Dictionary of Automotive Terms & Abbreviations

DICTIONARY OF AUTOMOTIVE TERMS

A

Abbreviation or symbol for absolute temperature, absorption coefficient, acceleration, adenine, ampere, amplitude, angular acceleration, area, attenuation coefficient, fine-structure constant, helium nucleus, Helmhotz free energy, magnetic vector potential, relative atomic mass, a stereoisomer of a sugar, substitution on a carbon atom next to one common to two condensed aromatic nuclei, substitution on the carbon atom next to the hetero-atom in ahetero-cyclic compound, and substitution on the carbon atom of a chain next to the functional group.

A-2 tire

A term used for tire sizes 16.00 and larger in nominal cross section. Also called earthmover or off-the-road tire.

AA

Abbreviation for "Automobile Association" a term used in Great Britain.

AAA

Acronym for "American Automobile Association" or "Alberta Automobile Association."

AABM

Acronym for "Association of American Battery Manufacturers, Inc."

AAE

Acronym for "Association of Automotive Employers" (Poland).

AAIA

Acronym for "Automotive Aftermarket Industry Association".

AALA

Acronym for "American Automobile Labelling Act."

AAM

Acronym for "Alliance of Automobile Manufacturers".

AAP

Acronym for "auxiliary acceleration pump".

A arm

See	A-arm

A-arm

A suspension linkage formed in the shape of an "A" or "V" found commonly on the front suspension. The sides of the two legs of the A-arm are connected to the chassis by rubber bushings and the peak of the A-arm is attached to the wheel assembly. In this way, the wheel can freely move up and down. Sometimes there is an upper A-arm, a lower A-arm, or both upper and lower A-arms. The British call it a "wishbone."

A-arm A suspension linkage formed in the shape of an "A" or "V" found commonly on the front suspension. The sides of the two legs of the A-arm are connected to the chassis by rubber bushings and the peak of the A-arm is attached to the wheel assembly. In this way, the wheel can freely move up and down. Sometimes there is an upper A-arm, a lower A-arm, or both upper and lower A-arms. The British call it a "wishbone."

Also see
double wishbone

A-arm suspension

See	double wishbone

AAS

Acronym for "air aspirator system."

ABC

[1] Acronym for "aerial bunched conductors"

[2] Acronym for "automatic beam control."

ABdc##

Acronym for after bottom dead center. A term used in timing the relation of the spark and the crankshaft.

Abel flashpoint apparatus

A device for testing the flash point of gasoline.

Abhesive

A substance which does not allow two materials from sticking together, e.g., Teflon^® on frying pans. Opposite of adhesive

Ability

See
climbing ability
cold cranking ability

Aboard

See	lighter aboard ship

Aboard ship

See	lighter aboard ship

A bone

Nickname for a Ford Model "A".

ABPV

Acronym for "air bypass valve."

Abradant

A grinding powder.

Also see
abrasive

Abrade

To grind or roughen up a surface by rubbing.

Abrasion

The action of removing some of the surface through rubbing friction.

Abrasion hardness

The ability of something (e.g., metal, ceramic) to resist abrasion.

Abrasive

A hard grit used for sanding or grinding. Usually a powder e.g., silicon carbide powder.

Also see
bonded abrasive coated abrasive non-woven abrasive

Abrasive blast cleaning

In order to clean steel or remove rust from iron or scale from metal, sand or some other powder substance is forced by air pressure through a nozzle. In this way the small particles of abrasive can penetrate the metal where sanding with sandpaper cannot. Also, very small craters are formed on the surface of the metal from the blasting action. When thoroughly cleaned the metal is ready for painting. Paint adheres better to these "craters and imperfections than to a perfectly smooth surface."

Abrasive cleaner

A cleaning paste with some hard grit. It is used to remove the grime and oils from a surface or from your hands.

Abrasive disc

A circular plate (often made of plastic with hard grit embedded into it) used for grinding or sanding.

Abrasive paper

Sandpaper (a paper upon which sand or hard grit has been glued) used for sanding or grinding.

ABS

Acronym for "anti-lock brakes. The acronym ABS comes from the German anti blockier system.

Also see
copolymer

Absolute

See manifold absolute pressure sensor and POA suction throttling valve

Absolute pressure

Pressure measured from a starting point of zero in perfect vacuum. When measured by the absolute pressure scale, atmospheric pressure is 14.7 psi or 29.92 inches of mercury (in-Hg).

Also see
manifold absolute pressure sensor

Absolute pressure sensor

See	manifold absolute pressure sensor barometric absolute pressure sensor

Absolute weight

The weight (or mass) of a body in a vacuum.

Absolute zero

The point at which there is a total absence of heat, minus 459.67°F (-273.15°C).

Absorbent

A substance with the property of assimilating another substance (e.g., sponge and water).

Absorber

Something which converts the dynamic energy of motion into potential energy (e.g., of a spring) such as in a shock absorber.

Also see
air shock absorber arc absorber adjustable shock absorbers damper	direct-acting shock absorber double-tube shock absorber friction shock absorber gas shock absorber	impact absorber lever-type shock absorber monotube shock absorber self-levelling shock absorber	shock absorber single-tube shock absorber. telescopic shock absorber UV absorber

Absorber rod

See	control rod

Absorber tower

See	shock absorber tower

Absorbing

See	energy absorbing steering column energy absorbing bumper

Absorbing bumper

See	energy absorbing bumper

Absorbing steering

See	energy absorbing steering column

Absorbing steering column

See	energy absorbing steering column

Absorption

The use of a chemical or filter to remove unwanted particles or characteristics from something.

Also see
acoustic absorption air absorption atmospheric absorption sound absorption

Absorption capacitor

A capacitor connected across a spark gap to reduce the discharge.

Absorption coefficient

[1] The volume of gas, measured at stp, dissolved by unit volume of a liquid under normal pressure (i.e., one atmosphere).

[2] The fraction of the energy which is absorbed.

Also see
acoustic absorption coefficient

Absorption dynamometer

A measuring device which absorbs and dissipates power, e.g., the ordinary rope brake and the Froude hydraulic brake.

Absorption factor

See	acoustic absorption factor

ABS override button

A button or switch which disengages the automatic anti-lock braking system so that the driver can operate the brakes himself.

ABS relay valve

An electrically controlled valve which modulates the air pressure in the ABS.

Abut

The action of two gear teeth making contact.

Abutment

[1] A part which stops the motion of another part from proceeding any farther.

[2] The contact made between opposing teeth of two gears.

Abutting edge

The edge or side of a panel which joins the edge or side of another panel.

ABV

Acronym for "air bypass valve."

A/C

[1] An abbreviation for air conditioning or air conditioner.

