Glossary of Terms
V
A distributer component that changes the ignition timing the through the use of the manifold vacuum.
Valve --A part of a reciprocating engine that may be alternately opened or closed so as to control the induction of fuel/air mixtures or exhaust products from the combustion process.
Valve Cover --A cylinder head attachment containing lubricants that protects the valve’s mechanism from contaminants.
Valve Guide --A sleeve bearing possessing the capability of maintaining normal reciprocating motions while providing axial location of a valve.
Valve Keeper --Generally a two-part piece, the Valve Keeper secures the valve spring retainer to the valve stem in a cylinder head.
Valve Relief --The valve-shaped hole in a piston crown.
Valve Seat --In a cylinder head, the area in which a gas seal is formed by a valve head under spring pressure.
Valve Size --A valve head’s diameter.
Valve Spring Retainer (Collar) --A component containing the outer end of the valve spring(s) and connecting the valve stem to the spring.
Valve Spring Shim --A shim on a valve spring designed to adjust the pressure of the valve spring.
Valve Stem (Engine) --The shaft portion of an intake or exhaust valve in an engine.
Valve Stem (Wheel) --The part attached to a road wheel that admits/releases pressurizing air.
Vapor Lock --A condition in which abnormal fuel delivery exists as a result of the existence of vapors rather than liquid fuel in the fuel pump.
Velocity Stack (Air Horn/Trumpet) --A part generally found in the form of a cylindrical flare that is used to alter the dynamic coupling between carburetor and incoming air.
Vent --An opening allowing pressure equalization between inside and outside components by allowing a flow path for air and other gases.
Ventilation --Using the flow of air to cool a part, or the modification of a part to facilitate this process.
Venturi --A region of an air duct where reduced pressure is created to encourage the inflow of fuel through one or more jets.
Vibration Dampener --A device used to reduce the amplitude of vibrations of the part to which it is attached. Generally a Vibration Dampener is rubber-mounted and found in the form of a circular disk or pulley.
Visible --Possessing the capability of being seen.
Voltage Regulator --An electronic or electromechanical device used to regulate the charging of an alternator or generator.
