An abbreviation for:
A symbol for Carbon.
To raise the arch of a chassis frame to provide added clearance over the rear axle and lower the overall height of the frame side rails.
The pattern used to grind pistons in an oval or cam shape, with a 0.009 inch (0.23 mm) difference between the thrust face and pinhole side.
A term often used to describe an outside snap ring.
A C-shaped clip used to retain the drive axles in some rear-axle assemblies.
A clip used to secure a pin in linkage, such as for carburetion.
The structural support just behind the rear door that supports the greenhouse.
A term often used for c-pillar.
A combination of two or more trailers in which the dolly is connected to the first trailer by means of two pintle hooks or coupler-drawbar connections, resulting in only one pivot point.
A computer-controlled, coil-ignition system that uses a computer to monitor, maintain, and adjust ignition timing.
An abbreviation for Clean Air Act Amendments.
The driver/passenger compartment of a truck or off-road vehicle.
Short for taxicab.
Cab Behind Engine (CBE)
A type of truck with the cab behind the engine.
Cab Over Engine (COE)
A type of truck with the cab above the engine.
An assembly of two or more wires that may be insulated or bare.
Cable Clamp
A device used to clamp around a cable to transmit mechanical strain to all elements of the cable.
The helical wrapping together of two or more insulated wires.
A European term for convertible.
An acronym for Corporate Average Fuel Economy.
The metal structure that separates the balls of a roller bearing assembly.
A shortened term for roll cage.
Caged Roller Clutch
A one-way clutch having the rollers and springs contained as a unit.
To check, test, or adjust the initial settings of a unit or system.
The adjustment of a device or instrument so that output is within a designated tolerance for specific input values.
California Air Resources Board (CARB)
A California agency responsible for regulations intended to reduce air pollution, especially that created by motor vehicles.
Non-rotational components of disc brakes that straddle the disc and contain hydraulic components forcing the brake pads against the rotor to slow or stop the vehicle.
A measurement of heat; the amount of heat required to raise 1 gram of water (H2O) 1°C.
The eccentric element of a one-way roller clutch that carries the profiles through which the rollers transmit torque.
An abbreviation for camshaft.
Cam and Kit
A specially ground camshaft, complete with a set of compatible camshaft valve train components, including lifters and springs.
Cam Angle
A term often used for dwell angle.
Cam Button
A device that keeps a camshaft properly positioned in an engine.
Cam Duration
The amount of time, measured in crankshaft degrees, that a camshaft holds an exhaust or intake valve open.
Cam Follower
A term often used for valve lifter.
Cam Ground
Pistons machined to a slightly out-of-round shape to permit them to expand with engine heat without getting stuck against the cylinder walls.
Cam Lift
The distance, in thousandths of an inch, a cam lobe raises the valve lifter off the base circle.
Cam Sensor
A camshaft-mounted sensor that signals when cylinder number one is at TDC.
Cam-Ground Piston
A piston ground slightly oval or elliptical in shape as a means to compensate for expansion caused by heat.
Cam-Lobe Face and Nose Taper
The slant, about 0.002 inch (0.051 mm), designed across the cam-face contacting surface, from the cam front to rear edge, to promote lifter rotation.
Cam-Shaped Pocket
The recess in an overrunning clutch race, large at one end, tapering to small at the other end.
The outward or inward tilt of the wheels, in degrees, on a vehicle as viewed from the rear or front.
Camber Angle
The amount, measured in degrees from the vertical, that the top of a tire is tilted outward (positive) or inward (negative).
Camber Compensator
A device that is used to maintain the proper camber of the rear wheels of a vehicle equipped with swing axles.
Camel Hump Heads
High performance heads by Chevrolet, identified by two humps on the outside end of the casting.
A strip of new rubber used to recap a tire.
An engine with an overhead camshaft.
A shaft having lobes driven by the crankshaft via gears, chains, or belts that, in turn, opens and closes the intake and exhaust valves at proper intervals.
Camshaft Duration
The amount of time, measured in degrees of crankshaft rotation, an intake or exhaust valve is held open.
Camshaft Lift
How far a valve is pushed open, as determined by the height of the cam lobe and the geometry of the rocker arms on a push rod engine, or the cam followers on an overhead cam engine.
Camshaft Plug
A plug found in the rear of the engine block, at the camshaft, to retain and direct oil to the rear camshaft bearings.
A term often used for nitro or nitromethane, a highly combustible liquid used as the main ingredient in drag-racing fuel.