[2] An abbreviation for "across corners" which indicates the distance on a nut (for instance) from one corner to the opposite corner rather than the distance from one flat surface (A/F) to the opposite (which would be the size of wrench needed to install or remove the nut). The purpose of the A/C dimension is to know how large a hole might be needed to insert a recessed nut.

AC

[1] A vehicle brand of which the 1925-48 models are classic cars.

[2] Acronym for "alternating current."

[3] Acronym for "air conditioning" or "air conditioner."

[4] Symbol for actinium

[5] The transformation temperature on heating of the phase changes of iron or steel, subscripts indicating the designated change, e.g., Ac₁ is the eutectoid (723°C) and Ac₃ the ferrite/austenite phase boundary.

AC Ace

A vehicle brand of which the 1954-61 Ace models are milestone cars.

AC Aceca

(pronounced ah-SEEK-uh) A vehicle brand of which the 1955-61 Aceca models are milestone cars.

ACAP

Acronym for "Associação do comércio automovóvel de Portugal".

AC Buckland

A vehicle brand of which the 1949 Buckland Open Tourer is a milestone car.

Acc

Abbreviation for "accessories."

ACC

[1] Acronym for "Automatic Cruise Control."

[2] A term found on a cruise control switch which indicates the direction the switch needs to be moved to increase the speed (accelerate) of the vehicle.

ACCC

Acronym for "air conditioner clutch compressor" signal.

Accelerate

[1] To increase the speed of a vehicle. Opposite of decelerate.

[2] To speed up the chemical reaction or curing process of an adhesive. For example, you can speed up the drying time of an adhesive or sealer by increasing the temperature. Also, by adding a chemical curing agent, or accelerator, to a base compound.

Accelerating machine

See	accelerator

Accelerating-well ports

These ports prevent momentary leanness during the period that occurs between the opening of the air valve and the actual discharge of fuel from the secondary nozzles.

Acceleration

The rate of change of velocity or speed. Velocity is steady and is measured in distance per time (e.g., feet per second, miles per hour, kilometers per hour). Acceleration keeps increasing and is measured in velocity per time (e.g., feet (or meters) per second per second or feet (or meters) per second squared). It is a vector quantity and has both magnitude and direction.

Also see
angular acceleration lateral acceleration sluggish acceleration yaw acceleration

Acceleration enrichment

The action of increasing the fuel/air mixture during acceleration in order to improve the vehicle's speed and its smooth response.

Acceleration pump

See	auxiliary acceleration pump

Acceleration slip regulation

( ASR) The Bosch term for traction control.

Acceleration stress

The influence of acceleration (or deceleration) on certain physiological parameters of the human body. The degree of tolerance depends on the magnitude and duration of the acceleration as well as the direction of the force against his body.

Acceleration tolerance

The maximum acceleration force that a person can withstand before "blacking out" or otherwise losing control.

Accelerator

[1] In automobiles, this is the "gas pedal" which is attached by linkage to the throttle in the carburetor or to the fuel injection system. It regulates the amount of fuel which is sent to the engine. In motorcycles, the accelerator is located on the right-hand twist grip or an actuating lever.
[2] A chemical which is added to something to make a process happen more quickly. For example, a chemical may be added to paint to cause it to dry faster. The opposite is "retarder." A material added to an adhesive to speed up its cure or to chemically convert the whole mass to a solid. Accelerators differ from catalysts in that they are a part of the chemical reaction and lose their chemical identity as a result.
[3] Any substance increasing the speed of the vulcanization process of rubber.

Also see
depress the accelerator ease up on the accelerator step on the accelerator take foot off the accelerator

Accelerator interlock

A connection between the gas pedal and the automatic transmission.

Accelerator pedal

The accelerator, gas pedal, or throttle pedal.

Accelerator pump

A small cylinder and piston usually located inside the carburetor that sprays an extra amount of fuel into the engine during acceleration. It improves acceleration by giving more boost and reducing a momentary lag in power. It is actuated by depressing the pedal.

Accelerometer

An instrument which measures the amount of acceleration in a specific direction.

Also see
impact accelerometer vertical-gust recorder

Acceptable quality level

(AQL) A manufactured good that may not be perfect but does reach a level of shape, size, and performance, etc. that will make it work and last as long as the manufacturer expects.

Acceptance test

An examination of a part or its assembly to determine if it meets a prescribed standard.

Access

A way of reaching something that is usually hidden or covered.

Also see
access panel

Access Cab

A type of pickup truck (by Toyota) which as a second row of seating; but unlike a crew cab (which has four full size doors) it has a "half-door" that can be opened only after the main door is opened. The seating is usually a little more cramped than in a crew cab. Also called club Cab, extended Cab, king Cab, xtracab, supercab, or cab Plus

Access hole

An opening through which you can reach something. It is usually covered with a panel.

Accessible hermetic

Assembly of motor and compressor inside a single bolted housing unit.

Accessories

Items and packages of equipment which are beyond the standard equipment supplied in a new vehicle.

Accessory

See	accessories

Accessory gearbox

A transmission, driven remotely from the main engine, to which other items (e.g., generator, pumps) are mounted.

Accessory package

A set of features or appointments which may be ordered at extra cost on a new vehicle.

Access panel

The cover which conceals the engine on a mid-engine vehicle. Also called engine cover.

Also see
hood

Accident

See	car accident

Accident damage

The destruction caused to a vehicle's bodywork when it is involved in an accident.

Ac circuit

A circuit which passes only alternating current as opposed to direct current, e.g., it may have a capacitor in series, which blocks direct current.

Ac commutator motor

An ac motor which has a commutator as an essential part of its construction.

Also see
ac series motor compensated induction motor repulsion motor Schrage motor

Accord

A model of automobile manufactured by Honda
.
Click for books on
Honda Accord

Accumulator

[1] A storage battery for an electric car.

[2] A pressurized container for an automatic leveling suspension system.

[3] A part of the hydraulic system which is charged by the fluid pump, absorbs fluctuating fluid delivery, stores fluid at pressure, and can provide a rapid flow of fluid under pressure.

[4] A vessel that stores hydraulic fluid under pressure.

[5] A storage tank which receives liquid refrigerant from evaporator and prevents it from flowing into the suction line before vaporizing.

[6] A refrigerant storage device used on General Motors and Ford systems that receives vapor and liquid refrigerant from the evaporator. The accumulator, which contains "desiccant," performs a function similar to that of a receiver-drier it separates liquid from the vapor, retains the liquid and releases the vapor to the compressor. Always located on the low side of the system.

Also see
accumulator piston fuel accumulator hydraulic accumulator pressure accumulator

Accumulator battery

A storage battery (i.e., the main battery in your vehicle).

Accumulator box

A vessel usually made of plastic which contains the plates and electrolyte of an accumulator.

