Abstract: A valve assembly for an engine includes a gas exchange valve, a valve guide, and a seal. The gas exchange valve includes a valve stem. The valve guide includes an outer surface having a stem seal retention surface disposed at a seal end thereof. The valve stem extends through the valve guide such that the valve is reciprocally movable over a range of travel along the longitudinal axis with respect thereto. The seal is mounted to the stem seal retention surface of the valve guide such that the seal is in running, sealing engagement with the valve stem. The stem seal retention surface includes a shoulder surface to help retain the seal.

Abstract: Provided is a roll over fuel-vapor valve is provided including a housing defining a valve having a valve inlet port extending through a wall of the housing and a valve outlet port and a float member disposed between the inlet port and the outlet port and being displaceable between an open position and a closed position the hosing further comprising a fluid flow channel extending along a top portion thereof and having a first end and a second end, wherein the outlet port extending into the channel such that in the open position fluid flow is facilitated between the valve inlet port and the channel.

Abstract: A rotary valve seal for a coolant control valve is provided that offers improved sealing with a rotary valve body. The rotary valve seal includes a central axis, a cylindrical seal body, and a seal skeleton. The cylindrical seal body has a first stiffness and a first end that is configured with a radially outwardly extending flange. The seal skeleton, having a second stiffness and embedded within the cylindrical seal body, has a plurality of fingers circumferentially arranged within the flange. The second stiffness can be greater than the first stiffness. The plurality of fingers and flange can define alternating stiffness zones. The first end of the seal body and the flange define a bottom surface configured for sealing engagement with a rotary valve body. The rotary valve body can be shaped in the form of at least one spherical segment.

Abstract: A gasket is described configured to be mounted on a valve of an internal combustion engine, having a central axis and comprising: an annular elastically deformable sealing element, having a radially internal surface having a first portion, adapted to cooperate with contact with a stem of the valve, and a second portion, configured to cooperate with contact with a guide element in a sliding manner of the aforementioned stem; and an annular support member, arranged coaxially on at least part of the sealing element so that the latter is pressed radially between the support member and the valve; the second portion has a circumferential surface section and a plurality of discrete bumps, projecting cantilevered from the circumferential surface section so as to cooperate with contact in use with the guide element, angularly spaced from each other around the axis and forming a discontinuous undulation of the radially internal surface.

Abstract: A valve stem seal with significantly improved sealing performance while improving workability when fitting the valve stem seal to a valve stem guide. An inner peripheral surface of a fitting section 20B is provided with a plurality of annular seal protrusions which respectively include first inclined surfaces 25a and 26a each having a diameter that increases from a radially inward tip toward a seal section 20A side, and second inclined surfaces 25b and 26b each having a diameter that increases from a radially inward tip toward a side opposite to the seal section 20A. The first seal protrusion 25 which is closest to the seal section 20A is configured so that an inclination of the second inclined surface 25b is smaller than that of the first inclined surface 25a, and the second seal protrusion 26 which is farthest from the seal section 20A is configured so that an inclination of the first inclined surface 26a is smaller than that of the second inclined surface 26b.

Abstract: A valve stem seal hermetically seals a space formed between a valve stem of a valve which establishes and interrupts communication between a cylinder and a port and a valve guide into which the valve stem is inserted in a reciprocally movable manner, wherein the valve stem seal includes: a reinforcing ring formed into an annular shape centered about an axis, and extending in a radial direction of a ring of the reinforcing ring; and an elastic body portion formed into an annular shape centered about the axis, attached to the reinforcing ring, and including a seal lip which abuts on the valve stem.

Abstract: It is described a gasket for a valve of an internal combustion engine having a central axis and comprising: an elastically deformable sealing element having an annular shape with respect to the aforesaid axis and adapted to be externally arranged on the valve, and a support element, also having an annular shape with respect to the aforesaid axis, coaxially arranged on at least part of the sealing element so that this latter is radially pressed between the support element and the valve; the support element having, along its side wall, at least one through window to allow the evacuation of the heat generated in use during the operation of the valve.

Abstract: Methods and systems are provided for a valve spring retainer of a valvetrain assembly. In one example, valve spring retainer may be at least partially hollowed and include inner cavities forming channels within a material of the valve spring retainer. Air inside the inner cavities may be fluidly coupled to air surrounding the valve spring retainer through channels. A mass of the valve spring retainer may be decreased and a cost and speed of fabrication of the valve spring retainer may be reduced by additive manufacturing.