Can Tap
A device used to pierce, dispense, and seal small cans, such as refrigerant.
Can Valve
A term often used for can tap.
An abbreviation for Canadian American Challenge Cup.
Canadian-American Challenge Cup (Can-Am)
A former annual series of SCCA sanctioned road races, held in the United States and Canada, for unlimited sports cars with no restriction on engine displacement.
Candy-Apple Red
A popular trade name for a gold-color-base, clear-coated, metallic-red paint job.
A container filled with charcoal in an evaporative control system used to filter and trap fuel vapors.
Canister Filter
A canister-like device containing a filter media which removes suspended particles of contaminants from air, fuel or oil.
Canister Purge Solenoid
A solenoid valve that admits fuel vapors to the canister for processing.
Canted Valves
A cylinder-head layout where the intake valves are at one angle, while the exhaust valves are at another angle.
Cantilever Tire
A tire with a tread wider than the rim.
A cover or lid for a container.
That part of the distributor that directs electrical energy to the spark plugs.
A small metal part, usually of hardened steel, that acts as an interference between the valve-stem end and the rocker arm.
The half round, removable part of a connecting rod or main bearing.
An electrical device for the temporary storage of electricity. Used in a conventional ignition system in the distributor to reduce arcing across the points and in the electrical charging system to reduce radio interference.
Capacitor Discharge Ignition (CDI)
A term used for a capacitor discharge ignition system.
Capacitor Discharge Ignition System
An ignition system that stores its primary energy in a capacitor.
The ability to perform or to hold.
Refrigeration produced; measured in tons or Btu per hour.
Cape Top
The fixed enclosure over the rear seat.
Capillary Action
The force by which liquid, in contact with a solid, is distributed between closely fitted surfaces of the joint, while being brazed or soldered.
Capillary Attraction
Another term for capillary action.
Capillary Tube
A tube with a calibrated inside diameter and length used to control the flow of refrigerant.
A tube that connects the remote bulb to the thermostatic expansion valve.
A tube that connects the remote bulb to the thermostat.
An abbreviation for Clean Air Performance Professionals.
Captive Fasteners
A preassembled fastener used in conjunction with mating fasteners such as bolts, studs, nuts, or screws.
A term used for carcinogenic effects.
Car Care Council
A non-profit organization to educate the general public about the importance of preventive maintenance.
Car Wash Owners and Suppliers Association, Inc. (COSA)
A trade association of car wash manufacturers, operators, and suppliers.
An abbreviation for California Air Resources Board.
An abbreviation for carburetor.
A compound of solid elements, usually metal, with carbon.
A mixture of very hard metals, such as tungsten carbide.
Carbolic Acid
A very toxic acid (C6H5OH); an ingredient used in cold-dip tanks.
A natural element.
A by-product of combustion.
Any form of graphite or undefined carbon.
Carbon Arc Cutting and Welding
A cutting process that uses a carbon electrode.
A welding process that uses an arc between a carbon electrode and the weld pool.
Carbon Canister
A canister filled with carbon, used to absorb and store fuel vapors that are normally discharged into the air.
Carbon Dioxide (CO2)
A harmless, odorless gas composed of carbon (C) and oxygen (O); a product of complete combustion.
Carbon Fiber
A very strong, lightweight, synthetic fiber often used in race cars, such as Formula One and Indy cars, because of its lightweight and high strength.
Carbon Monoxide (CO)
An odorless gas composed of carbon (C) and hydrogen (H), formed by the incomplete combustion of any fuel containing carbon. This major air pollutant is potentially lethal if inhaled, even in small amounts.
Carbon Tracks
A condition where there is a carbon build up, or track, running from one point to another, acting as an electrical circuit and thereby causing a short circuit.
Carbon-Fouled Plug
A spark plug having a dry, fluffy black deposit; the result of over-rich carburetion, over choking, a sticking manifold heat valve, or clogged air cleaner.
The formation of carbon deposits as a result of by-products of combustion in an engine.
Carbonyl Chlorofluoride (COC1F)
A toxic by-product of Refrigerant-12, and other CFCs; toxic if allowed to come into contact with an open flame or heated metal.
Carbonyl Fluoride (COF2)
A toxic by-product of Refrigerant-12, and other CFCs; toxic if allowed to come into contact with an open flame or heated metal.
The action that takes place in a carburetor while converting liquid fuel to a vapor and mixing it with air to form a combustible mixture.