Accumulator drier

A device which is part of the air conditioning system. It is made up of a tank, filter, drying agent, and a vapor return tube. It is usually found on the evaporator outlet. It stores the excess refrigerant and removes the moisture from the refrigerant (thus the name "drier").

Also see
receiver drier

Accumulator grid

The lead grid which forms one of the plates of a lead-acid accumulator having pasted plates.

Accumulator piston

A unit found in the automatic transmission to assist the servo to apply the brake band quickly and smoothly.

Accumulator system

In an automatic transmission, it includes a hydraulic accumulator piston which is controlled by a valve.

Accumulator traction

See	battery traction

Accumulator valve

A device which operates the hydraulic accumulator piston in an automatic transmission.

Accumulator vehicle

See	battery traction

Ace

An American trucker's colloquial term for someone with a class "A" licence.

Also see
AC Ace

ACEA

Acronym for "Association des Constructeurs européens d_Automobiles" (i.e., European Automakers Association).

Aceca

See	AC Aceca

Acetylene

[1] A gas composed of two parts of carbon and two parts of hydrogen. When burned in an atmosphere of oxygen, it produces one of the highest flame temperatures obtainable for welding.

Also see
oxygen acetylene cutting

Acetylene bottle

See	acetylene cylinder

Acetylene cutting

See	oxygen acetylene cutting

Acetylene cylinder

A specially built container manufactured according to I.C.C. Standards. Used to store and ship acetylene. Also called acetylene tank or acetylene bottle

Acetylene hose

A flexible medium used to carry gases from regulators to the torch. It is made of fabric and rubber.

Acetylene regulator

An automatic valve used to reduce acetylene cylinder pressures to torch pressures and to keep the pressures constant.

Acetylene tank

acetylene cylinder.

AC generator

[1] An electromagnetic generator for producing alternating emf and delivering ac to an outside circuit.
[2] A generator produces direct current (dc##) while an alternator produces alternating current (AC). Because alternators were introduced to automobile electrical systems after generators had been in use for some time, some people referred to the new alternator as "AC generator."

Ache

See	head ache rack

Ache rack

See	head ache rack

Acid

Also see
battery acid chromic acid oxalic acid

Acid deposition

After acid compounds are sent into the atmosphere (e.g., through a smokestack), it returns to the surface mixed with the rain. acid rain.

Acid rain

[1] When the smoke created by factories and vehicle exhausts is taken by the wind and joined with rain clouds, the mixture is often acidic. As a result the rain that falls to the ground (and even on your car) may damage whatever it strikes.

[2] A form of wet deposition in which acid molecules or particles in the atmosphere are returned to the surface having been washed out by rain or snow as it falls. The unnatural acidity (pH 3-5.5) is caused mainly by the oxides of sulphur and nitrogen from the burning of coal and oil.

AC Ignition System

See	continuous AC Ignition System

Ackermann

See	Ackermann steering

Ackermann steering

[1] A double-pivoting steering system where the outer ends of the steering arms are bent slightly inward so that when the vehicle is making a turn, the inside wheel will turn more sharply than the outer wheel. This is done to compensate for the greater distance the outside wheel must travel. Notice 20 degrees on left wheel and 30 degrees on right wheel
[2] Arrangement whereby a line extended from the track-arms, when the wheels are set straight ahead, should meet on the chassis centerline at 2/3 of the wheelbase from the front, allowing the inner stub-axle to move through a greater angle than the outer.

Ackermann angle

The toe-out or toe-in of a vehicle with Ackermann steering when the wheels are positioned straight ahead.

Ackermann axle

In a vehicle with Ackermann steering (at the front of the vehicle), it is a non-rotating axle that is steerable and has two pivot points (one on each end of the axle) with vertical kingpins.

ACL BI-MET

Acronym for "air cleaner bi-metal sensor."

ACL DV

Acronym for "air cleaner duct and valve vacuum" motor.

Ac motor

An electric motor which operates from a single or polyphase alternating current supply.

Also see
capacitor motor induction motor synchronous motor

Acoustics

[1] The science of sound waves including production and propagation properties.

[2] The characteristics of the interior of a car which determine the quality of sound transmission inside.

Also see
architectural acoustics atmospheric acoustics

Acquisition fee

A charge for processing a vehicle lease and is probably not negotiable. On a shorter term lease, the acquisition fee can have a large impact on the cost of the lease.

Across corners

( A/C) The distance on a nut (for instance) from one corner to the opposite corner rather than the distance from one flat surface ( A/F) to the opposite (which would be the size of wrench needed to install or remove the nut). The purpose of the A/C dimension is to know how large a hole might be needed to insert a recessed nut.

Across flats

( A/F) The distance on a nut (for instance) from one flat surface to the opposite flat surface, i.e., this is the size of the wrench needed to install or remove the nut.

Also see
across corners.

ACR tubing

Tubing used in air conditioners and refrigerators. The ends are sealed to keep tubing clean and dry.

Acrylate

A polymer used to strengthen rubber (e.g., ethyl acrylate).

Acrylic

A term relating to a type of paint made by polymerizing acrylonitrile.

Acrylic fibers

Continuous long filaments or fibers from linear polymers.

Acrylic finish

A final coating of paint which uses acrylic paint, often where the pigment and an acrylic paint are mixed together.

Also see
two-pack paint.

Acrylic paint

A type of paint made by polymerizing acrylonitrile.

Acrylic resin

A thermoplastic synthetic polymer made by polymerizing an acrylic derivative such as acrylonitrile, acrylic acid, ethyl acrylate, and methacrylate. It is used for adhesives, protective coatings, and paint finishes.

ACS

[1] Abbreviation for active control system

[2] Abbreviation for attitude control system

[3] Abbreviation for air conditioning system .

AC Shelby Cobra

A vehicle brand of which the 1962-67 Shelby Cobra models are milestone cars.

ACT

[1] Acronym for "air charge temperature."

[2] Acronym for active control technology.

Also see
active control system

Act

See	Motor Vehicle Safety Act

Acting

See	double-acting dual-acting single-acting

Action
Also see
caster action
oscillating action
parallel action locking pliers
reciprocating action

Action brakes

See	servo action brakes

Action locking

See	parallel action locking pliers

Action locking pliers

See	parallel action locking pliers

Activate

To change an adhesive film from a dry or inactive state to a useful, sticky state.

Activated

See	cable activated

Activated carbon canister

An automotive filter in which activated carbon has been placed so that gas tank fuel vapors, which have accumulated when the vehicle is not running, are trapped in the filter. When the engine is running, hot air is forced into the filter and push out the vapors into the engine. In this way, pollution is reduced and conservation of the fuel is maintained. Also called activated charcoal trap or charcoal canister.

