(gasoline and diesel), it is mounted on or in-line
ABDC--After bottom dead center.
with the air inlet housing. A filtering device in the
ABSOLUTE--The temperature measured using ab-
air cleaner removes dust and dirt particles from the
solute zero as a reference. Absolute zero is
-273.16C or -459.69F.
AIR CONDITIONING--A system designed to pro-
vide control over air temperature, movement, and
AIR-COOLED ENGINE--An engine cooled by air
buretor that supplies an additional amount of fuel,
circulating between the cylinders and around the
temporarily enriching the fuel-air mixture when the
cylinder heads, as opposed to the liquid-cooled
throttle is suddenly opened.
engine that is cooled by a liquid passing through
jackets surrounding the cylinders.
ACCELERATOR--Pedal and linkage used to control
AIR FILTER--A filter through which air passes, and
which removes dust and dirt particles from the air.
ACCUMULATOR--A device for storing liquid under
Air filters are placed in passages through which air
pressure. It usually consists of a chamber separated
must pass, as in the crankcase breather, air cleaner,
into a gas compartment and a liquid compartment
by a piston or diaphragm. An accumulator also
serves to smooth out pressure surges in a hydraulic
AIR-FUEL RATIO--The ratio between the volume
of air and the volume of fuel used to establish
the combustible mixture in the cylinder of an
AC--Alternating current or current that reverses its
direction at regular intervals.
AIR HORN--That part of the air passage in the
ACTUATOR--A device that converts fluid power into
carburetor of a gasoline engine that is on the
mechanical force and motion.
atmospheric side of the venturi. The choke valve is
ADDITIVE--A chemical compound or compounds
located in the air horn.
added to a fluid to change its properties.
ALLOY--A mixture of two or more metals.
AFFF (AQUEOUS FILM FORMING FOAM)--(A
fire fighting agent.) A liquid concentrate, which
converts mechanical energy into electrical energy
consists primarily of synthetic fluorocarbon
for charging the battery. Also known as an ac
AIR, COMPRESSED--Air at any pressure greater
current (ac) which must be changed (rectified) to
than atmospheric pressure.
direct current for use in an automotive electrical
AIR BLEED--A passage in the carburetor through
which air can seep or bleed into fuel moving
AMBIENT--Surrounding, such as ambient air, mean-
through a fuel passage.
ing surrounding air.
AIR BRAKES--Vehicle brakes actuated by air pres-
AMBIENT TEMPERATURE--The temperature of
the environment surrounding an object.
AIR CLEANER--A device through which air must
AMMETER--An electric meter that measures cur-
pass before entering the cylinders of an
rent, in amperes, in an electric circuit.
AMPERE--Unit of measurement of electric current
equipped with carburetors, it is mounted on the
flow. The current that will flow through a 1-ohm of
carburetor air horn. On engines with fuel injection