A vacuum-dependent device used to mix fuel with air to form a vapor that is ideal for combustion.
Carburetor Emission Device
An item attached or adjacent to the carburetor that establishes operating conditions intended to reduce exhaust emissions.
Carburetor Icing
A condition caused by high-velocity fuel flow; ice is formed on the outside of the carburetor.
Carburetor Insulator
A spacer between the carburetor and intake manifold to reduce engine heat to the carburetor.
Carburetor Kickdown
A moderate pressing of the accelerator pedal to change engagement of the fast-idle screw from high step to low step of the cam.
Carburetor Kit
A set of gaskets and parts necessary to rebuild a carburetor.
Carburetor Restrictor Plate
A term often used for restrictor plate.
Carburetor Spacer
A steel, aluminum, or plastic plate used to raise the carburetor above the normal opening of the intake manifold.
Carburetor Tag
A tag affixed to the carburetor to identify the model for parts and specifications for service.
Carburetor Vacuum
A ported vacuum, obtained from a carburetor source above the throttle plate, present after the throttle is partially open.
Carburetor-Heated Air
A system in which heated air is directed from the manifold to the carburetor for improved performance with a leaner air/fuel mixture.
A British spelling of carburetor.
A British spelling of carburetor.
To treat or combine with carbon.
Carburizing Flame
A reducing oxyfuel-gas flame in which there is an excess of fuel gas, resulting in a carbon-rich zone extending around and beyond the cone.
A tire casing to which the rubber tread and sidewall are bonded.
The inner part of the tire that holds the air for supporting the vehicle.
The empty remains of a stripped vehicle.
Carcass Plies
That which surrounds both beads and extends around the inner surface of the tire to provide load-carrying capabilities on the rim.
A substance or agent that produces or incites cancer.
A term often used for carcinogen.
Carcinogenic Effects
Causing cancer or increasing the incidence of cancer in the population.
Cardan Joint
A universal joint having two yokes at right angles to each other, with a cruciform-shaped joint in the middle.
Cardan Universal Joint
A term used for Cardan joint.
Cargo Weight Rating (CWR)
A truck's carrying capacity, in pounds.
Carolina Stocker
A car built for drag racing, without regard for any recognized rules.
Carrera Panamericana
The legendary Mexican road races held in the early 1950s that ran the full length of Mexico.
Vintage car races held on the public highways of northern Baja, California.
A part that holds, positions, moves, or transports another part or parts.
Carrier Bearing
A bearing that supports the ring-gear carrier in the differential.
Carrier Housing
Cast-iron rear axle assembly section that contains the working parts of the differential.
Carry the Wheels
To do a wheel stand; a drag-racing term.
A tradename once used for a large station wagon built on a truck chassis; predecessor of the Suburban.
Carson Top
A removable, non-folding, padded soft top, used on many customized convertibles and roadsters.
An acronym for Championship Auto Racing Teams.
Cartridge Filter
A filter media that includes yarns, felts, papers, resin-bonded fibers, woven-wire cloths, and sintered metallic and ceramic structures for cleaning impurities from air or liquid. Performance obtained by a disposable cartridge filter may range from 500 µm to 1 µm or less.
Cartridge Roll
A rolled piece of sandpaper used to deburr or blend sharp edges, such as when porting and polishing a head.
CAS Registration Number
The Chemical Abstract Service Number used to identify a chemical.
Two devices in tandem; the output of one device connected to the input of the other.
Case Harden
A heat-treating process that hardens the outer surface of metal, while leaving the core soft and ductile.
The outer part of a tire assembly made of fabric or cord to which the rubber is vulcanized.
The outer housing or shell containing an assembly.
Cast Iron
A term used for a family of cast ferrous alloys containing at least 2% carbon, plus silicon and sulfur; may or may not contain other alloy elements.
Cast-Iron Guide
A valve guide made of cast iron.
Formed to resemble a castle battlement.
Castellated Nut
A nut with six raised portions or notches through which a cotter pin can be inserted to secure the nut.
The angle between the steering-spindle axis and the wheel vertical as viewed from the side.
Caster Angle
The amount, measured in degrees from the vertical, that the upper ball joint is located behind or ahead of the lower ball joints.
A metal object formed to the required shape by pouring or injecting liquid metal into a mold.
Casting Flash
A thin metal exuding at the parting edges of a casting mold, evident when the part is removed from the mold.
Casting Number
A part number that has been cast into a part during manufacture.
Castor Oil
A lubricant made from the castor bean.
