DEFINITION OF TERMS - CONTINUED
Valve Seat. The surface, normally curved, against which
the valve operating face comes to rest, to provide a seal
Volt. A unit of potential, potential difference, or electrical
against leakage of liquid gas, or vapor.
Valve Seat Insert. A metal ring inserted into the valve
Voltage Regulator. A device used in connection with a
seat; made of special metal that can withstand operating
generator to keep the voltage constant and to prevent it
from exceeding a predetermined maximum. (One of the
three units comprising a generator regulator.)
Valve Spring. The compression-type spring that closes
the valve when the valve-operating cam assumes a
Volumetric Efficiency. The ratio between the amount of
fuel-air mixture that actually enters an engine cylinder
and the amount that could enter under ideal conditions.
Valve Tappet. The part that rides on the valve operating
cam and transmits motion from the cam to the valve
Volute Springs. Helical coil springs made from flat steel
stem or push rod.
tapered both in width and thickness.
Valve Timing. Refers to the timing of valve closing and
V-Type Engine. An engine with two banks of cylinders
opening in relation to piston position in the cylinder.
set at an angle to each other in the shape of a V.
Valve Train. The train of moving parts to the valve that
Wander. To ramble or move without control from a fixed
causes valve movement.
course, as the front wheels of a vehicle.
Vapor Lock. A condition in the fuel system in which
Water Jacket. A jacket that surrounds cylinders and
gasoline has vaporized, as in the fuel line, so that fuel
cylinder head, through which coolant flows.
delivery to the carburetor is blocked or retarded.
Water Manifold. A manifold used to distribute coolant to
Velocity. The rate of motion or speed at any instant,
several points in the cylinder block or cylinder head.
usually measured in miles per hour or feet per second or
Water Pump. In the cooling system, the pump that
circulates coolant between the engine water jackets and
Venturi. In the carburetor, the restriction in the air horn
that produces the vacuum responsible for the movement
of fuel into the passing airstream.
Wheel Alinement. The mechanics of keeping all the
parts of the steering system in correct relation with each
Vibration. An unceasing back and forth movement over
the same path; often with reference to the rapid
succession of motions of parts of an elastic body.
Wheel Brake. A brake that operates at the wheel,
usually on a brakedrum attached to the wheel.
Vibration Damper. A weighted device that is attached to
the engine crankshaft at the end opposite its power
Wheel Cylinder. In hydraulic braking systems, the
output. Its purpose is to absorb engine vibration.
hydraulic cylinder that operates the brakeshoes when
hydraulic pressure is applied in the cylinder.
Viscosity. A measure of an oil's ability to flow at a
Winch. A mechanism actuating a drum upon which a
cable is cooled, so that when a rotating power is applied
Volatility. A measurement of the ease with which a liquid
to the drum, a powerful pull is produced.
turns to vapor.