Abstract: It is described a gasket for a valve of an internal combustion engine, having an axis and comprising an annular sealing element to be externally arranged on the valve and an annular support element, coaxially arranged on the sealing element to press it radially on the valve; the support element comprising a first annular component, internally cooperating with the sealing element, a second annular component, coaxially surrounding the first component, and snap coupling means between these components; the second component comprising an annular main body and an outer annular end flange; the main body further having an annular edge projecting towards the axis and defining an axial abutment for the first component; the snap coupling means comprising two or more hooking projections angularly equidistant about the axis, cantileverly extending from the annular edge towards the flange and cooperating in contact with the first component to abuttingly keep it against the annular edge.

Abstract: A valve stem seal assembly has an elastomeric seal with first and second radially inwardly directed sealing lips that are in intimate sealing contact with a valve stem. The assembly also has a metal seal retainer with a first metal seal retainer portion that has a surface axially slanted inward and downward from a top of the elastomeric seal. This slanted portion forms a metal frustoconical foundation with a second metal seal retainer portion that directly radially extends from the metal frustoconical foundation. The axially slanted inward surface of the metal retainer is directly radially outward from the radially inwardly directed first sealing lip.

Abstract: Embodiments relate to a seal for sealing a valve shaft in an internal combustion engine. The seal includes a sealing lip of an elastomer which is configured to be in contact with a shell surface of the valve shaft perpendicular to a radial direction. The seal further includes a supporting structure firmly connected to the sealing lip and made of a material different from the elastomer of the sealing lip which is configured to create a form-fit in the axial direction directly between the supporting structure and a guide element of the valve shaft by an at least partial plastic deformation in the radial direction.

Abstract: Provided is a roll over fuel-vapor valve is provided including a housing defining a valve having a valve inlet port extending through a wall of the housing and a valve outlet port and a float member disposed between the inlet port and the outlet port and being displaceable between an open position and a closed position the hosing further comprising a fluid flow channel extending along a top portion thereof and having a first end and a second end, wherein the outlet port extending into the channel such that in the open position fluid flow is facilitated between the valve inlet port and the channel.

Abstract: A ball valve assembly includes a housing having a valve chamber with an inlet opening and an outlet opening. A dynamic seal assembly including a spring member and a seal member are disposed in a seal chamber in one of the inlet opening and the outlet opening, wherein the spring member biases an end portion of the seal member into the valve chamber. A valve member includes a partially spherical outer surface with a recessed cam feature extending from the outer surface and a valve opening disposed in the outer surface, wherein during assembly of the valve member in the valve chamber the recessed cam feature is aligned with the end portion of the seal member and the valve member is rotated to engage the outer surface of the valve member with the end portion of the seal member.

Abstract: There is described a gasket for a valve of an internal combustion engine; this gasket has a central axis and comprises: an elastically deformable annular seal element; a support member made of plastic material, also annular and having at least a retention portion coupled coaxially on a first portion of the seal element to press it on a guide element of the valve; and elastic means acting on a second portion of the seal element to press it on a stem of the valve; the elastic means comprise a thrust portion of the support member made in one single piece with the retention portion; the seal element is formed by means of an injection molding operation in a molding chamber containing the support member.

Abstract: A gasket for a valve of an internal combustion engine is described. The valve has a guide element defining a through seat, and a stem movable in a sliding manner in said seat. The gasket has a central axis and comprises: an elastically deformable sealing element, having an annular configuration with respect to the axis and suitable to be arranged externally on the valve to cooperate both with the guide element and with the stem; a supporting member having an annular configuration, arranged coaxially on at least part of the sealing element so that the latter is pressed radially between the supporting member and the valve; an end flange projecting radially outwards from the supporting member and configured to receive the elastic load of a coil spring of the valve; and protruding means distinct from the flange, projecting outwards from the supporting member and suitable to cooperate with the spring of the valve to maintain it coaxial with the axis.

Abstract: Provided herein, is a valve stem seal assembly having an elastomeric sealing element, a symmetrical retainer and a valve guide. The retainer has first portion, a second portion, a continuous stop formed between the first portion and the second portion, an inner surface and an outer surface. The valve guide has a top surface in contact with the elastomeric sealing element and a side surface in contact with the inner surface of the second portion of the retainer. The stop of the retainer projects radially inward and the retainer is symmetrical.

