Abstract: A gasket includes an elastic part containing a rubber having a dynamic-to-static ratio, Kd/Kst, of 2.5 or lower, wherein the dynamic-to-static ratio, Kd/Kst, is a ratio between a dynamic spring constant, Kd, and a static spring constant, Kst. The dynamic spring constant, Kd, represents a constant as measured under conditions of 23±2° C., 100 Hz, and a strain amplitude of 0.1% according to JIS K6394:2007, and the static spring constant, Kst, represents a constant as measured under conditions of 23±2° C. and a strain amplitude of 0.1% according to JIS K6394:2007.

Abstract: This surface treatment agent using a compound represented by formula (1) or (2) can, even without having a hydrolyzable group, form a water repellent and oil repellent layer having excellent abrasion resistance under mild conditions such as at room temperature. [Rf represents a monovalent or divalent fluorooxyalkylene group-containing polymer residue, Y1 and Y2 each represent a single bond or a divalent hydrocarbon group, Q represents a group that has a Si-containing structure having a valence of 2-4, Si, or C, X represents an epoxy-containing group, k represents 0-2, m represents 1-5, n represents 1-3, Z represents H, —SiR3 (R represents an alkyl group or a phenyl group), or —W1-Q?-W2—X? (X? represents X or —SiR3, W1 and W2 each represent a single bond or a divalent hydrocarbon group, Q? represents a divalent group having a Si-containing structure), and ? represents 1 or 2].

Abstract: A gasket for a combustion chamber is provided. The gasket comprises an upper assembly including an upper combustion sealing section with a raised bead positioned between a first component and a second component adjacent to a combustion chamber and an upper fluid sealing section positioned between the first component and the second component at a location spaced away from the combustion chamber. The upper combustion sealing section includes an anti-fret coating on a metal layer, the upper fluid sealing section includes a synthetic rubber coating on a metal layer, and the upper combustion sealing section is greater in thickness than the upper fluid sealing section.

Abstract: A multi-layer head gasket having at least two active layers and a shim layer sandwiched there between. The gasket and shim layer include cylinder openings aligned with the cylinders disposed within an engine block. The shim layer incorporates a plated portion for adding topography to an otherwise flat shim layer, the areas of plating determined based on FEA and/or pressure film load testing, for improving fatigue resistance, sealing pressure, and/or loading characteristics of the gasket.

Abstract: A gasket for a combustion chamber is provided. The gasket comprises a plated surface extending across at least a portion of the metal base. In the gasket, at least a portion of the plated surface includes a laser treated section with a first raised surface that protrudes away from the metal base and the laser treated section is arranged in a mid-span that is arranged between two cylinder openings.

Abstract: An upper gasket member includes an upper base portion of an annular flat plate, an upper outer periphery portion diagonally extending to an upper side from an outer periphery edge portion of the upper base portion, and an upper outer periphery side annular portion of an annular flat plate extending in an extension direction of the upper base portion from an outer periphery edge portion of the upper outer periphery portion. Further, a lower gasket member includes a lower base portion of an annular flat plate, a lower outer periphery portion diagonally extending to a lower side from an outer periphery edge portion of the lower base portion, and a lower outer periphery side annular portion of an annular flat plate extending in an extension direction of the lower base portion from an outer periphery edge portion of the lower outer periphery portion.

Abstract: A gasket assembly includes a gasket body, an adhesive-backed film, and a plurality of grommets. The gasket body includes a first face, and the adhesive-backed film includes a sticky face bonded to the first face of the gasket body. The grommets are bonded to the sticky face of the adhesive-backed film.

Abstract: A metal gasket includes: a straight section provided with a bolt hole; a bead section raised from an inner peripheral edge of the straight section toward one side of the direction of the thickness of the gasket; and a bent section bent from an outer peripheral edge of the straight section toward the other side of the direction of the thickness of the gasket. When metal gasket is compressively sandwiched by a pair of housings, bead section elastically deforms to decrease height, and straight section elastically deforms, whereby the inner peripheral edge of the straight section contacts one of the housings, the outer peripheral edge of the straight section contacts the other housing, and the bent section contacts the one of the housings. A gasket installation determination projection is part of the periphery and provided on the outer peripheral edge of the bent section or of the straight section.