Activated charcoal

Charcoal treated with acid to increase its adsorptive power

Also see
activated carbon charcoal

Activated charcoal trap

See	activated carbon canister

Activator

A substance which is used to speed up the process of curing a tire. Also called activating agent.

Active braking time

The length of time (excluding the driver's reaction time) a vehicle takes to come to a complete stop after the brakes are applied.

Active material

In a storage battery, the brown peroxide of lead of the positive plates and the gray metallic lead of the negative plates upon which the sulphuric acid acts.

Active noise control system

See	anti-noise system

Active safety

The opposite of passive safety. Passive safety involves seat belts, airbags, bumpers, etc. so that in the event of an accident the passengers are protected. Active safety involves factors which will assist the driver in avoiding an accident. They include brakes, steering, handling response, acceleration, etc.

Active suspension

While conventional suspension uses springs and shock absorbers to isolate the vehicle from the bouncing movement of the wheels when it contacts rough roads, active suspension uses power actuators which are controlled by a computer. These actuators place the wheels of the vehicle in the best position to accommodate rough roads as well as compensate for different load levels.

Activities

See	Kaizen Activities

Activity factor

See	blade activity factor

Ac transformer

An electromagnetic device which alters the voltage and current of an ac supply in inverse ratio to one another. It has no moving parts and is very efficient.

ACTS

Acronym for "air charge temperature sensor."

Actual cash value

(ACV) The amount of money a dealer has invested in the purchase of a used vehicle and any additional costs to repair the unit in order to get it ready for resale.

Actuate

The action of bringing something into operation.

Actuating lever

A triggering device used to bring something into operation.

Actuating switch

A triggering device used to bring something into operation.

Actuation

See	variable valve actuation

Actuator

[1] A device which controls or operates another device.

[2] A regulating valve which converts a form of energy into mechanical motion to open or close the valve seats

Also see
hydraulic actuators

Actuator arm

A linkage connecting the diaphragm to the contact breaker platform in an advance mechanism of a distributor. Also called diaphragm link..

Acura

A vehicle brand from the Honda manufacturers
.
Click for books on Acura

ACV

[1] Acronym for "actual cash value."

[2] Acronym for "air control valve"

[3] Acronym for air cushion vehicle (i.e., hovercraft).

Ad

See	classified ad

Adapter

[1] A device used to connect two different types or sizes of electrical terminals

[2] A connector which links two items usually of dissimilar structure or size. (Also spelled "adaptor")

Also see
bit adapter bit adapter caliper mounting bracket carburetor adapter engine adapter increasing adapter ratchet adapter reducing adapter transmission adapter wheel adapter.

Adaptor carburetor

A device attached to a gasoline carburetor which permits an internal combustion engine to run either on gas or liquefied petroleum gas (LP gas).

Adapter plate

A plate which is placed between two different parts in order to link them. (Also spelled "adaptor plate")

Also see
transfer plate

Additive

A substance (liquid or powder) which is added to gasoline or oil and is intended to improve the characteristics of the original product.

Also see
anti-knock additive fuel additive oil additive

ADEFA

Acronym for "Asociacion de Fabricas de Automotores" (Argentina).

ADF

Abbreviation for automatic direction finding.

Adhere

To stick or be glued to something.

Adherend

[1] Each surface that is to stick to another

[2] A material which is stuck together by an adhesive.

Adhesion

[1] The force which causes two surfaces to stick together

[2] The sticking together of surfaces in contact with each other

[3] The bonding of materials with adhesives (glues, cements, binders, etc), in which the intermolecular forces between adhesive and adherend provide the bonds.

[4] The sticking together of two metals as a result of compressing them together

[5] The sticking together of two dissimilar metals because of electrical transference of electrons.

Also see
cold welding

[6] The ability of paint, primer, or glue to stick to the surface to which it is applied.

[7] The ability of a tire to grip the surface of the road.

[8] Mutual forces between two magnetic bodies linked by magnetic flux, or between two charged non-conducting bodies which keeps them in contact

[9] Intermolecular forces which hold matter together, particularly closely contiguous surfaces of neighboring media, e.g., liquid in contact with a solid.

Also see
intercoat adhesion failure limits of adhesion

Adhesion failure

See	intercoat adhesion failure

Adhesive

[1] A substance (like glue) that is used to join two substances. An adhesive must bond both mating surfaces through specific adhesion (molecular attraction), through mechanical anchoring (by flowing into holes in porous surfaces), or through fusion (partial solution of both surfaces in the adhesive or its solvent vehicle). Various descriptive adjectives are used with the term adhesive to indicate types, such as

a. physical form: Liquid adhesive, film adhesive, etc.
b. composition: Resin adhesive, rubber adhesive, silicone based, mastic, etc.
c. end use: Metal-to-metal adhesive, plastic adhesive, rubber adhesive
d. application: Sprayable adhesive, hot melt adhesive, etc.

[2] Agent for joining materials by adhesion, usually polymeric material. May be based on thermoplastic resin (e.g., polystyrene cement) or thermoset (e.g., epoxy resin). Viscosity is important for gap filling (high, as in epoxies) or surface penetration (low, as in cyano-acrylates). Also called binder, cement, or glue

Also see
automotive adhesive air drying adhesives impact adhesive separate-application adhesive

Adhesive film

A thin layer of dried adhesive.

Adhesive tape

A tape with a sticky substance on one side. It usually comes in a roll of various widths. Sometimes used to insulate electrical wires (e.g., electrical tape) or to wrap a larger object (e.g., duct tape). Often the non-sticky side is shiny (but not always) to distinguish it from the sticky side.

Adhesive weight

Lead wheel weights which have a sticky backing. It comes in strips and is applied to a wheel rim to balance a wheel. Also called tape weight..

Adiabatic

A property of being able to maintain heat evenly. It does not gain any heat or lose it.

Also see
thermal efficiency

Adiabatic change

Without changing the temperature of an enclosure or its surroundings, there is a change in the volume and pressure of the contents of the enclosure.

Adiabatic compression

Compressing refrigerant gas without removing or adding heat.

Adiabatic efficiency

The ratio of that work required to compress a gas adiabatically to the work actually done by the compressor piston or impeller.

Adiabatic engine

An engine which is very efficient in transferring combustion heat to those parts of the engine which are being cooled by the flow of anti-freeze coolant -- thus maintaining an even temperature of the engine. In this way the engine is warm enough for efficient running and it does not overheat.

Adjust

The action of putting something into its proper alignment or position. It may involve one component (e.g., He adjusted the gasket to fit properly.) or a series of components (e.g., He adjusted the poor idle -- might mean he set the ignition timing, adjusted the carburetor screws, changed the choke setting, cleaned or replaced the spark plugs, etc.)

Also see
tweak

Adjustable

A characteristic of something that can be changed, removed, or give different properties.