An abbreviation for catalytic converter.
An illustrated or ordered list of items and descriptions with sufficient data to identify the item.
The action of a catalyst.
A lead-sensitive substance, such as platinum, palladium, or rhodium, that accelerates or enhances a chemical reaction without being changed itself. When used in a catalytic converter, it can reduce the level of harmful pollutants in the exhaust.
Catalytic Converter
An automotive exhaust-system component, made of stainless steel, containing a catalyst to reduce oxides of nitrogen (NOX), and/or hydrocarbon (HC), and carbon monoxide (CO), in tailpipe emissions.
Catch Can
A container on a race car's radiator or fuel tank to prevent liquid from spilling on the ground during a pit stop.
Catch Tank
A term often used for catch can.
Catenary Effect
The curve that a length of chain assumes between its suspension points.
The negatively charged cell from which current flows in an electrolytic cell.
Cathode Ray Tube (CRT)
A vacuum tube used in electronic equipment and some electronic readouts to display information.
Caulking Compound
A thick, viscous material used as a sealer at joints, such as around the windshield.
A salt-based chemical for cleaning engine parts.
A cleaner that may be used for most metals, except aluminum.
Caution Flag
A yellow flag displayed to race-car drivers to indicate a slow down. Also used to indicate no passing, due to a problem or mishap on the race track.
The presence of air in a liquid during pumping, which can inhibit the flow of the liquid.
An abbreviation for cab behind engine.
An abbreviation for completely built up.
An abbreviation for cubic centimeter.
The measure of the volume of a combustion chamber.
An abbreviation for close cup, a method of determining the flash point of a flammable liquid.
CC-Grade Oil
An American Petroleum Institute (API) specification standard for diesel motor oil.
To measure or calculate the volume of a combustion chamber in cubic centimeters.
An abbreviation for computer-command control.
An abbreviation for the Classic Car Club of America.
An abbreviation for constant current electronic control.
An abbreviation for cycling clutch fixed orifice tube.
An abbreviation for cycling clutch orifice tube.
An abbreviation for counterclockwise.
A symbol for coefficient of drag.
CD-Grade Oil
An API performance-specification standard for diesel motor oil.
An abbreviation for capacitor discharge ignition.
An abbreviation for combustion emission control.
Cellular Core
A type of radiator core.
Cellulose Fiber
Transparent material made of camphor and guncotton, formed into thread-like filaments.
The metric scale for temperature where water (H2O) freezes at 0°C and boils at 100°C.
A process for introducing elements onto the surfaces of metals by high-temperature diffusion.
An abbreviation for counterelectromotive force.
Center Bolt
A term that generally refers to a leaf-spring center bolt.
Center Electrode
The insulated part of a spark plug that conducts electricity toward the electrode gap to ground.
Center Link
A steering linkage that is connected to the tie-rod ends that transfers the swinging motion of the gear arm to a linear, or back-and-forth, motion.
Center of Gravity (CG)
The exact point around which an object, such as a vehicle, is perfectly balanced in every direction.
Center of Wheelbase
The exact point midway between the front and rear wheels of a vehicle.
Center to Center
The distance between two centers, usually cylinder bores.
Center-Mount Components
The modular installation of a system, such as heating or air conditioning, whereby the evaporator is mounted in the center of the firewall, on the engine side, and the heater core is mounted directly to the rear in the passenger compartment.
Center-Point Steering
A steering geometry in which the steering axis passes through the center of the tire contact points.
Centering Cones
Tapered pieces of metal, designed to slide onto a shaft to align and hold parts perpendicular to the axis of the shaft.
To bore align.
To blueprint.
The axis of an object.
Same as intake centerline when referring to a camshaft.
A line indicating the exact center.
Former name for 100 point Celsius scale, the point at which water (H2O) boils (100°C).
A term often used incorrectly to indicate a metric temperature value. The proper term for a metric temperature value is Celsius.
A metric unit of linear measure equal to 0.3937 inch.
Centipoise (CP)
A metric unit of dynamic viscosity. It is used by the paint industry to measure the viscosity of paint, and by the oil industry to indicate the low-temperature operating characteristics of oil.
A metric unit of kinetic viscosity used to indicate the high-temperature operating characteristics of oil.
Central Port Injection
An early fuel-injection system installed on the 4.3L Chevrolet Vortec V–6, using one throttle-body, injection-style injector to pulse fuel directly to individual nozzles at the intake ports.
