to provide desired cooling to selected areas of the engine without necessarily compromising the structural integrity of the cylinder head and/or cylinder block through the addition of extra passages (although extra passages may be added, if desired). As a result in one embodiment, desired cooling may be provided to the bore bridge, enabling the bore bridge temperature to be maintained within limits during engine operation. Increasing the cross-sectional area of the first-layer coolant opening increases the amount of coolant that may be flowed near the cylinder block and specifically the bore bridge, thereby increasing the cooling provided to the bore bridge, if desired. Additionally, increasing the cross-sectional area of the first-layer coolant opening generates increased turbulence in the coolant flowing through the opening during some operating conditions. Therefore, the amount of heat that may be transferred to the coolant is increased. Additionally, increasing the cross-sectional area of the first-layer opening enables the coolant to travel across a greater amount of the cylinder block. Consequently, the thermal variability in the cylinder head and/or cylinder block may be decreased, thereby decreasing the likelihood of warping or other thermal degradation of the cylinder block and/or cylinder head.

DETAILED DESCRIPTION

A layered head gasket having a column of openings with a variable cross-sectional area of the openings is described herein. Specifically, the cross-sectional area of the column decreases in a downstream direction through the head gasket and is positioned adjacent to a bore bridge in the engine assembly. An exterior block interfacing layer in the head gasket may include a block interfacing layer coolant opening which extends from a first cylinder sealing bead to a second cylinder sealing bead. Each of the cylinder sealing beads is included in the exterior block interfacing layer and encloses separate neighboring cylinders. In this way, increased coolant may flow next to the bore bridge in the cylinder block, thereby decreasing bore bridge temperatures, as well as decreasing thermal variability in the engine assembly. Moreover, the manufacturing cost of the engine assembly may be decreased when the cross-sectional area of the first-layer coolant opening is increased when compared to engine assemblies that may provide additional coolant passages in the cylinder block via tooling (e.g., drilling, saw cuts, etc.) at a late stage in the manufacturing process. However, additional coolant passages may be provided in the cylinder block, if desired.

FIG. 1shows a schematic depiction of an engine assembly100included in a vehicle150. The engine assembly100includes a cylinder head102and a cylinder block104. A head gasket106is positioned between the cylinder head102and the cylinder block104. Thus, the head gasket106interposes the cylinder head102and the cylinder block104. Therefore, the head gasket106is sandwiched between the cylinder head102and the cylinder block104. The head gasket106has additional features that are not depicted inFIG. 2. For example, the head gasket106may include coolant openings enabling coolant to pass through the head gasket106. These and other additional features are shown inFIGS. 3-9and described in greater detail herein.

The cylinder block104and the cylinder head102attach to form a first cylinder108, a second cylinder110, a third cylinder112, and a fourth cylinder114. The cylinders (108and114) may be referred to as peripheral cylinders. On the other hand, cylinders (110and112) may be referred to as interior cylinders. In the embodiment depicted inFIG. 2, the engine assembly100includes four cylinders. However, in other embodiments an alternate number of cylinders may be used. As shown, the cylinders (108,110,112, and114) are in an inline configuration. That is to say a straight line passes through the central axis of each cylinder. However, other cylinder layouts have been contemplated. Each cylinder may include at least one intake valve115and at least one exhaust valve117. Additionally, ignition devices, such as spark plugs, may be coupled to the cylinders to facilitate combustion. Furthermore, fuel injectors may be directly coupled to the cylinders. Additionally or alternatively, the engine may utilize compression ignition and/or fuel injectors may be positioned upstream of the cylinders. The cylinders may be coupled to a crankshaft, which may be coupled to a transmission.

The engine assembly100further includes a cooling system120. The cooling system may include a cylinder head water jacket122and a cylinder block water jacket124. The cylinder head water jacket122includes a plurality of coolant passages traversing the cylinder head102Likewise, the cylinder block water jacket124includes a plurality of coolant passages traversing the cylinder block104. At least some of the coolant passages in the cylinder head water jacket122may be in fluidic communication with coolant passages in the cylinder block water jacket124. The head gasket106may include coolant openings configured to accommodate the flow of coolant from the cylinder head water jacket122to the cylinder block water jacket124or vice-versa.