Also see
height adjustable steering column

Adjustable bottom bracket

[1] A component of a bicycle through which the crank fits. It has two bearing cups on either side. One cup is fixed in place while the other is removable or adjustable.

[2] This is the older type of bottom bracket before sealed cartridge bottom brackets became prevalent. The adjustable bottom bracket requires fixed and adjustable cup tools to properly tension the bearings. The bearings are not sealed, but they're easily accessible for cleaning and lubrication.

Also see
bottom bracket

Adjustable cup

The left-hand cup in a bottom bracket of a bicycle, used in adjusting the bottom bracket bearings and removed during bottom bracket overhaul. The other cup is the fixed cup.

Adjustable off-idle air bleed

Some emissions-era Rochester carburetors have a separate air passage to bleed air past an adjustment screw into the idle system. this screw is preset by the factory to produce precise off-idle air/fuel mixture ratios to meet emission-control requirements.

Adjustable part throttle

(APT) a supplementary circuit on some carburetors that can be adjusted to control part-throttle mixtures more accurately than a fixed orifice. The APT detours around the main jet, going directly from the float bowl to the discharge nozzle feed well.

Adjustable-pitch propeller

See	propeller

Adjustable-port proportioning valve

Air and fuel valves for oil or gas burners, motor operated in unison by automatic temperature-control equipment.

Adjustable rocker arm

A type of rocker arm with an adjusting nut that can be tightened or loosened to adjust valve lash.

Adjustable shock

See	adjustable shocks

Adjustable shock absorbers

Shocks with adjustable jounce and rebound characteristics can be stiffened to compensate for wear or to fine tune a suspension for a particular application such as rough roads, heavy loads, or racing.

Adjustable shocks

Shock absorbers which can compensate for varying needs of stiffness or softness. Manual types (especially on motorcycles) require that you physically make the adjustment from one level to another. Automatic types are controlled by a computer as it senses particular changes in road condition.

Adjustable spanner

British term for adjustable wrench.

Adjustable steering

See	height adjustable steering column

Adjustable steering column

See	height adjustable steering column

Adjustable variable exhaust port

A device used on two-stroke engines which automatically alters or varies the exhaust port size.

Adjustable wrench

A crescent wrench or pipe wrench. A tool which has a fixed jaw and a movable jaw which is controlled by a spiral gear. It is used to install or remove bolts and nuts of various sizes. The wrench itself comes in a variety of lengths and jaw sizes. A crescent wrench has smooth jaws while a pipe wrench has serrated jaws. British term is "adjustable spanner."

Adjusted

See	factory adjusted

Adjuster

A device for moving something into the correct position or into a different position such as a seat adjuster.

Also see
automatic adjuster automatic wear adjuster brake adjuster horizontal adjuster jet adjuster ride-height adjuster

Adjuster cam

A device for moving the shoes on drum brakes closer to the drum itself so that there is less travel when the brakes are applied.

Adjusting

Also see
electrode adjusting tool headlight adjusting screw self-adjusting

Adjusting gage

See	adjusting gauge

Adjusting gauge

A tool used to determine the small distance between two parts so that they can be brought within specifications.

Adjusting screw

A small screw usually found on carburetors, brakes, or headlights which change the way something operates, such as increasing or decreasing the amount of fuel entering the engine; or changing the idle speed; or tightening up the brakes; or changing the setting on rocker arms; or the level of the headlights.

Also see
headlight adjusting screw tappet adjusting screw valve adjusting screw

Adjusting shim

A thin washer or plate which reduces or increases the clearance between two components (depending upon where they are placed). While some valves are adjusted by screws on the rocker arm, others are set by inserting a shim to make the same adjustment.

Adjusting sleeve

A small threaded cylinder on the end of the tie rod which shortens or lengthens the rod to make changes in the toe-in and toe-out.

Adjusting spanner

See	brake adjusting spanner

Adjusting tool

Also see
brake adjusting tool electrode adjusting tool

Adjusting wrench

See	brake adjusting wrench

Adjustment

[1] Changing or modifying the position or alignment of two components.

[2] The distance of travel that a component has.

Also see
fore and aft adjustment idle mixture adjustment screw idle speed adjustment

Adjustment screw

See	idle mixture adjustment screw

Adler

The brand name of a vehicle. With required application the 1925-48 models are classic cars.

Admission

The point in the working cycles of a steam or internal-combustion engine at which the intake valve allows entry of the working fluid into the cylinder.

A-dos

See	dos-a-dos

A-drier

See	a-dryer

ADS

Abbreviation for air data system.

A-dryer

A paint dryer which has the heating elements below the paint drying line.

ADS

Acronym for "Association of Diesel Specialists."

Adsorbent

Substance with the property to hold molecules of fluids without causing a chemical or physical change.

Adsorption

The bonding that takes place when a gas or vapor comes into contact with a solid. The opposite is desorption.

Adsorption canister

See	activated carbon canister

Advance

[1] The act of changing the ignition timing so that the spark occurs earlier in the cycle. The opposite is retard.

[2] It may refer to the device which makes this adjustment.

[3] The length of railway track beyond a signal which is covered by that signal

Also see
angle of advance automatic advance centrifugal advance electronic spark advance ignition advance mechanical advance ported vacuum advance spark advance speed control vacuum advance vacuum advance

Advance capsule

See	vacuum advance

Advance curve

As the speed of the engine increases the ignition advance also increases. On paper, a pattern is drawn as a curve to represent this relationship.

Advanced

[1] A condition in which something occurs early.

[2] A product which is on the cutting edge of technology and shows the latest in new ideas and concepts.

Advanced rim taper

A rim where both bead seats are tapered 5°.

Advance mechanism

See	vacuum advance mechanism

Advance spring

A small spring which pulls the advance weight back.

See	picture in advance weight

Advance unit

See	vacuum advance unit

Advance weight

One of two small weights located in a centrifugal advance assembly.

Advertising

A colloquial term for a police car with its emergency lights flashing.

AEA

Acronym for "Automotive Electric Association" or "Automotive Electronic Association."

AERA

Acronym for "Automotive Engine Rebuilders Association."

Aeration

A foaming of a liquid because air has been introduced into the fluid. When it occurs in certain liquids, it decreases the efficiency of the liquid.

Aerial

British term for antenna.

Also see
retractable aerial whip aerial

Aerial bunched conductors

(ABC) Method of power transmission where the three conductors are twisted into a thicker insulated cable. More expensive but better at surviving blizzard conditions than normal separate conductors.

AERO

Abbreviation for "Air Education and Recreation Organization" in the UK.

Aero-

Prefix from Greek aer (αερ) indicating "air."