Abstract: A metal gasket (10) installed between a cylinder head and a cylinder block comprises at least one metal substrate (11) coated with a sealant (19) on its outer surface, and including a full bead (13) for cylinder bore hole sealing and a half bead (16) for liquid hole sealing. The half bead (16) includes: an inclined plate portion (16b) connected to a flat substrate body (11a) of the metal substrate (11) through a first bend portion (16a) and inclined with respect to the substrate body (11a); and an edge plate portion (16d) connected to the inclined plate portion (16b) through a second bend portion (16c) and inclined with respect to the inclined plate portion (16b). A radius at a convex surface of the first bend portion (16a) and a radius at a concave surface of the second bend portion (16c) are in a range of 2.0 mm to 3.5 mm.

Abstract: An extrusion resistant gasket may have a metallic core having a first side and a second side. The metallic core may have a plurality of alternating domes and valleys integrally formed therein. The domes and valleys do not have perforations through the core. The gasket may also have a non-metallic facing material on at least one of the sides of the metallic core. The facing material may have a contact surface and an inner surface. The domes or valleys do not extend through the contact surface.

Abstract: A device includes a cover and a base. The base is coupled to the cover to create an enclosure. The device also includes a form-in-place-gasket. The form-in-place-gasket is positioned between the cover and the base to create a seal. The form-in-place-gasket includes an acid-absorbing material.

Abstract: A metal gasket which enables improvement of sealing properties by making sufficient compression of a full bead possible even if elastic coating is formed along the full bead. In the gasket (1) having a full bead (13), formed on a metal substrate (10), having a mountain-shaped protruding surface formed on one side in a thickness direction and a valley-shaped recessed surface formed on the other side in the thickness direction, elastic coating (20) is formed on the whole surface of the protruding surface of the full bead (13), and the elastic coating (20) is formed on the recessed surface of the full bead (13), except a slit-shaped elastic coating-free section (14) along a bottom section (13a) of the recessed surface.

Abstract: A purge control solenoid valve includes a gas access body including an evaporation gas inlet, an evaporation gas outlet, and a path that connects the evaporation gas inlet and the evaporation gas outlet; a valve operation body including an armature coupled to the gas access body and performing a reciprocating motion in a direction in which the armature is brought into close contact with or separated from the path by a core that generates a magnetic force; and an armature top member being in close contact with or separated from the path due to the reciprocating motion of the armature to open or close the path. The armature top member has a non-adhesion coating formed on a top surface of a body thereof, and the non-adhesion coating includes a binder, graphite, polytetrafluoroethylene, and a crosslinking agent.

Abstract: A metal gasket containing a metal plate having an opening portion and having a seal bead having a bent cross-sectional shape formed along the opening portion in order to suppress a variation in the height of the seal bead due to a tensile stress generated in the outer periphery of the seal bead in the molding of the seal bead is provided with a lightening hole extending along the outer periphery of the seal bead, in which the distance between the lightening hole and the seal bead is constant.

Abstract: A manifold gasket includes two or more metal plates laminated together to form the manifold gasket, a plurality of bores formed in the metal plates, a plurality of annular seal portions, each surrounding each of the plurality of bores to seal therearound, a plurality of bolt holes disposed at an outer periphery of each of the plurality of annular seal portions so that fastening bolts are inserted therethrough, and a partition protector having a thermal deformation coping portion, located in the two or more metal plates between two of the bores. The thermal deformation coping portion includes offset slits in each metal plate such that none of the slits are aligned in a lamination direction of the thermal deformation coping portion, and such that the slits prevent damage to the manifold gasket due to temperature fluctuations by accommodating thermal expansion or contraction of the manifold gasket.

Abstract: A cylinder head gasket includes a composite member formed of a metal substrate and a rubber layer provided to both surfaces of the substrate. The substrate is formed of stainless steel having a content of C that is 0 to 0.15 mass %, a content of Si that is 0 to 0.5 mass %, a content of Mn that is 0 to 2.0 mass %, a content of Cr that is 11.5 to 13.0 mass %, a content of N that is 0 to 0.5 mass %, a content of P that is 0 to 0.040 mass %, a content of S that is 0 to 0.030 mass %, a content of Ni that is 0 to 0.6 mass %, the balance Fe, and inevitable impurities. The stainless steel forming the substrate has a 0.2% proof stress of 1,300 to 1,500 MPa.