As shown, the cylinder head water jacket122includes at least one coolant outlet126. The coolant outlet126may be an outlet of at least one coolant passage. Additionally, the cylinder block water jacket124includes at least one coolant inlet128. The coolant inlet128may be the inlet of at least one coolant passage. However, in other examples, each of the cylinder head water jacket122and the cylinder block water jacket124may include a coolant inlet and a coolant outlet or the cylinder head water jacket122may include a coolant inlet and the cylinder block water jacket124may include a coolant outlet.

The cooling system120includes a pump130in fluidic communication with the coolant outlet126and the coolant inlet128. The pump130is configured to increase the head pressure in the coolant circuit. In this way, coolant may be circulated through the cylinder block water jacket124and the cylinder head water jacket122. Arrow132denotes the flow of coolant from the pump130to the coolant inlet128. In this way, coolant may flow through one or more coolant passages.

The cooling system120also includes a heat exchanger134(e.g., radiator). The heat exchanger134is in fluidic communication with the pump130and the coolant outlet126. The heat exchanger134is configured to remove heat from coolant in the cooling system120. Specifically, the heat exchanger134may be configured to transfer heat to the surrounding air. However in other examples, the heat exchanger may transfer heat to another fluid.

Arrow136denotes the flow of coolant from the heat exchanger134to the pump130. Additionally, arrow138denotes the flow of coolant from the coolant outlet126to the heat exchanger134. In this way, coolant may be circulated through the cooling system120via coolant passages.

Coolant may flow between the cylinder head water jacket122and the cylinder block water jacket124. Specifically, coolant may travel from a plurality of coolant passage outlets142in the cylinder block water jacket124to a plurality of coolant passage inlets140in the cylinder head water jacket124. Arrows146denote the flow of coolant from the cylinder block water jacket124to the cylinder head water jacket122through the head gasket106. Columns of openings for coolant flow may be included in the head gasket106to enable coolant to flow therethrough. The columns of coolant openings are discussed in greater detail herein with regard toFIGS. 3-9.

FIG. 2shows an exploded view of an example engine assembly100shown inFIG. 2. The cylinder head102and the cylinder block104in the engine assembly are shown. A first cylinder section250, a second cylinder section252, a third cylinder section254, and a fourth cylinder section256included in the cylinder block104are also shown inFIG. 3. It will be appreciated that the first cylinder section250is included in the first cylinder108shown inFIG. 1. Likewise, the second cylinder section252is included in the second cylinder110shown inFIG. 1, the third cylinder section254is included in the third cylinder112, and the fourth cylinder section256is included in the fourth cylinder114. Continuing withFIG. 2, each of the cylinder sections (250,252,254, and256) include walls258defining the boundary of each respective cylinder.

The cylinder head102includes a cylinder block attachment surface801, shown and further described inFIG. 8. Likewise, the cylinder block104includes a cylinder head attachment surface200. The cylinder head attachment surface200includes attachment bores202. The attachment bores202are positioned on an intake side204of the cylinder block104and an exhaust side206of the cylinder block104. In one example, the attachment bores202on the intake side204of the cylinder block104may be configured to receive dowels. The dowels are used to fix the relative position of the cylinder head102and the cylinder block104. Continuing with the example, the attachment bores on the exhaust side206may be configured to receive bolts. In this example, the attachment bores on the exhaust side206may be referred to as mounting holes. Specifically, the cylinder block104may include ten mounting holes. The mounting holes may be concentric to the attachment bores. However other configurations have been contemplated. For example, the attachment bores on the exhaust side206may be configured to receive dowels and the attachment bores on the intake side204may be configured to receive bolts or a portion of the attachment bores on both the intake side204and exhaust side206may be configured to receive dowels and another portion of the attachment bores on the intake side and the exhaust side may be configured to receive bolts. In another example, all of the attachment bores202may be bolt holes An axis208extending longitudinally down the cylinder block104may be the boundary dividing the cylinder block104as well as the engine assembly100into an intake side and an exhaust side. The axis208extends through the central axis of each cylinder. The engine assembly100also includes bore bridges. Bore bridges are areas on both the cylinder block attachment surface801, shown inFIG. 8, and the cylinder head attachment surface200that extend between attachment bores on opposing sides of the engine assembly100. Thus, the bore bridges extend between neighboring cylinders.