Aerobar

An extension to bicycle handlebars which project forward to give the rider an alternate riding position and a lower, more aerodynamic position. His elbows rest in the pads while he grabs the upright ends of the bars. Aerobars were popularized by triathletes and Greg Le_Mond.

Aerobars

Sometimes referred to as Tri bars. Aerobars popularized by triathletes and Greg Le_Mond, are attached to handlebars in order to provide a rider with a lower, more aerodynamic position.

Aerobic sealer

A substance (such as room temperature vulcanizing ( RTV), a common silicone rubber sealing compound) that requires the presence of oxygen to hold parts together.

Also see
anaerobic sealer

Aerodynamic

The efficient flow of air around an object.

Aerodynamic balance

A balance, usually but not necessarily in a wind tunnel, designed for measuring aerodynamic forces or moments.

Aerodynamic center

The point about which the pitching moment coefficient is constant for a range of airfoil incidence.

Aerodynamic drag

The resistance of the air to forward movement, sometimes called "air resistance." This is a factor of the shape of the vehicle (drag coefficient and frontal area), the objects which stick out (i.e., mirrors, mufflers, bumpers), the amount of turbulence at the rear of the vehicle, the nature of the vehicle's skin surface, and the amount of air going through the vehicle for cooling and ventilation. The faster you go, the greater the air friction (air friction = velocity x velocity). The faster you go, the greater the amount of power needed to overcome this drag (power = velocity x velocity x velocity).

Aerodynamic heating

The heating of a vehicle passing through the atmosphere, caused by friction and compression of air (or other gas).

Aerodynamics

The study of the flow of air as it passes over and around a moving object as well as the forces which the air makes on the object. An airplane, for instance, needs positive lift to get it airborne and negative lift to help it land. Thus the shape of a land vehicle (car, bicycle, etc.) either promotes positive or negative lift. Race cars may use spoilers and wings (air foils) to control lift. In vehicle design, the airflow is monitored in a wind tunnel. As well, aerodynamics also studies the most efficient shapes for increased speed and fuel economy.

Aerodynamic stance

In order to create less drag, the vehicle is lowered closer to the ground. This improves the flow of air over the vehicle. A better aerodynamic stance helps the vehicle to go faster when it is going in a straight line as well as give better fuel economy. Also, when a vehicle sits lower to the ground, it has a low center of gravity which makes it more stable when going through turns and enables the driver to maintain a higher speed.

Aero-engine

The power unit of a small aircraft.

Also see
ducted fan gas turbine ramjet turbojet turboprop turboramjet turborocket variable cycle engine

Aerofoil

British spelling for airfoil a body or body panel shaped like a wing so as to produce an aerodynamic reaction (lift) normal to its direction of motion, for a small resistance (drag), in that plane; e.g., a wing, plane, aileron, tailplane, rudder, or elevator.

Also see
air foil

Aeroplane

British spelling for airplane.

Also see
aircraft airplane

Aero system

A roof rack designed for cars without external rain gutters. The rack is held on by clips that extend down into the door.

Aether

See	ether

AEV

Acronym for automatic expansion valve.

A/F

[1] Abbreviation for "across flats" which is the distance on a nut (for instance) from one flat surface to the opposite flat surface, i.e., this is the size of the wrench needed to install or remove the nut.

Also see
across corners

[2] Abbreviation for "air/fuel."

See	air-fuel ratio

[3] Abbreviation for "automatic focusing"

[4] Abbreviation for "audio-frequency."

AFB

Acronym for "Aluminum four-barrel," as in Carter AFB carburetor.

AFC

[1] Acronym for "air flow controlled"

[2] Abbreviation for "automatic frequency control."

AFCS

Abbreviation for automatic flight control system.

AFM

Abbreviation for audio-frequency modulation.

A-frame

A chassis frame which is shaped like the letter "A" where the crossbar is often the axle. It is usually found as the frame of a trailer.

Also see
shear-legs

A-frame barricade

A traffic marker indicating that the road is not usable.

A/F ratio

See	air-fuel ratio

Aft

The back of a vessel.

Also see
fore and aft adjustment

Aft adjustment

See	fore and aft adjustment

Aft cg limit

See	cg limits

After bottom dead center

(ABdc##) The position of the piston as it starts its way up.

Afterburner

A device for burning excess carbon wastes produced by the engine so that air pollution is reduced.

Also see
reheat

Afterburning

In an internal-combustion engine, persistence of the combustion process beyond the period proper to the working cycle, i.e., into the expansion period.

Afterburst

Delayed further collapse of underground workings after a rockburst.

Aftercooler

[1] A device in a diesel engine which removes the relatively warm air which enters the engine.

[2] Chamber in which heat generated during compression of air is removed, allowing cool air to be piped underground.

Afterglow

[1] The period during which the glow plugs of a diesel engine continue to operate after the engine is started.

[2] The glow of a gaseous medium immediately after the cessation of electric current or downstream of an electric discharge.

Also see
persistence

Aftermarket

All products and services used in the repair and maintenance of vehicles after the vehicle has been sold.

Aftermarket equipment

Accessories and replacement parts added to a vehicle after it has been sold.

Aftermarket overdrive

An overdrive device which is not original equipment, but has been added after it has been sold.

Aftermarket part

Goods not for use as original equipment in the production of light-duty vehicles or heavy-duty vehicles, i.e., products and services used in the repair and maintenance of these vehicles.

Aftermarket rustproofing

Although most vehicles come from the manufacturer with some rustproofing, there is no guarantee that every part of the exposed chassis and frame will be protected from the elements and the possibility of rust. Therefore rustproofing is applied by the owner of the vehicle to reduce the possibility of rust. If this rustproofing is not done when the vehicle is new, it might seal in the rust and create a greater problem.

After-start enrichment

When an engine is first started, it needs a little richer fuel-air mixture (i.e., more fuel, less air). In a carbureted engine, this is accomplished by the choke (which restricts the amount of air). In a fuel injected engine, the after-start enrichment device increases the amount of fuel. As the engine warms up, the device gradually reduces the amount of enrichment. Some devices just reduce the amount gradually over time without sensing the temperature of the engine.

After top dead center

(ATdc##) A term used in timing the relation of the spark and the crankshaft. The position of the piston as it starts its way down.

AG

Acronym for "air-guard."

AGC

Abbreviation for automatic gain control.

Agency

See	driver and Vehicle Licensing Agency energy Protection Agency

Agent

An intermediary with legal authority to operate on behalf of the manufacturer.

Also see
activating agent addition agent aggressive agent air-entraining agent anti-knock agent bonding agent degreasing agent oxidizing agent reducing agent release agent rustproofing agent softening agent

Agent fee

Although you can register your vehicle and obtain your licence from a government office, some states and provinces permit an agent to perform that same service and allow the agent to collect an extra fee for the service. In this way the lineup at the government office is reduced.