Abstract: A transmission case (10) includes a case (2) and a side cover (3). A rotation sensor (5) including a connector terminal part (52) is attached to the side cover (3). A seal member (FIPG) (4) is interposed between joining surfaces (22a, 32a) of the case (2) and the side cover (3). A notch portion (25) where the seal member (4) is accumulated is provided to an outer peripheral surface (22b) of the joining surface (22a) which is adjacent to the connector terminal part (52). Accordingly, the amount of the seal member (4) protruding outward from the outer peripheral surface (22b, 32b) of the flange portions (22, 32) is reduced, thus suppressing connection failure of a connector.

Abstract: A cylinder head gasket includes two or more metal plates laminated together to form the cylinder head gasket, a plurality of cylinder bores formed in the metal plates, a plurality of annular seal portions, each surrounding each the plurality of cylinder bores to seal therearound; a plurality of bolt holes disposed at an outer peripheral side of the plurality of annular seal portions so that fastening bolts are inserted therethrough, and a partition protector having a thermal deformation coping portion, located in the two or more metal plates between two of the bolt holes. The thermal deformation coping portion includes offset slits in each metal plate such that none of the slits are aligned in a lamination direction of the thermal deformation coping portion. The slits prevent damage to the cylinder head gasket due to temperature fluctuations by accommodating thermal expansion or contraction of the cylinder head gasket.

Abstract: A method of forming a seal plate for sealing between two components of an assembly includes forming a plate element from a first material, the plate element including at least one seal groove receptive of a seal element and forming a seal element from a second material different from the first material by one or more additive manufacturing processes, the second material an elastomeric material of a selected durometer. The seal element is affixed to the plate element at the seal groove. A seal plate includes a plate element having one or more seal grooves receptive of a seal element, the plate element formed from a first material. A seal element is installed into the seal groove, the seal element formed from a second material different from the first material by one or more additive manufacturing processes, the second material an elastomeric material of a selected durometer.

Abstract: A disgregating device of biological material, comprising: a hollow outer body, defining an inner chamber; a fixed disgregating grid, having a plurality of microholes provided with sharp edges, and housed transversely in the inner chamber so as to define an upper loading chamber apt to be loaded with the biological material to be disgregated and a lower collecting chamber apt to collect the biological material, after it has been disgregated; and a bladed rotor, rotating in the inner chamber, apt to co-operate, rotating, with the fixed disgregating grid, so as to feed and bring the biological material, contained in the upper loading chamber, into contact with the microholes of the disgregating grid and therefore cause the disgregation of the biological material making it pass through these microholes.

Abstract: An object of the present invention is to provide a gasket capable of improving cooling efficiency with a simpler configuration while keeping performance of the gasket and a manufacturing method thereof. A gasket includes a first annular portion which is formed by a metal wire woven fabric obtained by weaving a first metal wire and includes a seal target hole and a main body portion which is in contact with an outer peripheral edge of the first annular portion, in which the first metal wire forming the first annular portion and the first metal wire forming the main body portion are entangled with each other and a second metal wire is woven together with the first metal wire forming the first annular portion to form the first annular portion as a high thermal conduction region.

Abstract: A gasket and a method for manufacturing thereof which can improve durability by maintaining a surface pressure over a long period of time is provided. A gasket is formed by a first annular portion including a sealing object hole formed by a metal wire weave wherein a metal wire is braided; and a main member portion contacting an outer circumferential edge of the first annular portion. A metal wire forming the first annular portion and a metal wire forming the main member portion are respectively interlaced, and a compressive stress in an x direction of the metal wire weave forming the first annular portion differs from a compressive stress in the x direction of the metal wire weave forming the main member portion.

Abstract: A gasket includes a first compressible portion, a second incompressible portion integrally formed with the first compressible portion, and a flexible coating disposed on one or more of the first compressible portion and the second incompressible portion. The first compressible portion is substantially planar and includes a plurality of layers, and the second incompressible portion is substantially planar and includes a first of the plurality of layers.