The cylinder block104may also include a front side210and a rear side212. The attachment bores202may be configured to receive dowels, bolts, or other suitable attachment apparatuses for coupling the cylinder head102to the cylinder block104or fixing the relative position of the cylinder head and the cylinder block. The attachment bores202are laterally positioned between the cylinders sections (250,252,254, and256). A lateral, longitudinal, and vertical axis are provided for reference.

The cylinder block104further includes a plurality of cylinder block coolant passage outlets. The cylinder block coolant passage outlets direct coolant into a column of coolant openings in the head gasket106. Coolant then flows from the column of coolant openings to coolant passages in the cylinder head water jacket122, shown inFIG. 1. In particular, a first set of cylinder block coolant passage outlets230is positioned on the exhaust side206of the cylinder block104. Specifically, the first set of cylinder block coolant passage outlets230includes an outlet positioned between the first and second cylinder sections (250and252), an outlet positioned between the second and third cylinder sections (252and254), and an outlet positioned between the third and fourth cylinder sections (254and256). A second set of cylinder block coolant passage outlets232is positioned in the intake side204of the cylinder block104. The first and second set of cylinder block coolant passage outlets (230and232) may be included in the plurality of coolant passage outlets142, shown inFIG. 1. Thus, the coolant passage outlets (230and232) may be included in the cylinder block water jacket124. The first and second set of coolant passage outlets may flow coolant into openings in the head gasket106.

The second set of cylinder block coolant passage outlets232includes an outlet positioned between the first and second cylinder sections (250and252), an outlet positioned between the second and third cylinder sections (252and254), and an outlet positioned between the third and fourth cylinder sections (254and256). It will be appreciated that the first set of cylinder block coolant passage outlets230is mirrored by the second set of cylinder block coolant passage outlets232about the axis208. Thus, the first set of coolant passage outlets230has a similar size and geometry to the second set of coolant passage outlets232. However, other inlet locations and configurations have been contemplated. The cylinder block104may include additional cylinder block coolant passage outlets234positioned around the periphery of the cylinder sections (250,252,254, and256).

The head gasket106interposes the cylinder head102and the cylinder block104. The head gasket106provides sealing to the cylinders (108,110,112, and114), shown inFIG. 1, to reduce the likelihood of coolant leaking into the cylinders. The head gasket106includes a plurality of layers. Specifically, the head gasket106includes an exterior block interfacing layer214, an interior layer216, and an exterior head interfacing layer218. The exterior block interfacing layer214may be in face sharing contact with the cylinder block104, when the engine assembly100is assembled. Likewise, the exterior head interfacing layer118may be in face sharing contact with the cylinder head102, when the engine assembly100is assembled.

The exterior block interfacing layer214may be referred to as a first layer, the interior layer216may be referred to as a second layer, and the exterior head interfacing layer218may be referred to as a third layer. Each of the layers (214,216, and218) includes cylinder openings220. The cylinder openings220align with the cylinder sections (250,252,254, and256). In this way, the head gasket106enables the sections of the cylinders in both the cylinder block104and the cylinder head102to be in direct fluidic communication, thereby forming complete cylinders. Each of the layers in the head gasket106may also include a plurality of coolant openings enabling coolant to flow through the head gasket from coolant passages in the cylinder block104to coolant passages in the cylinder head102. Specifically, coolant openings in each of the layers may form a column of coolant openings extending through the head gasket106. The coolant openings and columns of coolant openings are labeled inFIGS. 3-8and discussed in greater detail herein.