Abstract: A method for making a valve stem seal, comprising the steps of providing a metal retainer having a top portion and a body portion. The body portion having a first section and a second section. In a first state, the first section of the body portion is cylindrical and the second section of the body portion is cone shaped. Providing a hollow mold. Inserting the metal retainer into the outer mold piece, inserting the inner mold piece into the metal retainer, and then securing the inner and outer mold pieces to each other. Filling a cavity around the top portion of the metal retainer with an elastomeric compound. Removing the metal retainer and the formed rubber sealing element from the mold pieces, and pressing downward over the formed valve stem seal to compress the second section of the body portion radially inwardly.

Abstract: A system for lubricating a valve assembly of an engine. The system includes a valve bridge having a base portion is disposed on a guide rod. The guide rod is received within a hole defined in the base portion of the valve bridge to define a chamber and to receive lubricant in the chamber. The valve bridge includes an arm that is engaged with a valve stem. The valve bridge includes a passage in fluidly communicating with the chamber and an end of the arm. The system includes a valve disposed around the valve stem and valve stem guide. The valve seal includes a lip member that abuts an outer surface of the valve stem to control a flow of the lubricant from the passage to a gap defined between the valve stem and the valve stem guide.

Abstract: There is described a gasket for a valve of an internal combustion engine; the valve comprises a guide element defining a through seat, and a stem slidably moving in such a seat; the gasket comprises an elastically deformable seal element, having an annular configuration with respect to an axis and adapted to be fitted externally on said valve to cooperate with the stem and/or with the guide element; and a support member having an annular shape, fitted coaxially on at least part of the seal element; the support member is formed by a single component made entirely of plastic material.

Abstract: A valve stem seal utilizes a multi-piece construction to reduce the required manufactured tolerances and/or improve the stress handling capabilities. The valve stem seal can include a first member or can which can be assembled to a second member or spring seat. The can and/or spring seat can have a plurality of axially extending resilient fingers that are biased such that when assembled the fingers are bent against the bias due to the engagement between the can and the spring seat. The fingers on the spring seat allow the spring seat to bend or move relative to the can to accommodate the loading of a valve spring on the spring seat. The use of resilient fingers on the can and/or the spring seat reduces the manufacturing tolerances required for the valve stem seal.

Abstract: A cylinder head for an internal combustion engine has a body, a rigid center spacedly surrounded by the body, an annular outer valve seat on the body, and an annular inner valve seat on the center. A ring-shaped valve has an outer seat face and an inner seat face and is displaceable along an axis into a closed position bearing on the outer valve seat with the outer seat face and on the inner valve seat with the inner seat face. The inner valve seat or outer valve seat is slidable axially. A seal member set in a groove in the center or in the body engages the one slidable seat. At least one biasing member connected to the one slidable valve seat urges same toward the ring-shaped valve.

Abstract: The present disclosure relates to an engine valve device including: engine valves; valve guides configured to guide a reciprocating motion of the engine valves; and stem seals fitting on one end of each of the valve guides and circumferentially covering the engine valves, in which the engine valves have micro-machined oil ports on the surfaces surrounded by the valve guides or the stem seals.

Abstract: The present invention provides a vehicle valve stem seal having both durability and sliding properties at an extremely high level in addition to usual sealing performance. The present invention is a vehicle valve stem seal comprising an elastic member with a seal lip portion on an end of a valve stem guide, the seal lip portion slidably closely contacting with a valve stem of an engine, wherein the elastic member is formed of a composition containing a fluororubber and a fluororesin and has projecting portions at least on a surface of the seal lip portion, the projecting portions being substantially formed of the fluororesin contained in the composition, the fluororesin is a copolymer including a polymerization unit derived from ethylene and a polymerization unit derived from tetrafluoroethylene, and the fluororubber is a polymer including a polymerization unit derived from vinylidene fluoride.

Abstract: A valve stem seal assembly for an internal combustion engine includes an annular rigid case disposed around a valve guide and a valve stem. An annular elastomeric body is press fit within the annular rigid case and including a radially inwardly extending seal lip in sealing contact with the valve stem. The annular elastomeric body includes a first axial end facing the valve guide and a second axial end facing away from the valve guide. The annular rigid case includes a radially inwardly extending end wall opposing the second axial end of the annular elastomeric body and including a lip support extending axially from an inner portion of the radially inwardly extending end wall and opposing a radially inner surface of the radially inwardly extending seal lip.