Abstract: A metal static gasket and method of construction thereof is provided. The gasket includes at least one metal layer. The at least one metal layer has opposite sides with at least one through opening extending through the opposite sides configured to register with an opening to be sealed and at least one raised annular seal bead extending at least in part about the at least one through opening. At least one protrusion extends outwardly from at least one of the sides, wherein the at least one protrusion prevents complete flattening of the at least one seal bead. The at least one protrusion has a plurality of discrete layers of metal deposited on one another via an additive manufacture process, wherein the protrusion is formed having a hollow region extending therein.

Abstract: A gasket formed by laminating two or more metal plates includes a seal target hole, an annular seal portion sealing an outer peripheral edge of the seal target hole, and a plurality of bolt holes disposed at the outer peripheral side of the seal portion. Each metal plate constituting a thermal deformation coping portion is provided with slits intersecting in a longitudinal direction of the metal plate and each slit constitutes a lamination portion of the metal plate so as not to penetrate in a lamination direction. When one seal target hole is provided, a portion suspended in the seal target hole is formed at the thermal deformation coping portion, and when multiple seal target holes are provided, at least one of portions interposed between the adjacent seal portions and a portion interposed between the adjacent bolt holes is formed at the thermal deformation coping portion.

Abstract: A gasket is provided comprising a composite insulating component and a bonding resin. The insulating component is a ceramic abrasive and the bonding resin is a phenolic thermoset resin. The composite insulating component is selected from the group of alumina, zirconia, or silicon carbide. The gasket further comprises a reinforcing fiber selected from the group of glass, ceramic, aramid, or PAN fibers.

Abstract: Provided is a method for manufacturing a gasket-constituting plate made of metal, in which a folded-back part whose thickness is set to be less than the thickness of a general part is provided at a periphery of a combustion chamber hole. The method includes, with a raw metal plate being held between a blank holder and a drawing die having an extrusion hole, extruding the raw metal plate in a thickness direction thereof by using a drawing punch as an extrusion tool to form a projecting part in the raw metal plate, and causing a tensile force to act on the raw metal plate due to the extrusion so as to elongate the raw metal plate, to form a thin peripheral wall part at an outer peripheral portion of the projecting part.

Abstract: A gasket including a sheet part that includes exfoliated clay minerals, wherein the exfoliated clay minerals are irregularly dispersed in the sheet part without being oriented.

Abstract: A gasket capable of surely preventing leakage of a fluid, without deteriorating a sealing performance even when a situation of fall of surface pressure at a periphery edge of a through hole occurs is provided.

Abstract: A composition for forming fire resistant concrete block, that includes a cementitious binder material comprising alumina cement, recycled fine aggregate, and recycled coarse aggregates, the recycled fine aggregates including 10-50 wt % recycled particulate glass cullet having a particle size of 600 microns or less, a concrete block formed from the composition exhibiting a decrease in thermal conductivity with increasing temperature at temperatures causing the particulate glass cullet to melt. A concrete block fabricated from the composition exhibits a fire resistance of at least three hours, a density below 2000 kg/m3, and a compressive strength of at least 7 MPa.

Abstract: A gasket includes a plurality of metal plates laminated together, and having a plurality of through holes situated adjacent to each other, and seal structures each annularly surrounding each of the through holes. Each of the seal structures includes a first seal bead adjacent to one through hole and a second seal bead situated outside the first seal bead relative to the one through hole, a first seal portion located in a first area between adjacent two through holes, and a second seal portion located in a second area other than the first area. The first seal portion has an annular width narrowing as outside ends of the first seal portion come close to a center of the first seal portion by locating the second seal bead close to the first seal bead, and the second seal portion has an annular width constant in an annular circumferential direction.

Abstract: A gasket includes at least one metal plate formed of a martensitic stainless steel plate and clamped between two members fastened by fastening devices, a cylinder bore provided in the metal member, a seal bead protruding outwardly from a flat surface of the metal plate, and annularly surrounding the cylinder bore, the seal bead having a top portion and two side portions arranged at two sides of the top portion, and insertion holes for the fastening devices to pass through, provided around the cylinder bore. The seal bead has a high hardness portion having a hardness higher than that in a portion of the metal plate other than the high hardness portion. The high hardness portion has a thickness gradually reduced toward a boundary between the high hardness portion and the portion other than the high hardness portion.