Central Processing Unit (CPU)
The component of a computer system with the circuitry to control the interpretation and execution of instructions.
A term often used to describe centrifugal force.
Centrifugal Advance
A mechanical means of advancing spark timing in a conventional distributor with flyweights and springs.
Centrifugal Clutch
A clutch that utilizes a centrifugal force to apply pressure against a friction disc in proportion to the speed of the clutch.
Centrifugal Filter
A rotating filter that relies on centrifugal force to separate impurities from the fluid, usually oil.
Centrifugal Filter Fan
A fan found on the air-pump drive shaft used to clean the air entering the air pump.
Centrifugal Force
The outward force, away from the center (axis) of rotation, acting on a revolving object, increasing as the square of the speed.
Centrifugal Supercharger
A mechanically driven, forced-induction system using centrifugal force to increase air pressure.
Centrifugally Disengaging
A one-way roller clutch in which the rollers disengage with the race, in over-running conditions.
Centrifugally Engaging
A one-way roller clutch, in which the rollers make or maintain contact with the race in over-running conditions.
Centrifuge Brake Drum
Combining the strength of steel with the friction characteristics of cast iron by spraying a lining of cast iron on the inside of a steel drum while hot.
Century Mark
100 miles per hour.
A material composed of silica and earth elements used as an insulator, as in spark plugs.
Ceramic Insulator
The non-conductive material used, for example, in spark plugs, to insulate the center electrode from the ground.
A primary reference fuel (C16H34) for describing the ignition quality of diesel fuel.
Cetane Number
The number, generally from 40 to 60, that relates to the ignition quality of diesel fuel.
An abbreviation for the chlorofluorocarbon family of refrigerants.
An abbreviation for continuous fuel injection.
An abbreviation for central fuel injection.
An abbreviation for cubic feet per minute.
An abbreviation for center of gravity.
Chain Casing
An enclosure, housing, or guard for a chain drive containing the lubricating system and providing protection from contamination.
Chain Drive
A drive system consisting of a drive, and a driven sprocket and chain, such as a motorcycle or bicycle drive.
Chain Guide
A device used to support and guide a chain, such as a timing chain, to reduce or prevent whip.
Chain Length
The distance between the joint centers at each end of a taut chain strand.
Chain Pitch
The center-to-center dimension between chain links or joints.
Chain Tensioner
A device used to maintain chain tension, such as a guide rail or a hydraulic pressure piston with a rubbing shoe.
To remove a hard edge from a part.
Chamfer Face
A beveled surface on a shaft or part that allows for easier assembly.
Champ Car
A championship car.
Early term for an Indy car.
Championship Auto Racing Teams (CART)
The sanctioning body of such events as the annual Indycar World Series.
Championship Trial
The traditional designation for the annual series of races for Indycars, sanctioned by AAA, USAC,and CART, now known as the Indycar World Series.
Change of State
The rearrangement of molecular matter as it changes between any of the three physical states: solid, liquid, or gas.
To lower the body over the chassis.
Chapman Strut
A type of rear suspension having a telescoping strut that is attached to the chassis at the top and to two links at the bottom, restricting lateral and longitudinal movement.
Charcoal Canister
A container, usually located in the engine compartment, containing activated charcoal. The charcoal absorbs or traps vapors from a vehicle's sealed fuel system, generally when the engine is turned off. This is a basic component of evaporative emissions control systems.
To fill a battery with electrical energy.
To fill an air conditioner with a specific amount of refrigerant or oil by volume or weight.
The amount of fuel/air mixture to be burned in a cylinder.
To drive aggressively.
Charge Temperature Sensor
A sensor that sends a signal to the computer causing it to vary the temperature of the intake stream.
Charge the Trailer
To fill the trailer air-brake system with air.
Charge Tolerance
The accuracy, plus/minus, permitted in the specified amount of liquid or gas that is charged into a system.
A term often used to describe a battery charger.
A top performance driver; one who pushes his car to the limit.
The act of placing a charge of refrigerant or oil into an air-conditioning system.
The act of refreshing a battery.
Charging Cylinder
A container with a visual indicator, for use when a critical or exact amount of fluid must be measured.
Charging Hose
A small-diameter hose, between the system and source, that is constructed to withstand high pressures.
Charging Station
A unit containing a manifold and gauge set, charging cylinder, vacuum pump, and leak detector used to service air conditioners.
A process to restore damaged threads.
Chasing Threads
A manual process using a tap or die to restore threads in a nut or on a bolt.
