Abstract: A valve spring retainer for an internal combustion engine includes a body having a lower portion and an upper portion. The lower portion defines a radial flange and a first opening extending axially therethrough. The upper portion includes a first wall and a re-entrant lip. The first wall extends at least partially axially away from an outer perimeter edge of the radial flange. Together, the first wall and the radial flange define an open reservoir for receiving and retaining oil therein. The re-entrant lip extends from an outer end of the first wall at least partially radially inward toward a central axis of the first opening. The re-entrant lip extends over a portion of the reservoir defined by the first wall and the radial flange.

Abstract: A combustion engine includes an engine valve arranged to selectively open/close a combustion chamber of the engine, a cylinder head adjacent the combustion chamber, arranged to guide a valve stem of the engine valve, the engine valve being axially displaceable relative to the cylinder head between the combustion chamber closed position and the combustion chamber fully opened position, and a valve spring retainer connected to the valve stem. The valve spring retainer partly delimits a gas spring volume, which is in fluid communication with an adjacent gas volume via a port when the engine valve is in the combustion chamber closed position, and which is separated from the adjacent gas volume when the engine valve is in the combustion chamber fully open position, the port being open during at least 25% of the maximal stroke of the engine valve and being closed due to a displacement of the engine valve.

Abstract: A four-cycle internal combustion engine with a valve system having improved durability in the case of high revolution speed. The engine includes a cylinder head having a port, and a valve having a stem part continuous with a fillet part for opening or closing the port. A valve spring including inner and outer springs urges the valve in a direction to close the port. A valve guide holds the stem part slidably. A tubular spring guide supports an outer periphery part of an outer spring to prevent lateral deformation of the spring. A top end of the spring guide is positioned above a top end of a valve guide.

Abstract: In a valve gear mechanism of an internal combustion engine, there is provided a valve opening and closing a combustion chamber, a spring device which generates a force pressing the valve toward a valve seat, a drive mechanism driving the valve in an opening direction via an operating section capable of being in contact with and separated from the valve, and a separation inhibiting device which inhibits a separation between the operating section and the valve.

Abstract: A spring seat is formed of an outer spring seat 10k and an inner spring seat 10j formed in a stepped-down shape so as to be positioned lower than the outer spring seat 10k, and a valve spring is formed of an outer spring 37 and an inner spring 36 that is disposed coaxially inside the outer spring 37 and that is larger in spring length than the outer spring 37.

Abstract: A cylinder head 12 showing a guideway in which is located a rotatable valve 10, 12 comprising a fluid port operable to effect fluid communication between a cylinder and a fulid manifold in the guideway, whereby rotation of the valve effects alignment of the fluid port with the combustion chamber of a cylinder 4 to enable fluid flow between the valve 10, 12 and a cylinder 4, and wherein the cylinder head 2 further comprises a seal 22 which, in use, is movable from a first, non-sealing position in which the seal 22 is biased away from the valve 10, 12, and a second, sealing position in which the seal 22 is biased onto the valve by gaseous pressure from within a cylinder 4.

Abstract: The present invention relates generally to a method for providing an efficient and powerful engine for internal combustion four stroke engines using a single valve per cylinder as the intake and exhaust valve. Outside air emerging from an air filter is forcibly pumped into the engine head using a blower which then is drawn into the combustion chamber during the intake stroke. The timing for opening and closure of the single valve is controlled by the camshaft which is provided with a cam lobe profile capable of prolonging the valve timing thus enabling the valve to remain open for a longer duration to cater for evacuation of air in the exhaust stroke and the intake of air in the intake stroke thereby permitting the use of only one single valve per cylinder.

Abstract: A bias element which urges the valves in an internal combustion engine into their closed positions and includes a pair of arms and a bight portion connecting the two arms. Each arm has an aperture therein with at least one arm having an aperture that is keyhole-shaped, or having a first portion and second portion that is larger than the first portion. The arm which has the keyhole-shaped aperture is in operative biasing engagement with the end portion of a valve stem and the keyhole-shaped aperture engages the valve stem in that the first portion of the aperture lockingly engages the neck portion of the valve stem. The other arm is engages the shank portion of the valve stem.