The exterior block interfacing layer214may comprise embossed stainless steel with rubber coating at the embossments (e.g., sealing beads) in some embodiments. The interior layer216may comprise carbon steel and/or stainless steel. It will be appreciated that the interior layer216is not embossed in the depicted embodiment. The exterior cylinder interfacing layer218may comprise embossed stainless steel with rubber coating at the embossments (i.e., sealing beads). Thus, the interior layer216in the head gasket106may include different materials than the exterior block interfacing layer214and the exterior head interfacing layer218. It will be appreciated that the head gasket106may include additional layers that are not depicted in other embodiments. For example, the head gasket106may include a plurality of interior layers having aligned coolant openings.FIG. 3shows a top view of the exterior block interfacing layer214. The exterior block interfacing layer214includes a first set of block interfacing layer coolant openings having a plurality of coolant openings. The block interfacing layer coolant openings in the first set include a first block interfacing layer coolant opening300, a second block interfacing layer coolant opening302, and a third block interfacing layer coolant opening304. It will be appreciated that the coolant openings300,302, and304are larger than the corresponding openings in other head gasket layers. As a result, an increased amount of coolant is enabled to flow closer to the periphery of the cylinders, thereby increasing cylinder cooling. Further, it will be appreciated that coolant may be flowed from coolant passage outlets in the cylinder block, through the first set of coolant openings, and into coolant passage inlets in the cylinder head. Specifically, the first coolant opening300is adjacent to the first cylinder108and the second cylinder110, shown inFIG. 1, when the engine assembly100is assembled Likewise, the second coolant opening302is adjacent to the second cylinder110and the third cylinder112, shown inFIG. 1and the third coolant opening304is adjacent to the third cylinder112and the fourth cylinder114, shown inFIG. 1. The first, second, and third coolant openings (300,302, and304) are substantially identically in size and geometry. Therefore, it will be appreciated that the following description of the first coolant opening300also applies to the second coolant opening302and the third coolant opening304. However, alternate sizes and geometries have been contemplated.

The first block interfacing layer coolant opening300includes a first edge306traversing a first cylinder sealing bead308. The first cylinder sealing bead308extends around the periphery of the first cylinder108, shown inFIG. 1, when the engine assembly100is assembled. Sealing beads act as sealing interfaces. Thus, before the engine assembly is assembled the sealing bead308may be embossed (e.g., raised) and uncompressed. When assembled the beads may be compressed, forming a seal with the cylinder block104. The cylinder sealing bead reduces the likelihood of coolant flowing into the first cylinder and/or combustion gas flowing out of the first cylinder. The first edge306is concave. In particular, the first edge306has a curvature that is contoured to mate with a wall258, shown inFIG. 2, of the first cylinder108, shown inFIG. 1. It will be appreciated that the cylinder block104may be provided with increased cooling when the first coolant opening300is shaped in this way, thereby reducing the likelihood of thermal degradation of the cylinder block.

Likewise, the first block interfacing layer coolant opening300includes a second edge310traversing a second cylinder sealing bead312. The second cylinder sealing bead312extends around the periphery of the second cylinder110, show inFIG. 1, when the engine assembly100is assembled. The second edge310is also concave and has a curvature that is contoured to mate with a wall258, shown inFIG. 2, of the second cylinder110, shown inFIG. 1. Thus, the first block interfacing layer coolant opening300extends from the first cylinder sealing bead308to the second cylinder sealing bead312. In this way, the size of the coolant opening is increased when compared to coolant openings that do not extend between the cylinder sealing beads. As a result, cooling of the cylinder block104, shown inFIG. 2, may be increased.