The lower structure of a vehicle to which the body and running gear are attached.
Chassis Dynamometer
A drive-on device, used to measure net road horsepower and torque, delivered by the drive wheels.
Chassis Dyno
A term often used for chassis dynamometer.
Chassis Lubrication
An element of preventive maintenance.
The procedure of applying the correct type and amount of grease to the chassis lubrication points at recommended intervals.
Adding or changing fluids.
Miscellaneous services including tire pressure and safety checks.
Chassis Tuning
Adjusting the running-gear geometry of a vehicle to compensate for different road conditions.
Chassis Waddle
A term often used when describing lateral runout or tire waddle.
Cheater Slick
A tire that is constructed of the same sticky rubber as a racing tire, but has a shallow tread cut into it to make it street legal.
To verify that a component system, or measurement, complies with specifications.
Check Ball
A device that maintains air or fuel pressure at a predetermined level.
A device that permits the flow of fluid or vapor in one direction only.
Check Relay
A term often used for check-valve relay or vacuum-check relay.
Check-Engine Light
A warning light, generally located in the instrument cluster, that indicates a potential engine or system problem.
A valve that permits the passage of a gas or fluid in one direction, but not in the other.
A device located in the liquid line or inlet to the drier of some systems to prevent refrigerant flow in the opposite direction when the unit is turned off.
Check-Valve Relay
An electrical switch to control a solenoid-operated check valve.
A term often used for checkered flag.
Checkered Flag
A flag waved at a driver, in closed-course competition, to indicate that he/she has completed the race.
The first driver shown the flag is the winner of an event.
The plate-like part of a crankshaft that connects the journals, often serving as a counterweight.
Chem Mill
A term used for chemical milling.
Chemical Fire Extinguisher
A type of fire extinguisher that uses dry chemicals that displace oxygen, thereby extinguishing a fire.
Chemical Gasket
A liquid or putty-like substance, similar to RTV, used as a substitute for a solid gasket.
Chemical Hazards
Hazard concerns primarily, but not exclusively, from solvents, fuels, asbestos, and antifreeze.
Chemical Instability
An undesired condition that exists when a contaminant causes a fluid, such as refrigerant, to break down into a harmful chemical.
Chemical Milling
A term often used for acid dip.
Chemical Reaction
The formation of a new substance when two or more substances are brought together.
The emission of light energy, other than by burning, during a chemical reaction.
In unusually fine shape.
As good or better than new.
Not used before.
An artificial series of turns on a straight track, in road racing events, that are marked by pylons or temporary curbs.
Child-Safety Latch
A power-door lock system that prevents the door(s) from being opened from the inside, regardless of the position of the door-lock knob.
Chilled Cast Iron
Cast iron that has been hardened using dry ice.
Chimney Effect
The tendency of air or gas to rise when heated.
A nick in paint work.
A microprocessor part.
Metal removed during a milling or machining process.
Chirp Rubber
To quickly shift gears during hard acceleration, so the tires momentarily break loose and leave slight streaks of rubber on the pavement.
Chirp the Tires
A phrase sometimes used for chirp rubber.
Chit Box
A recreational vehicle, such as a mobile home or trailer.
A term often given to a Chrysler product.
Chlorofluorocarbon (CFC)
A family of chemicals that includes the automotive air-conditioning refrigerant, R-12. Designated CFC, they have been blamed for a deterioration of the Earth's protective ozone layer and have been phased out of production by international agreement.
A manually or thermostatically controlled device mounted to a choke shaft having vanes at the mouth of a carburetor that closes when the engine is cold. This increases the gasoline content in the air/fuel mixture that aids in starting when fuel evaporation is low.
Choke Heater
A device that warms the thermostatic coil of an automatic choke, causing it to open quickly. Later-model carburetors often have an electrical heating element and/or a timer circuit.
Choke Piston
A vacuum-controlled piston used to partially open the choke when the engine starts.
Choke Plate
A butterfly valve that closes at the inlet of the carburetor to enrich the air/fuel mixture, as when starting the engine.
Choke Pull-Off
A vacuum motor that opens the choke plate during full acceleration.
Choke Rod
A rod connected to the choke plate.
Choke Shaft
A shaft at the mouth of a carburetor on which the choke plate is mounted.
Choke Valve
A term often used for choke plate.
To lower the greenhouse of a vehicle.
To cut in front of another vehicle in a closed-course race.
Chop Shop
A facility where stolen vehicles are stripped, dismantled, or otherwise prepared for illegal sale.
