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 lift-valve assembly, comprising a lift valve within a housing that includes a pressure segment, a mounting segment, a port segment, and a seat segment. The lift-valve assembly may receive a lift valve, and the housing including a valve seat and a biasing spring in a selectively replaceable configuration suitable for use in a conventional internal combustion engine in place of the conventional individual components, actuated by a cam actuating system, and controlling fluid communication between a combustion chamber and both intake and exhaust systems.

The present invention addresses the problem of providing a sintered alloy valve guide capable of inhibiting valve adhesion even in a high-temperature environment. The problem can be solved by a sintered alloy valve guide impregnated with a lubricating oil including pores that are sealed on the valve guide outer circumferential surface. More particularly, the problem is solved by the sealing step of performing a sealing treatment of pores on the outer circumferential surface of a sintered body impregnated with a lubricating oil.

The present invention addresses the problem of providing a sintered alloy valve guide capable of inhibiting valve adhesion even in a high-temperature environment. The problem can be solved by a sintered alloy valve guide impregnated with a lubricating oil including pores that are sealed on the valve guide outer circumferential surface. More particularly, the problem is solved by the sealing step of performing a sealing treatment of pores on the outer circumferential surface of a sintered body impregnated with a lubricating oil.

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.

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.

An intake valve for an internal combustion engine is provided. The intake valve includes a valve stem with a hole in the valve stem forming an air channel there through that allows intake air to flow from an intake passage, through the air channel, into a cylinder of the internal combustion engine.

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 bounding the combustion chamber, and the component is connected to the plurality of cylinder head screws.

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 bounding the combustion chamber, and the component is connected to the plurality of cylinder head screws.

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.