Furthermore, the first block interfacing layer coolant opening300includes a third edge314that is concave. The first block interfacing layer coolant opening300is symmetric about an axis315. The symmetry enables more evenly distributed cooling to be provided to the cylinder block104, shown inFIG. 2. As a result, the likelihood of warping or other types of thermal degradation may be decreased. In the depicted embodiment, the first block interfacing layer coolant opening320is positioned between 140°-170° with regard to an axis315extending laterally through a central axis339of the first cylinder108. 90° AND 180° are provided for reference inFIG. 3. It has been found unexpectedly that when the block interfacing layer coolant openings have the aforementioned geometry a coolant flow patterns conducive to removing an increased amount of heat from the cylinder block are generated.

As shown, the first cylinder sealing bead308and the second cylinder sealing bead312include an adjoining portion319. When the sealing beads and therefore the cylinders are positioned in this way the compactness of the engine assembly100is increased when compared to engine assemblies which may have a large separation between neighboring cylinders. However, other types of cylinder spacing have been contemplated.

The exterior block interfacing layer214further includes a second set of block interfacing layer coolant openings including a fourth block interfacing layer coolant opening330, a fifth block interfacing layer coolant opening332, and a sixth block interfacing layer coolant opening334. As shown, the second set of block interfacing layer coolant openings (330,332, and334) has a similar geometry to the first set of block interfacing layer coolant openings (300,302, and304) but is positioned on an exhaust side336of the exterior block interfacing layer214. Axis338is the line dividing the exterior block interfacing layer214into an exhaust side336and an intake side340. The axis338extends through the central axes339of each of the cylinder opening220. Coolant may flow through the second set of coolant openings from coolant passage outlets in the cylinder block104to coolant passage inlets in the cylinder head102, shown inFIG. 2.

Continuing withFIG. 3, the exterior block interfacing layer214further includes bolt holes318. The bore openings are configured to accept bolts or suitable attachment apparatuses when the cylinder head102and the cylinder block104, shown inFIG. 2, are attached. The first set of block interfacing layer coolant openings (300,302, and304) and the second set of block interfacing layer coolant openings (330,332, and334) are positioned between the bolt holes318. Specifically, the block interfacing layer coolant opening300and the block interfacing layer coolant opening330are positioned between two laterally opposing bore openings and therefore the laterally opposing attachment bores202and/or bolt openings, shown inFIG. 2. Likewise, the block interfacing layer coolant openings (302and332) and (304and334) are also positioned between two laterally opposing attachment bores and/or bolt openings. A lateral axis and a longitudinal axis are provided for reference.

Additional block interfacing layer coolant openings320included in the exterior block interfacing layer214are also depicted. It will be appreciated that coolant may be flowed through the block interfacing layer coolant openings320from coolant passage outlets in the cylinder block104to coolant passage inlets in the cylinder head102, shown inFIG. 2.

A peripheral sealing bead322is also included in the exterior block interfacing layer214. The peripheral sealing bead322extends around the exterior block interfacing layer214and encloses the cylinder openings220included in the exterior block interfacing layer214. The exterior block interfacing layer214further includes a third cylinder sealing bead324and a fourth cylinder sealing bead326.

It will be appreciated that the peripheral sealing bead322, the first cylinder sealing bead308, the second cylinder sealing bead312, the third cylinder sealing bead324, and the fourth cylinder sealing bead326may be in face sharing contact with the cylinder head attachment surface200when the engine assembly100shown inFIG. 2is assembled.

FIG. 4shows a top view of the interior layer216. The interior layer216includes a first set of interior layer coolant openings including a first interior layer coolant opening400, a second interior layer coolant opening402, and a third interior layer coolant opening404. The first interior layer coolant opening400may be vertically aligned with the first block interfacing layer coolant opening300, shown inFIG. 3. Likewise, the second and third interior layer coolant openings (402and404) may each be vertically aligned with block interfacing layer coolant openings.

The interior layer216further includes a second set of interior layer coolant openings including a fourth interior layer coolant opening406, a fifth interior layer coolant opening408, and a sixth interior layer coolant opening410.

Each of the interior layer coolant openings included in the first and second sets of interior layer coolant openings have a similar size and geometry. However, the size and/or geometry may vary between the interior layer coolant openings. The first interior layer coolant opening400has a smaller cross-sectional area than the first block interfacing layer coolant opening300. The interior layer216further includes attachment sections412. The attachment sections412may be raised and configured to mate with recesses in the exterior block interfacing layer214.