Abstract: A valve stem seal assembly for an internal combustion engine includes an annular rigid case disposed around a valve guide and a valve stem. An annular elastomeric body is press fit within the annular rigid case and including a radially inwardly extending seal lip in sealing contact with the valve stem. The annular elastomeric body includes a first axial end facing the valve guide and a second axial end facing away from the valve guide. The annular rigid case includes a radially inwardly extending end wall opposing the second axial end of the annular elastomeric body and including a lip support extending axially from an inner portion of the radially inwardly extending end wall and opposing a radially inner surface of the radially inwardly extending seal lip.

Abstract: A valve stem seal for an internal combustion engine includes a seal body having a gas seal assembly spaced from an oil seal assembly in the axial direction of the valve stem seal. The gas seal assembly includes a first gas lip and a second gas lip disposed between the oil seal assembly and the first gas lip.

Abstract: A valve stem seal can include an elastomeric component having a first portion for having a sealed engagement with a valve stem, and a pressure relief lip engaging a valve guide. The pressure relief lip can have a sealing configuration and a venting configuration. The venting configuration can allow excess exhaust gases to vent from a combustion chamber. After the venting of excess exhaust gases, the pressure relief lip can close to the sealing configuration to prevent oil from entering the combustion chamber. The elastomeric body or the valve guide can include a pressure relief channel. The elastomeric body can also include a bumper engaging the valve guide. The pressure relief channel can be disposed in the bumper.

Abstract: A valve stem seal assembly in an internal combustion engine includes a cylinder head including an aperture therein in communication with a cylinder bore and a recessed pocket surrounding the aperture. A valve guide is received in the aperture and a valve stem is received in the valve guide. A valve seal support includes a radially outwardly extending flange disposed against a surface of the cylinder head external to the recessed pocket and a cylindrical body that extends into the recessed pocket. A valve spring contacts the flange and a resilient seal is secured to the rigid valve seal support and in sealing engagement with the valve stem.

Abstract: An exhaust valve stem seal assembly includes a casing and an elastomeric seal coupled to the casing. The elastomeric seal includes a stem seal portion for sealing against a stem of an exhaust valve. The stem seal portion includes a gas lip that extends radially inward. The casing includes a frustoconical shoulder extending radially inward toward a valve axis to a distal edge. The frustoconical shoulder defines an angle relative to a plane perpendicular to the valve axis between the range of 5° and 45°. The distal edge of the frustoconical shoulder is disposed behind and is substantially aligned with the gas lip along the valve axis.

Abstract: An internal combustion engine can comprise a crankcase, and a crankshaft rotatably supported in the crankcase. The crankshaft includes a drive sprocket attached thereto. A cam chain engages the drive sprocket, and a cam chain chamber houses at least a part of the drive sprocket and cam chain therein. The cam chain chamber is configured to pool oil in a lower portion thereof. A balancer is coupled to the crankshaft and is configured to be rotated by rotational power transmitted from the crankshaft. The balancer is also disposed within the cam chain chamber, and is configured to splash oil pooled in the cam chain chamber during the rotation thereof. The engine also comprises a wall portion disposed in the cam chain chamber. The wall portion is configured to cover an upper portion of the balancer, and is disposed adjacent to a periphery of the balancer.

Abstract: An engine includes a cylinder head at least partially defining a valve seat pocket. A valve seat is located proximate to the cylinder head to at least partially define the valve seat pocket. A pocket filler is located between the valve seat and the pocket insert such that the pocket filler occupies a substantial portion of the valve seat pocket. A pocket insert is attached to the cylinder head proximate to the valve seat pocket, such that the pocket insert lines at least a portion of the valve seat pocket.

Abstract: A valve assembly includes a tubular valve stem guide and a valve having a valve stem slidable in the bore of the valve stem guide. A lower valve stem seal has an annular body surrounding the valve stem and a skirt sealing with the valve stem guide. An upper valve stem seal has an annular body sealingly mounted on the valve stem and a skirt portion overlapping with the annular body of the lower valve stem seal during the reciprocating movement of the valve stem so that the upper and lower valve stem seals cooperate to prevent flow of oil to the bore of the valve stem guide. The valve stem is coated with a diamond-like carbon coating or a hard nitride coating, and the valve stem guide is of powered metal construction with approximately 1% by weight solid lubricant such as molybdenum disulfide or tungsten disulfide.

Abstract: A valve stem seal (10) for a combustion engine may comprise a cylindrical body (12) including a mounting portion (16) and a valve stem sealing portion (14) integrally formed with the mounting portion (16), and an o-ring (26) configured for sealing engagement with a valve stem reciprocating in a valve guide (40) of a valve of the combustion engine. The mounting portion (16) may define an opening (18) for receiving an upper end (43) of the valve guide (40) and may be configured for substantially fluid-tight engagement with the upper end (43) of the valve guide (40). The valve stem sealing portion (14) may include an annular groove (22) formed in an inner surface of the cylindrical body (12). The o-ring (26) may be received in the annular groove.