Abstract: A gasket includes at least one metal plate to be clamped between two members fastened by fastening devices, an opening portion corresponding to a sealing hole provided in the at least one metal member, a seal bead protruding outwardly from a flat surface of the at least one metal plate, and annularly surrounding the opening portion, and insertion holes through which the fastening devices pass. At least one metal plate is formed by a martensitic stainless steel plate, and a high hardness portion having a hardness higher than that of the stainless steel plate is formed in at least one portion of the seal bead formed in the stainless steel plate.

Abstract: A seal arrangement includes a body having at least two walls defining a cavity, the walls are engagable with at least one structure through expansion of the body, and graphite is sealingly engaged with the body and the structure and resiliently compressively maintained within the cavity by the at least one structure.

Abstract: An insulation gasket that includes a metal core (100) defining an inner serrated annular section (105) that is radially spaced from an outer serrated annular section (110); and an annular groove (115) formed between the inner and outer serrated annular sections; and a first material (135) accommodated in the annular groove (115). In certain embodiments, a second material (125) engages the inner serrated annular section (105); and a third material (130) engages the outer serrated annular section. In one embodiment, the first and second materials comprise an electrical insulation material and the third material comprises a fire safe material.

Abstract: In a tabular metal gasket having a plurality of bolt holes, a seal bead is provided between bolt holes which are adjacent to each other, one end of the seal bead is connected to the one bolt hole and the other end of the seal bead is connected to the other bolt hole. The seal bead is formed into a gradually changing shape in which a width is the narrowest at the center portion between the bolt holes and the width is gradually enlarged from the center portion between the bolt holes toward the bolt holes, and satisfies the following expression (a): D>d?W1 in which D is a diameter of a head seat surface of a fastening bolt which is inserted into the bolt hole, d is a diameter of the bolt hole, and W1 is the maximum width of the seal bead.

Abstract: Provided is a shaft seal device provided with a seal member which possesses excellent liquid tightness, small friction resistance and high wear resistance. In a shaft seal device which is arranged around the periphery of a shaft which is supported in a rotatable manner or in a reciprocating manner, and is provided with a seal member for securing liquid tightness around the shaft, the seal member is formed of a porous body formed by using a hydrophilic polymer resin in which chains are cross-linked. The shaft seal device is also characterized in that: the shaft is a shaft which extends between a liquid phase region and a gas phase region; the seal member is a seal member which suppresses a leakage of a liquid to the gas phase region from the liquid phase region; and an aqueous lubricant which is prepared by adding a water soluble thickening agent is impregnated into the seal member.

Abstract: A method of making a gasket having a high temperature coating that includes obtaining a substrate formed from a metallic material and having the shape of a gasket, applying a nanoparticle suspension over the outer surfaces of the substrate, and heating the substrate to a first elevated temperature to form an undercoat layer of a self-protective oxide coating. The method also includes applying a liquid comprising boron nitride over the undercoat layer and drying the boron nitride liquid at a second elevated temperature to form an overcoat layer.

Abstract: A gasket includes: a spiral wound gasket; a first O-ring member located inner side of the spiral wound gasket; a second O-ring member located outer side of the spiral wound gasket; a first core spring located inside the first O-ring member; a second core spring located inside the second O-ring member; a first jacket formed with an opening portion and accommodating the spiral wound gasket, the first O-ring member, and the second O-ring member inside thereof through the opening portion; a second jacket formed with an opening portion at the one end thereof and accommodating the spiral wound gasket, the first O-ring member, and the second O-ring member, and the first jacket inside thereof through the opening portion; a first sealing layer being formed on the first jacket; a second sealing layer to cover the first sealing layer; and a third sealing layer being formed on the second jacket.

Abstract: A seal structure has a metal gasket arranged between a pair of casings. The metal gasket is provided with a bead portion in an inner peripheral side of a planate outer peripheral portion, and a bent portion in an outer peripheral side. When the metal gasket is pinched by a pair of casings, the bead portion elastically deforms so as to reduce its height and the outer peripheral portion elastically deforms on the basis of the elastic deformation of the bead portion, and comes into contact its outer peripheral end portion with one casing, whereby any gap in which salt water stays is not formed between one casing and the outer peripheral portion, and the bent portion comes into contact with the other casing, whereby any gap in which the salt water stays is not formed between the other casing and the outer peripheral portion.

Abstract: A spiral-wound gasket for use in a HF alkylation unit and positioning between facing conduit flanges includes an outer ring, an inner ring, and low-compression spiral-wound portion positioned between the outer ring and the inner ring.

