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.

A valve assembly includes a valve body defining a bore therein, a valve stem, a spring retainer, a valve spring, and a detent mechanism. The valve stem extends through the bore in the valve body and is adjustable between an open position and a closed position. The spring retainer is spaced apart from the valve body along a longitudinal axis of the valve stem and fixed relative to the valve body. The spring retainer defines a bore through which the valve stem extends. The valve spring is captured between the valve body and the spring retainer and is configured to apply a biasing force to the valve stem that biases the valve stem toward the closed position. The detent mechanism is configured to increase the biasing force applied to the valve stem when the valve stem is in the closed position or within a predetermined distance of the closed position.

A valve assembly includes a valve body defining a bore therein, a valve stem, a spring retainer, a valve spring, and a detent mechanism. The valve stem extends through the bore in the valve body and is adjustable between an open position and a closed position. The spring retainer is spaced apart from the valve body along a longitudinal axis of the valve stem and fixed relative to the valve body. The spring retainer defines a bore through which the valve stem extends. The valve spring is captured between the valve body and the spring retainer and is configured to apply a biasing force to the valve stem that biases the valve stem toward the closed position. The detent mechanism is configured to increase the biasing force applied to the valve stem when the valve stem is in the closed position or within a predetermined distance of the closed position.

An internal combustion engine may include at least one cylinder and at least one hollow-heat valve. The at least one hollow-head valve may include a valve shaft and a valve head, and may be guided in a valve shaft guide. The engine may also include at least one valve seat ring on which the valve head sealingly lies when the at least one hollow-head valve is closed. The engine may additionally include a valve shaft seal with at least two seal lips and oil disposed between the valve shaft and the valve shaft guide. The at least one valve seat ring may be composed of a sintered metal including infiltrated copper. The valve shaft may include one of a chromium-containing coating and a boron carbide-containing coating.

An internal combustion engine may include at least one cylinder and at least one hollow-heat valve. The at least one hollow-head valve may include a valve shaft and a valve head, and may be guided in a valve shaft guide. The engine may also include at least one valve seat ring on which the valve head sealingly lies when the at least one hollow-head valve is closed. The engine may additionally include a valve shaft seal with at least two seal lips and oil disposed between the valve shaft and the valve shaft guide. The at least one valve seat ring may be composed of a sintered metal including infiltrated copper. The valve shaft may include one of a chromium-containing coating and a boron carbide-containing coating.

A valve guide for a coupling including a circular, longitudinally extending portion, including a substantially circular channel extending therethrough; a ring portion; a plurality of ports radially disposed around a centerline of the valve guide; and one of more collar supports disposed radially about the circular, longitudinally extending portion. The valve guide comprises a unitary one-piece component. A male portion for a coupling that includes a valve guide with integral assembly support and a method for assembling a coupling assembly are also disclosed.

A valve guide for a coupling including a circular, longitudinally extending portion, including a substantially circular channel extending therethrough; a ring portion; a plurality of ports radially disposed around a centerline of the valve guide; and one of more collar supports disposed radially about the circular, longitudinally extending portion. The valve guide comprises a unitary one-piece component. A male portion for a coupling that includes a valve guide with integral assembly support and a method for assembling a coupling assembly are also disclosed.

Internal combustion piston engine includes a cylinder head partly defining two ducts and a combustion chamber, and poppet valves movably arranged in the cylinder head between positions allowing or preventing flow between the combustion chamber and the ducts. The poppet valve has a stem, a valve head having a hollow interior space, a lower surface facing the combustion chamber, an upper surface including a portion adjacent the stem, and a peripheral edge section that extends from the upper surface of the valve head to the lower surface. The valve head is formed separate from but connected to the valve stem in a manner to enclose the hollow space, for example, by a circumferential welding seam. The peripheral edge section contains an arcuate contact surface that extends from the upper to lower surfaces of the valve head and without any sharp edges between upper and lower surfaces.

Internal combustion piston engine includes a cylinder head partly defining two ducts and a combustion chamber, and poppet valves movably arranged in the cylinder head between positions allowing or preventing flow between the combustion chamber and the ducts. The poppet valve has a stem, a valve head having a hollow interior space, a lower surface facing the combustion chamber, an upper surface including a portion adjacent the stem, and a peripheral edge section that extends from the upper surface of the valve head to the lower surface. The valve head is formed separate from but connected to the valve stem in a manner to enclose the hollow space, for example, by a circumferential welding seam. The peripheral edge section contains an arcuate contact surface that extends from the upper to lower surfaces of the valve head and without any sharp edges between upper and lower surfaces.

Various embodiments of the present disclosure are directed to liquid-cooled cylinder heads. In one example embodiment, a cylinder head is disclosed including a component which extends into a combustion chamber, an upper cooling jacked, a lower cooling jacket, a plurality of valves arranged around the component, a plurality of cylinder head screws, an oil deck, a fire deck, a plurality of valve guides, and a fixed connection. The fixed connection is arranged from each valve guide to the component, and is a ring having at least one support. The support and the ring extend at least from the oil deck to the fire deck thereby hounding the combustion chamber, and the component is connected to the plurality of cylinder head screws.