FIG. 5shows a top view of the exterior head interfacing layer218. The exterior head interfacing layer include bolt holes500. The bore openings500may be configured to receive bolts or other suitable attachment devices coupling the cylinder head102to the cylinder block104, shown inFIG. 2, when assembled.

The exterior head interfacing layer218also includes a first set of head interfacing layer coolant openings including a first pair of head interfacing layer coolant openings502, a second pair of head interfacing layer coolant openings504, and a third pair of head interfacing layer coolant openings506.

The exterior head interfacing layer also comprises a second set of head interfacing layer coolant openings including a fourth pair of head interfacing layer coolant openings508, a fifth pair of head interfacing layer coolant openings510, and a sixth pair of head interfacing layer coolant openings512. Each of the head interfacing layer coolant openings included in the exterior head interfacing layer has a similar size and geometry. However, varying sizes and/or geometries have been contemplated. It will be appreciated that coolant may flow through the interior layer coolant openings from coolant passage outlets in the cylinder block shown inFIG. 2. The first pair of head interfacing layer coolant openings502is vertically aligned with the first interior layer coolant opening400and the first block interfacing layer coolant opening300. Thus, coolant may flow between the aforementioned openings. Additionally, the first pair of head interfacing layer coolant openings502has a smaller cross-sectional area than the first interior layer coolant opening400, shown inFIG. 4. Thus, the cross-sectional area of corresponding coolant openings in the head gasket106, shown inFIG. 2, decrease in a downstream direction. In the depicted embodiment, the outer head interfacing coolant opening in each pair opens to coolant inlets in the cylinder head102, thereby providing metering to the coolant entering the cylinder head102. Thus, each of the outer head interfacing coolant openings is in fluidic communication with a corresponding coolant inlet in the cylinder head. The outer head interfacing coolant openings are the coolant openings father away from the axis338. On the other hand, the inner head interfacing coolant opening in each pair are masked and do not open into coolant inlets in the cylinder head102. The inner head interfacing coolant opening in each pair provide a larger column of water to extract heat from the cylinder block104. However in other examples, both openings in each pair of head interfacing coolant openings may provide metering to coolant entering the cylinder head102.The pairs of head interfacing layer coolant openings are also laterally aligned. However, other alignments have been contemplated.

The head interfacing layer218includes additional head interfacing layer coolant openings514configured to flow coolant therethrough to coolant passage inlets included in the cylinder head102, shown inFIG. 2.

FIG. 6shows the exterior block interfacing layer214and the interior layer216assembled. As shown, the cross-sectional area of the first block interfacing layer coolant opening300is larger than the cross-sectional area of the first interior layer coolant opening400. The increase in cross-sectional area may be due at least in part to manufacturing constraints. Moreover, the first block interfacing layer coolant opening300and the first interior layer coolant opening400are vertically aligned. Additionally, first interior layer coolant opening400and the first block interfacing layer coolant opening300at least partially overlap one another. It will be appreciated that the first pair of head interfacing layer coolant openings502, shown inFIG. 5, and the first interior layer coolant opening400may also at least partially overlap one another.

FIG. 7shows a cross-sectional view of the assembled head gasket106. The exterior block interfacing layer214, the interior layer216, and the exterior head interfacing layer218. The block interfacing layer coolant opening330, the interior layer coolant opening406, and the pair head interfacing layer coolant openings508form a column of coolant openings700. It will be appreciated that coolant may flow through the column of coolant openings700. The block interfacing layer coolant opening330may be in direct fluidic communication with the interior layer coolant opening406and the interior layer coolant opening406may be in direct fluidic communication with the pair head interfacing layer coolant openings508. It will be appreciated that direct fluidic communication is defined as flowing fluid directly from one component to another without any intervening components positioned therebetweeen.