Abstract: The present invention provides a vehicle valve stem seal having both durability and sliding properties at an extremely high level in addition to usual sealing performance. The present invention is a vehicle valve stem seal comprising an elastic member with a seal lip portion on an end of a valve stem guide, the seal lip portion slidably closely contacting with a valve stem of an engine, wherein the elastic member is formed of a composition containing a fluororubber and a fluororesin and has projecting portions at least on a surface of the seal lip portion, the projecting portions being substantially formed of the fluororesin contained in the composition, the fluororesin is a copolymer including a polymerization unit derived from ethylene and a polymerization unit derived from tetrafluoroethylene, and the fluororubber is a polymer including a polymerization unit derived from vinylidene fluoride.

Abstract: A valve assembly includes a tubular valve stem guide and a valve having a valve stem slidable in the bore of the valve stem guide. A lower valve stem seal has an annular body surrounding the valve stem and a skirt sealing with the valve stem guide. An upper valve stem seal has an annular body sealingly mounted on the valve stem and a skirt portion overlapping with the annular body of the lower valve stem seal during the reciprocating movement of the valve stem so that the upper and lower valve stem seals cooperate to prevent flow of oil to the bore of the valve stem guide. The valve stem is coated with a diamond-like carbon coating or a hard nitride coating, and the valve stem guide is of powered metal construction with approximately 1% by weight solid lubricant such as molybdenum disulfide or tungsten disulfide.

Abstract: A valve stem seal for an internal combustion engine includes a seal body having a gas seal assembly spaced from an oil seal assembly in the axial direction of the valve stem seal. The gas seal assembly includes a first gas lip and a second gas lip disposed between the oil seal assembly and the first gas lip.

Abstract: A valve stem seal can include an elastomeric component having a first portion for having a sealed engagement with a valve stem, a second portion for engaging a valve guide, and a pressure relief lip extending from the second portion. The first portion can be configured to extend away from or within the second portion, and the second portion can have a channel formed therein. The pressure relief lip can have a sealing configuration and a venting configuration. The venting configuration can allow excess exhaust gases to vent from a combustion chamber. After the venting of excess exhaust gases, the pressure relief lip can close to the sealing configuration to prevent oil from entering the combustion chamber.

Abstract: A gasket for a valve in an internal combustion engine is provided with a support element having a tubular configuration according to an axis and coaxially mounted on the valve. An elastically deformable element is interposed between the support element and the valve. The support element includes a first portion elongated according to the above mentioned axis, and a second portion extending from the first portion in a direction transversal to the axis, at least partially housed in an annular seat of the elastically deformable element and having its radially outermost end connected to the first portion itself. The support element comprises a third portion extending from the radially innermost end of the second portion and folded on the second portion itself so as to generate, in the folding area, a rounded edge cooperating with the annular seat of the elastically deformable element.

Abstract: A gasket for a valve in an internal combustion engine is provided with a support element having a tubular configuration according to an axis and coaxially mounted on the valve. An elastically deformable element is interposed between the support element and the valve. The support element includes a first portion elongated according to the above mentioned axis, and a second portion extending from the first portion in a direction transversal to the axis, at least partially housed in an annular seat of the elastically deformable element and having its radially outermost end connected to the first portion itself. The support element comprises a third portion extending from the radially innermost end of the second portion and folded on the second portion itself so as to generate, in the folding area, a rounded edge cooperating with the annular seat of the elastically deformable element.

Abstract: A cylinder head assembly for an internal combustion engine including a cylinder head at least partially defining a flow path through the engine, including an intake port, an exhaust port, and a combustion chamber disposed between the intake port and the exhaust port. A valve is coupled to the cylinder head and movable relative to the cylinder head to selectively open the combustion chamber to one of the intake port and the exhaust port. A valve spring is positioned between the valve and the cylinder head and biases the valve to a closed position. A thermally insulating washer is positioned between the cylinder head and the valve spring.

Abstract: A valve stem seal can include an elastomeric component having a first portion for having a sealed engagement with a valve stem, and a pressure relief lip engaging a valve guide. The pressure relief lip can have a sealing configuration and a venting configuration. The venting configuration can allow excess exhaust gases to vent from a combustion chamber. After the venting of excess exhaust gases, the pressure relief lip can close to the sealing configuration to prevent oil from entering the combustion chamber. The elastomeric body or the valve guide can include a pressure relief channel. The elastomeric body can also include a bumper engaging the valve guide. The pressure relief channel can be disposed in the bumper.

