Abstract: During engine operation, valve retainers and valve springs are constantly rubbing and impacting each other resulting in heat and wear. The purpose of this invention is to provide a surface coating onto the valve retainer to reduce the friction with the valve spring and thus improve durability. Specifically, this invention teaches a method to thermally apply coatings to the surface of the valve retainer. Although typically fabricated from steel, the usage of lighter weight titanium valve retainers is increasing for high performance, or racing engines. The reduced mass allows valves to move more readily and requires less spring pressure to operate, producing more power and a faster revving engine, however titanium is typically not as wear resistant as the steel it replaces. In one embodiment, a porous molybdenum or other oleophilic metal is applied to the surface of the valve retainer. In another embodiment, hard coatings of cermets, carbides, and super alloys are applied as coatings to valve retainers.

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: A spring retainer formed from a titanium alloy and comprising a cylinder and a brim formed integrally with the cylinder is disclosed. The brim has on a top thereof a slope formed such that a thickness of the brim decreases radially outwardly.

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 lightweight valve spring retainer with a wear resistant spring seat or seats is provided. The spring seats may be defined in part by a tungsten carbide layer.

Abstract: Disclosed herein is a variable spring force intake valve for use in two- or four-stroke internal combustion engines. The device comprises an intake valve body and a torsion spring attached to a gear and rod assembly. Manipulation, via manual or automated means, of the gear and rod assembly adjusts the tension/torsion force exerted by the torsion spring to preload the intake valve and/or to hold the intake valve in the closed position. Varying the tension/torsion force results in an ability to control the timing and the degree to which the ports of the intake valve are actually opened during the operating cycle of the piston, thereby providing a user with an opportunity to enhance the operation of a two- or four-stroke internal combustion engine.

Abstract: A valve moving apparatus of an internal combustion engine comprises an engine valve, a valve spring, a spring seat supporting an end of the valve spring and a cam driving the engine valve to open. A valve spring set load changing device in the valve moving apparatus comprises the spring seat including a base seat and a support seat movable relatively to the base seat, an actuator generating drive force in accordance with an operational condition of the engine and a manipulating mechanism transmitting the drive force to the support seat. The actuator and the manipulating mechanism are positioned outside of the spring seat. When the support seat is rotated by a predetermined amount by the drive force transmitted through the manipulating mechanism, the support seat moves also in direction of expansion and contraction of the valve spring to change set load of the valve spring.