Aggressive

A French expression to indicate the reinforced front, rear, and side safety structures of a vehicle. If the strengthened structure causes more than normal damage to another vehicle, a pedestrian, or the occupants of the vehicle, then that structure is aggressive.

Aging

[1] The cracking, checking, or general deterioration produced by exposure of an adhesive, coating or sealer to the weather or some other given set of conditions for a length of time

[2] The deterioration of rubber properties by oxidation over a period of time.

[3] A change in the properties of some metals after heat treatment or cold working (i.e., hammering or bending when metal is cold).

[4] The final stage of precipitation hardening, producing an increase in strength and hardness in metal alloys, due to precipitation of second phase particles from supersaturated solid solution over a period of days at room temperature, or several hours at an elevated temperature (called artificial aging)

[5] Loss of strength in the cladding or the pressure vessel in a nuclear reactor due to irradiation. Artificial aging would be the simulation of such processes by increasing the rate of irradiation to obtain information more rapidly

[6] Change in the properties of a substance with time. A change in the magnetic properties of iron, e.g., increase of hysteresis loss of sheet-steel laminations; also the process whereby the subpermanent magnetism can be removed in the manufacture of permanent magnets

Also see
artificial aging tire aging

Agitation cup

A type of spray gun paint container which has an agitator.

Agitator

[1] A device used to cause motion in confined fluid

[2] A device for mixing paint by shaking the container.

[3] A tank, usually cylindrical, which has a mixing device such as a propeller or airlift pump near the bottom. Finely ground mineral slurries (the aqueous component perhaps being a leaching solution) are exposed to appropriate chemicals for purpose of extraction of gold, uranium, or other valuable constituents. Types include pachuca tank or Brown agitator.

AGO

Abbreviation for automotive gas oil.

AGR

Abbreviation for advanced gas-cooled reactor.

Agreement

See	Free Trade Agreement of the Americas General Agreement on Tariffs and Trade North American Free Trade Agreement

Agreement of the Americas

See	Free Trade Agreement of the Americas

Agreement on Tariffs

See	General Agreement on Tariffs and Trade

Agreement on Tariffs and Trade

See	General Agreement on Tariffs and Trade

Aground

See	hard aground

AGS

Abbreviation for aircraft general standard.

AGVS

Acronym for "Automated Guided Vehicle System."

A.h.

Abbreviation for ampere-hour.

AHAI

Acronym for "Association of the Hungarian Automotive Industry".

AHAP

Acronym for "As High As Possible."

AHARA

Acronym for "As High As Reasonably Achievable."

Ahm

Abbreviation for ampere-hour meter.

Ahoogah

The sound of a particular kind of horn.

AHRA

Acronym for "American Hot Rod Association."

AH Rim

A wheel rim which is able to run even when the tire is flat and provides safety in case of a puncture.

AIAA

Abbreviation for American Institute of Aeronautics and Astronautics.

AIADA

Acronym for "American International Automobile Dealers Association".

AIAM

Acronym for "Association of International Automobile Manufacturers".

AIA-SAP

Acronym for "Automotive Industry Association" (Czech Republic).

AIA-ZAP

Acronym for "Automotive Industry Association" (Slovakia).

AIMA

Acronym for "Associação dos Industriais de Montagem de Automóveis" (Portugal).

Aimer

A tool for aiming headlights.

Aiming

Adjusting the direction of the headlight beams to shine without blinding oncoming traffic and yet providing the maximum illumination whether in low beam or high beam.

Air

[1] Abbreviation for "air conditioner."

[2] A bicycling or motorcycling term describing the space or gap between the tires and the ground when the bike takes a jump. Both tires must be off the ground before it can be called "air" as in the expression, "I really caught air on that last jump."

[3] A gas containing approximately 80% nitrogen, 20% oxygen, and a small portion of other gases. One of the essential factors in a combustion engine (fuel, air, proper proportion of mixture, compression, timing, and spark).

Also see
ambient air bath air charge air cold air driver air bag electric air control valve electric air switching valve	external mix air cap fuel air mixture fuel air ratio heater air pipe idle air bleed screw idle air jet internal mix air cap	L-jetronic air flow meter lateral air passage low-profile air cleaner modular air strut oil bath air cleaner paper air cleaner passenger-side air bag	proper proportion of air and fuel pulse air principle pulse air system ram air secondary air

AIR

An acronym for "Air Injection Reactor" system of reducing objectionable exhaust emissions.

Also see
air injection

Air and fuel

See	proper proportion of air and fuel

Air aspirator system

(AAS) A passive air injection system that uses a one-way valve instead of an air pump to introduce extra air into the exhaust stream.

Air bag

A device which is part of the passive safety system. In the event of an accident, sensors will cause the airbag to be deployed so that your head will be pillowed by the bag instead of hitting the dash.

Also see
driver air bag passenger-side air bag side impact air bag

Airbag

Also see
driver air bag passenger-side air bag side impact air bag

Airbag module

All the components that make up the airbag system Airbag, inflator, cover, and sensor. Also called airbag unit..

Airbag restraint system

A system which uses an airbag to restrain occupants in the event of a collision. They may be placed on the dash or doors or even in the shoulder strap. Also called passive restraint system..

Air-bag system

See	supple mental restraint inflatable air-bag system

Airbag unit

All the components that make up the airbag system Airbag, inflator, cover, and sensor. Also called airbag module..

Air bellows

A rubber bladder or sleeve filled with compressed gas or air. Found on some suspension systems to provide cushioning.

Also see
air suspension

Air bleed

See	adjustable off-idle air bleed auxiliary air bleeds compensating jet idle air bleed screw

Air bleed screw

See	idle air bleed screw

Airbox

The container which holds the air filter.

Air brake

[1] A system of braking which is usually found on large truck in which compressed air pushes against a brake piston or diaphragm in order to apply the brakes to stop or slow the vehicle.

[2] An extendable device, most commonly a hinged flap on wing or fuselage, controlled by the pilot, to increase the drag of an aircraft. Originally a means of slowing bombers to enable them to dive more steeply, it is an essential flight control on clean jet aircraft and sailplanes

[3] A mechanical brake operated by air-pressure acting on a piston

[4] An absorption dynamometer in which the power is dissipated through the rotation of a fan or propeller.

Airbrush

[1] A paint spray gun used for precise detailing work and custom painting.

[2] The act of using an airbrush.

Air bypass valve

( ABPV or ABV) a backfire-suppressor valve used in air injection systems. During high engine vacuum conditions such as deceleration, it vents pressurized air from the air pump to the atmosphere in order to prevent backfiring. At other times, it sends air to the exhaust manifold. On vehicles with a three-way catalyst, it sends air to the oxidation catalyst only when the engine warms up. Also called an anti-backfire valve, diverter valve, or gulp valve.