Abstract: A valve device includes a valve housing body having a passage for fluid, a valve guide formed in the valve housing body, a valve stem sliding in the valve guide for opening and closing the valve, a hydraulic actuator for opening and closing a valve, and a hydraulic control valve for controlling the hydraulic actuator, in which a scraper is provided on an end of the passage side of the valve guide for scraping the deposits on the valve stem. Further, the hydraulic actuator and the hydraulic control valve are integrated with the valve housing body. Furthermore, the device is provided with a nozzle oriented toward the valve guide and having an orifice for jetting pressured oil for cooling.

Abstract: A valve stem seal having an annular valve body with an upper surface, a lower surface, and defining an aperture is disclosed. The valve body is positioned for selective sealing engagement with a valve stem. At least one orifice is disposed on an inner surface of the annular valve body between the annular valve body and the valve stem. The orifice controls the rate of oil flow between the annular valve body and the valve stem.

Abstract: A valve guide structure is provided which can suppress deterioration of a valve guide even if radial stress is applied on an upper portion of a stem of a valve. The valve guide structure is such that the stem 2 of the valve 1 is supported by an inner peripheral surface of the valve guide 16 to restrict moving directions of the valve 1. A recess 18 is formed on an inner peripheral surface of the valve guide 16 and extends downwardly from an upper end of the valve guide 16 along the stem 2 of the valve 1 so as to provide a clearance between the valve guide 16 and the stem 2 of the valve 1.

Abstract: A valve stem seal of an internal combustion engine is described wherein the valve stem seal includes an outer peripheral surface and an inner sealing surface. The inner sealing surface minimizes ingress of a liquid upwardly from an intake port area into an overhead engine area by having at least one sealing lip disposed on an upper portion of the inner sealing surface and extending away from the inner sealing surface. The sealing lip includes a generally square lower corner.

Abstract: One embodiment of the present invention provides a poppet valve offering an increased valve area, comprising an outer valve head having an outer valve port and an inner valve head having an inner valve port. The inner valve head is rotatable relative to the outer valve head to align the inner and outer valve ports, thereby increasing the effective valve area of the poppet valve. The path created by aligning the inner and outer valve ports can be designed to mix air flowing through the poppet valve. Another embodiment of the present invention provides a valve guide containing a poppet valve having a guide pin, wherein the guide pin rests within a groove in the valve guide. As the poppet valve moves through the valve guide, the groove controls movement of the guide pin and causes the poppet valve to rotate relative to the valve guide.

Abstract: The present invention provides a reduced emission, single cylinder engine incorporating an air flow arrangement for improving flow efficiency of the intake air drawn into the engine and the exhaust discharged from the engine.

Abstract: A valve stem seal assembly includes a changeable cap. The cap is made of a flexible material, such as plastic or the like. A sealing element with sealing lips for sealing the valve stem is integrally bonded to the cap. The cap includes one or more tabs with a gripping member that cooperates with a corresponding gripping member on the retainer to snap-fit the cap onto the retainer. The retainer can also be made of plastic material. Once fitted onto the retainer, the cap can be easily removed by constructively destroying the one or more tabs using a tool, such as a screwdriver. A cap with a new sealing element can then be snap-fit on the retainer. The changeable cap allows for replacement of the sealing element without replacing the retainer or other components of the valve stem seal assembly.

Abstract: A valve stem seal assembly includes a retainer and a sealing element disposed within the retainer. The retainer includes a step and one or more installation pads. The sealing element includes a first sealing lip for sealing a valve stem, and a second sealing lip for sealing a chamfer of a valve guide. The step of the retainer exerts a compression force, F, against the second sealing lip to seal the second sealing lip against the chamber of the valve guide. The one or more installation pads exerts a frictional force against the valve guide to prevent movement of said valve stem seal assembly. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: A two piece valve stem seal assembly including first and second generally cylindrical shells, one of which is partially axially nested or inserted within the other. The valve stem seal assembly also includes an engagement portion on the one of the shells for grippingly engaging the outer shell in order to substantially prevent or at least minimize the possibility of axial separation of the shells during subsequent assembly into an engine or other valve-containing device. The assembly may also optionally include a discontinuity on the one of the shells for axially retaining or axially interlocking the shells in order to substantially prevent or at least minimize such possibility of axial separation.