Chop, Channel, and Enamel
The full restyling treatment of a car.
Chopped Flywheel
To machine the surface of a flywheel to lighten it.
Christmas Tree
The electrical countdown system used in drag racing.
A simple term for chromium.
Chrome Carnival
A term that applies to a rod and custom show.
Chrome Molly Steel
A steel alloy that contains chromium and molybdenum.
Chrome Plate
To apply a thin layer of chrome for appearance.
Chrome Rings
Piston rings that are plated with chromium.
Chrome Steel
A steel alloy that contains chromium.
A term used for chrome-plated wheels.
A basic element, Cr.
A metal used in alloys to provide a durable and hard surface.
An alloy used to plate metal to provide a shining surface.
The trade name of a popular brand of racing timing equipment.
A term often used for Chrysler Corporation.
A fast, straight stretch of track on an oval track or road course.
A parachute, as used to slow drag and lake cars.
The starting position for a dragster.
An abbreviation for cubic inch.
An abbreviation for cubic-inch displacement.
Circle Burning
An oval race track.
A split-steel snap ring that fits into a groove, to hold various parts in place.
A complete path for an electric current.
A race course.
Circuit Board
A generic term used for printed circuit board.
Circuit Breaker
An electrical switch-like protective device that automatically opens to interrupt the circuit if current exceeds its rated limit.
An abbreviation for continuous injection system.
An abbreviation for continuous injection system-electronic.
A metal or material covered with another metal by bonding.
Clad Metal
A metal that is covered with another metal or alloy of different composition, applied to one or both sides by casting, drawing, rolling, surfacing, chemical deposition, or electroplating.
The application of a surfacing material, to impare corrosion and/or heat resistance.
A screw-, cam-, or lever-actuated device for temporarily holding parts together.
A group of competition cars with basically the same specifications and performance potentials.
Class F Red Insulating Enamel
A paint that is used to seal the interior of an engine and to aid in rapid oil return to the crankcase.
A fine car.
An important racing event, such as the Indy
3. Certain cars built between 1925 and 1948.
Classic Car Club of America (CCCA)
An organization that is dedicated to the preservation of specific American and European luxury cars manufactured between 1925 and 1948.
Classifying Vehicles
Any or all of the methods used to classify vehicles, such as by weight or fuel consumption. See the appropriate heading for a specific definition.
To flush.
To purge.
Free of dirt, grime, or grease.
Clean Air Act
A term used for Clean Air Act Amendments (CAAA). A Title IV amendment, signed into law in 1990 by President George Bush, that established national policy relative to the reduction and elimination of ozone-depleting substances.
Clean Air Performance Professionals (CAPP)
An association of repair shops and technicians promoting inspection and maintenance programs to help protect our environment.
Clean Room
An enclosed, ventilated or air-conditioned area, free of airborne particles where delicate components, such as engines and automatic transmissions, can be assembled with minimal risk of contamination.
Clear Coat
A hard, transparent coating that is applied to a painted surface to enhance the illusion of visual depth and/or protect the surface.
The space between mating parts, such as between a journal and a bearing, that allows freedom of movement or prevents interference.
Clearance Ramp
The area of a mechanical-lifter camshaft lobe that makes the progression from the base circle to the edge.
Clearance Volume
The total-volume measurement above a piston at top dead center, (TDC), including the area of the combustion chamber.
Clearing Time
The time it takes a circuit breaker to sense an over current, until circuit interruption.
Cleveland V-8
A popular 351 cid V ??8 engine manufactured in Cleveland by Ford.
A major body repair where the front or rear of a vehicle is replaced with the front or rear of another vehicle of the same make and model.
A device for telling the time of day.
A term often used for speedometer.
A device that generates a basic periodic signal used to control timing of all operations in a synchronous system or computer.
Clock Spring
A device, located between the steering column and steering wheel, that conducts electrical signals in an air-bag system to the module, while allowing steering-wheel rotation. This provides electrical continuity in all steering-wheel positions.
Close Coupled
A limited rear-seating space, such as in a club coupe or two-plus-two.
Close Ratios
A transmission, usually used in drag racers, with close spacing between the speeds of the gears, allowing for minimum engine rpm reduction when shifting.
Close the Door
To immediately pull in front of an opponent after overtaking, preventing him/her from repassing.
To move over while entering a curve to block an opponent just as he/she pulls alongside on the inside to pass, preventing him/her from doing so. Also known as close the gate.