Arrow704denotes the general flow of coolant from the one of the coolant passage outlets232in the cylinder block104, shown inFIG. 2, to the column of coolant openings700. Likewise, arrow702denotes the general flow of coolant from the column of coolant openings700to a coolant passage inlet814in the cylinder head102, shown inFIG. 8. It will be appreciated that coolant flow into and out of the column of coolant openings may have additional complexity that is not depicted. Moreover, each of the aligned coolant openings in layers of the head gasket may form similar columns of coolant openings.

FIG. 8shows a bottom view of the cylinder head102, shown inFIG. 2. The cylinder head102includes a cylinder block attachment surface801having attachment bores803. The attachment bores803are configured to receive bolts, dowels, or other suitable attachment apparatuses that may couple the cylinder head102to the cylinder block104, shown inFIG. 2. Therefore, in some examples, the attachment bore803may be bolt openings. The cylinder block attachment surface801may be in contact with a portion of the exterior head interfacing layer218, when the engine assembly100, shown inFIG. 2is assembled.

Continuing withFIG. 8, the cylinder head102also includes a first cylinder section800, a second cylinder section802, a third cylinder section804, and a fourth cylinder section806. It will be appreciated that the first cylinder section800is included in the first cylinder108, shown inFIG. 1. Likewise, the second cylinder section802is included in the second cylinder110shown inFIG. 1, the third cylinder section804is included in the third cylinder112, and the fourth cylinder section806is included in the fourth cylinder114. The cylinder head102further includes a first set of coolant passage inlets including a first coolant passage inlet808, a second coolant passage inlet810, and a third coolant passage inlet812.

The cylinder head102additionally includes a second set of coolant passage inlets including a fourth coolant passage inlet814, a fifth coolant passage inlet816, and a sixth coolant passage inlet818. It will be appreciated that the first and/or second set of coolant passage inlets may be included in the plurality of coolant passage inlets140, shown inFIG. 1. Coolant may flow from the outer opening in the first pair of head interfacing layer coolant openings502, shown inFIG. 5, to the first coolant passage inlet808, during operation of the cooling system120, shown inFIG. 1. Likewise, the second coolant passage inlet808receives coolant from the outer opening in the second pair of head interfacing layer coolant openings502, shown inFIG. 5. It will be appreciated that the third, fourth, fifth, and sixth coolant passage inlets (812,814,816, and818) receive coolant from the outer openings in each of the third, fourth, fifth, and sixth pairs of head interfacing coolant openings (506,508,510, and512), shown inFIG. 5.

Additional coolant passage inlets820are shown inFIG. 8. It will be appreciated that the additional coolant passage inlets820receive coolant from openings in the head gasket106, shown inFIG. 2.

FIG. 9shows a method900for operating an engine cooling system. The method900may be implemented via the engine assembly and components described above with regard toFIGS. 1-8or may be implemented by other engine assemblies and components.

The method includes at902flowing coolant from an outlet of a cylinder head coolant passage to a column of coolant openings extending through a head gasket and adjacent to neighboring cylinders in the engine, the cross-sectional area of the column of coolant openings decreasing in a downstream direction. Flowing coolant through the column of coolant openings may includes flowing coolant through a block interfacing layer coolant opening included in an exterior block interfacing layer, an interior layer coolant opening included in an interior layer, and a head interfacing layer coolant opening included in an exterior head interfacing layer. In some examples, the block interfacing layer coolant opening may extend from a first cylinder sealing bead extending around the periphery of the first cylinder to a second cylinder sealing bead extending around the periphery of the second cylinder.

Next at904the method includes flowing coolant through the column of coolant openings and at906the method includes flowing coolant from the column of coolant openings to an inlet of a cylinder block coolant passage.

This concludes the description. The reading of it by those skilled in the art would bring to mind many alterations and modifications without departing from the spirit and the scope of the description. For example, single cylinder, I2, I3, I4, I5, V6, V8, V10, V12 and V16 engines operating in natural gas, gasoline, diesel, or alternative fuel configurations could use the present description to advantage.