Abstract: Inlet valves, with inlet cages, in inlet ports in a cylinder head, and outlet valves, with outlet cages, in outlet ports in the cylinder head, comprise mating combinations of elements which exhibit optimum and proper seating together. The bores and the cages have configurations which, upon elements of one of the combinations being substituted for elements of the other combination, will prevent the seatings from occurring. Consequently, only the correct elements, per combination, will join together and nest in the correct bore and, in this way, the seating of an inlet valve in an outlet bore, or vice versa, is avoided.

Abstract: An annulus, with outwardly projecting limbs, comprises the blank from which a valve retainer is formed. The retainer employs the limbs to latchingly engage an internal, recessed land in a cylinder, in order to support a valve within the cylinder, while a valve cage is thereafter set into the cylinder independently. The limbs of the blank are bent into a substantially normal disposition, relative to the annulus, albeit slightly splayed outwardly to insure a resiliently-effected latching thereof with the land, and free ends of the limbs have bights formed therein to present latching surfaces for engaging the land.

Abstract: In lieu of the customary valve assembly-holding setscrew, a ram, slidably engaged with the central bore of a valve housing cover, is adjustably held against the valve assembly by a plate-type ram cover. The latter cover is bolted to the valve housing cover. To insure that product gas can not escape from the valve housing, the ram has an annular shoulder thereon which prevents its removal outwardly from the housing cover; the ram can only be removed via the inner surface of the housing cover. Too, the ram has an O-ring seal thereon which is confined between the ram and the housing cover.