Air cap

See	external mix air cap internal mix air cap

Air capacitor

A capacitor in which the dielectric is nearly all air, for tuning electrical circuits with minimum dielectric loss.

Air capacity

See	breathing capacity

Air cell

A small auxiliary combustion chamber used in certain types of compression-ignition engines, for promoting turbulence and improving combustion.

Air charge temperature

( ACT) The temperature of the air being forced into the carburetor or fuel injection system. An ACT sensor measures this temperature.

Air charge temperature sensor

(ACTS) a thermistor sensor that inputs the temperature of the incoming air stream in the air filter or intake manifold to the computer. It can be located in the intake manifold (EFI systems) or the air cleaner. On carbureted vehicles, if the air is cold, it signals the choke to let off slowly. It then alters engine speed after the choke is off and below a certain temperature, dumps air from the air injection system to the atmosphere for catalyst protection.

Air cleaner

A device which filters the air entering the engine to remove airborne impurities, dust, dirt, and bumblebees. Also called air filter.
Also see
bath air cleaner
bath air cleaner
low-profile air cleaner
oil bath air cleaner
paper air cleaner
thermostatic air cleaner

Air cleaner bi-metal sensor

(ACL BI-MET) a component of a thermostatic air cleaner system. It senses the temperature of incoming fresh air and bleeds off vacuum when the air is warm. When the air is cold, the sensor directs vacuum to the air cleaner vacuum motor.

Air cleaner duct and valve vacuum motor

(ACL DV) a component of thermostatic air cleaner systems. It opens and closes the air duct valve to provide heated or unheated air to the engine in accordance with the temperature of the incoming air.

Air cleaner element

The replaceable filter which prevents impurities from the air which enters the combustion chamber. Also called air filter element.

Air cleaner horn

Many air cleaner canisters have a spout or horn extending from the edge of the canister into which the air is taken in.

Also see
heated intake

Air coil

Coil on some types of heat pumps used either as an evaporator or a condenser.

Air compressor

A device which compresses air and stores the air into a tank so that the compressed air can be used in a shop to fill tires, run tools, spray paint, etc. In a vehicle, it can be used in brake systems, leveling systems, automatic tire inflation systems, and air supply systems.

Air-conditioned

The state of exchanging warm air for cold so that a vehicle or home is cooler than the outside temperature.

Air conditioner

(A/C) or (Air)

[1] A device used to control temperature, humidity, cleanliness, and movement and sometimes the air purity, in an enclosed space

[2] A system of devices which causes a reduction or control of the temperature and humidity within the cab of a vehicle. It was first offered on the 1941 Packard. Two types are used in vehicles Receiver-dryer type and accumulator type.

Also see
compressor condenser

Air conditioner clutch compressor signal

(ACCC signal) the input to the computer regarding the status of the air conditioner clutch (engaged or disengaged).

Air-conditioning

A system or process for controlling the temperature, humidity, air movement, and sometimes the purity of the air in an enclosed space.

Also see
automatic air-conditioning

Air control

See	electric air control valve

Air control valve

( ACV) a vacuum-controlled diverter valve (or a combination bypass/diverter valve) in an air injection system that diverts air pump air to either the upstream (exhaust manifold) or downstream (oxidation catalyst) air injection points as necessary.

Also see
electric air control valve

Air-cooled apparatus

An electric apparatus in the heat caused by the losses is removed solely by natural or fan-assisted air flow.

Air cooled

See	air cooled engine

Air-cooled condenser

A heat exchanger which transfers the heat of compression from condensing coils to surrounding air. This may be done either by convection or by a fan or blower.

Air cooled engine

An engine which generally has large fins or ribs and is often exposed to the outside air. The heat of the engine is dissipated through the fins of the engine. In contrast, the heat in a liquid-cooled engine is reduced by channels throughout the inside of the engine through which liquid (antifreeze) passes. Most older Volkswagens and motorcycles use air cooled engines.

Air-cooled engine

See	air cooled engine

Air-cooled machine

A machine in which the heat caused by the losses is removed solely by natural or fan-assisted air flow.

Air cooler

[1] Mechanism designed to lower temperature of air passing through it

[2] The cold "accumulator" used in the Lindé process of air liquefaction for the preliminary cooling of the air.

Air cooling

The cooling of hot bodies by a stream of cold air, instead of liquid (water) cooling.

Also see
charge air cooling

Air core

Coil of wire not having a metal core.

Air core solenoid

Solenoid which has a hollow core instead of a solid core.

Air correction jet

A small orifice which permits air to enter the emulsion tube of a carburetor.

Aircraft

Any mechanically driven heavier-than-air flying machine with wings of fixed or variable sweep angle. Subdivision landplane, seaplane (float seaplane and flying boat), amphibian.

Air cushion

See	airbag

Air dam

An attachment called a "spoiler" which is usually located below the front bumper. Its design shape and placement helps to reduce the flow of air under the vehicle. It may help to increase the flow of air to the radiator and engine compartment, affect aerodynamic drag, or affect positive and negative lift.

Air deflector

A panel which is positioned at an angle on the roof of a truck or on the front of the hood to cause the air to flow over the vehicle. The hood air deflector (often made of transparent plastic) is designed to prevent bugs from hitting the windshield. British term is "air shield."

Air diffuser

Air distribution outlet or grille designed to direct airflow into desired patterns.

Air drag

Resistance to the motion of a body passing through the Earth's atmosphere, most serious in the lower regions, producing changes in the geometry of the orbit, even causing the body to re-enter. More generally the term atmospheric drag is used in reference to other planets.

Air dry

Allowing paint to dry at ambient (surrounding) temperatures, without the aid of an external heat source.

Air-dry

Allowing paint to dry at ambient (surrounding) temperatures, without the aid of an external heat source.

Air drying adhesives

Adhesives that can be dried at room temperature without the use of heat. This type of adhesive consists of solid particles dissolved or dispersed in a liquid. When the liquid evaporates, it leaves the dry adhesive film. Most elastomer based adhesives are of this type.

Air duct

A tube or channel which permits heated and ventilated air to enter the passenger compartment, building, or machinery to provide heating, cooling, or ventilation.

Aired up

Said of an oil plunger pump which no longer sucks because gas or air has filled the suction chamber.

Air ejector

A type of air pump used for maintaining a partial vacuum in a vessel through the agency of a high-velocity steam jet which entrains the air and exhausts it against atmospheric pressure.

Air engine

[1] An engine in which air is used as the working substance. Rapid heating from an external source expands the air in the cylinder with consequent motion being imparted to a piston. After transfer to a compression cylinder, for rapid cooling, the air is returned to the working cylinder for the next cycle. Also called hot-air engine.

[2] A small reciprocating engine driven by compresse