Abstract: A cylinder head gasket including a first functional layer, a second functional layer, a first stopper, and a second stopper is provided. The first functional layer includes a first full bead extending around a combustion chamber opening and axially aligned with a second full bead of the second functional layer. The first stopper extends along the first functional layer between the combustion chamber opening and the first full bead for preventing over-compression of the first full bead. The second stopper extends along the second full bead of the second functional layer for increasing load on the second full bead, reducing head lift, and promoting an even distribution of the load. The second stopper includes a third full bead matching the second full bead of said second functional layer.

Abstract: A sealing configuration is configured for sealingly coupling a first fluid flow path of a first device to a second fluid flow path of a second device. The sealing configuration comprises a contact surface comprising a structure configured for increasing a surface pressure when coupling the first device to the second device. The contact surface comprises a metal coating configured for increasing sealing.

Abstract: A cylinder head gasket includes a metallic gasket layer having through-openings and, at its peripheral outer margin, a first sealing element for providing a seal. The first sealing element forms a sealing line extending circumferentially about the gasket layer and surrounding the through-openings. The side of the first sealing element facing away from the peripheral outer margin of the gasket layer includes a vent hole arranged adjacent to a sealing line break and located in a first gasket layer region which is, on only a first side of the gasket layer, on both sides of the sealing line break, continuously bounded by the first sealing element and a second sealing element. The first sealing element and the second sealing element extend around the first gasket layer region such that a fluid flow path extending from the sealing line break to the vent hole has at least one change in direction.

Abstract: A multi-layer cylinder head gasket providing improved sealing performance, stability, and a more rigid joint between two components is provided. The gasket includes a plurality of functional layers each including a full bead located between an inner edge and outer edge and surrounding a combustion chamber opening. A stopper is disposed between the functional layers and is located radially between the combustion chamber opening and the full bead. A coating material is applied to at least one surface of at least one functional layer and extends along a majority of the length of the functional layer. To achieve the improved performance, a region along the surface located between the inner edge and the full bead remains uncoated, or includes a reduced amount of the coating material. Alternatively, the stopper can be located between the combustion chamber opening and the inner edges of the functional layers to provide the uncoated region.

Abstract: A spherical annular seal member 34 includes a spherical annular base member 32 defined by a cylindrical inner surface 28, a partially convex spherical surface 29, and annular end faces 30, 31, as well as an outer layer 33 formed integrally on the partially convex spherical surface 29. The spherical annular base member 32 includes a reinforcing member 5 made from a metal wire net 4 and a heat-resistant material 6 containing expanded graphite and a phosphate and integrated with the reinforcing member 5 in mixed form, and the outer layer includes the heat-resistant material 6 containing the expanded graphite and the phosphate and the reinforcing member 5 made from the metal wire net 4 integrated with the heat-resistant material 6 in mixed form, the expanded graphite in the heat-resistant material 6 having an ash content of not more than 0.1% by mass and a graphite content of not less than 99.7% by mass.

Abstract: A component to be repaired includes a relatively rigid plate. On a surface that may have been subject to fracture, a resin material is first laid down, then a relatively flexible material is positioned outwardly of the resin material to repair the barrier. A part may also be formed initially with the flexible material. In another feature of this application, a method of forming a barrier includes providing a composite material, and applying a relatively flexible material on a surface of the composite material, and concurrently molding the relatively flexible material with the composite material using a composite mold.

Abstract: A cylinder head gasket with a single layer carrier member, a sealing ring for sealing around the cylinder opening, and at least one protection layer. The sealing ring has a plurality of functional layers. A protection layer is positioned on at least one side of the sealing ring, and preferably on both sides. The sealing ring and protection layers are fixedly secured to the carrier member by welding.

Abstract: A multi-layer cylinder head gasket is provided. The cylinder head gasket includes a plurality of layers of material, each of the layers has a plurality of openings including at least one cylinder bore opening and at least one pushrod opening. Each of the layers has an edge which surrounds the at least one pushrod opening, and the pushrod openings of the layers are aligned axially with one another. An eyelet extends axially in each of the pushrod openings and covers the edges of the layers for protecting a pushrod extending through the respective pushrod opening. The eyelet is made of a material that is softer than the material of the plurality of layers.

Abstract: 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.