Close the Gate
A term often used for close the door.
Closed Course
An oval track or road race circuit.
Closed Loop
The basic principle of electronic engine management in which input from an oxygen sensor allows the engine-control computer to determine and maintain a nearly perfect air/fuel ratio.
A computer condition in which the air/fuel ratio is being controlled on the basis of various inputs to the computer.
A continuous circuit from beginning to end, and beyond.
Closed-Camber Head
A cylinder head having a combustion chamber with a very large quench or squish area.
Closed-End Spring
Coil springs having end loops next to the coils.
Closed-Loop Fuel System
A computerized air/fuel metering system based on monitoring the temperature and composition of the exhaust gases.
Cloud Point
The low temperature at which diesel fuel begins to produce wax crystals.
The temperature at which wax begins to separate from oil.
Club Coupe
A two-door, four- or five-passenger vehicle with limited rear seating.
A poorly performing car.
The family buggy.
Cluster Gear
A set of three or four gears on a common shaft in a manual transmission.
A device for connecting and disconnecting the power flow between the engine and standard transmissions, used during starting, shifting, and stopping.
A device used to connect two collinear shafts to a driving mechanism such as a motor, engine, or line shaft, and to disconnect them at will.
An electromagnetic clutch used to engage and disengage the compressor, to turn the air conditioner on and off.
Clutch Armature
That part of an electro-magnetic clutch that is attached to the compressor crankshaft and is pulled into contact with the rotor when engaged.
Clutch Cable
A cable that actuates the clutch fork of a manual-transmission system.
Clutch Can
A term often used for bell housing.
Clutch Coil
A unit consisting of many windings of wire fastened to the front of the air conditioning compressor. When current is applied, a magnetic field is set up that pulls the armature into the rotor to engage the clutch. Also known as clutch field.
Clutch Disc
Circular-shaped component, with a friction facing on each side, that transfers power from the flywheel and pressure plate to the splined clutch shaft.
Clutch Field
A unit consisting of many windings of wire fastened to the front of the air-conditioner compressor. When current is applied, a magnetic field is set up that pulls the armature in to engage the clutch. Also known as clutch coil.
Clutch Fork
A lever in the clutch that actuates the release bearing.
Clutch Gear
A gear or gears found on the clutch shaft.
Clutch Housing
Cast-iron or aluminum shell that surrounds the clutch assembly located between the engine and transmission.
Clutch Hub
A special hub used in certain limited slip-differential applications, such as single-pack types located between the splined discs and side gear.
Clutch Off
To get a fast start by engaging the clutch suddenly, such as at the start of a drag race.
Clutch Packs
A series of clutch discs and plates, installed alternately in the clutch housing, to act as a driving or driven unit.
Clutch Pedal
A pivoting component inside the vehicle that the driver depresses with his/her foot to operate the clutch.
Clutch Piston
An assembly in the multiple-disc clutch drum that is moved by oil pressure to engage the clutch and returned to a released position by mechanical-spring force.
Clutch Plate
A pressure plate that forces the clutch disc against the flywheel.
A term often used for clutch armature.
Clutch Rotor
That freewheeling portion of the air-conditioning system clutch, in which the drive belt rides, that mates to the armature when power is applied to the coil.
Clutch Shaft
The main shaft on which the clutch is assembled.
Clutch Slippage
A term given to the condition when, although engine speed is increased, increased torque is not transferred through to the driving wheels.
Clutch-Control Unit
A computer that controls clutch operation.
Clutch-Cycle Pressure Switch
A pressure activated switch that controls the air-conditioner-compressor clutch action to prevent evaporator icing.
Clutch-Cycle Switch
An electrical switch, pressure or temperature actuated, that cuts off the air conditioning compressor at a predetermined evaporator temperature.
Clutch-Cycle Time (total)
The time between when an air-conditioner clutch engages and when it disengages, then reengages; a time equal to one on and one off cycle.
Clutch-Release Bearing
A component, attached to the clutch-release fork, that contacts and then moves the release levers when the clutch pedal is depressed.
Clutch-Release Fork
A pivoting clutch housing component that transfers motion from the free-play adjusting rod on the clutch linkage to the attached clutch-release bearing.
Clutch-Relief Check valve
A valve that releases to prevent the buildup of pressure in a multiple-disc clutch assembly.
Clutch-Safety Switch
A term often used for neutral start switch or neutral safety switch.
An abbreviation for centimeter.
An abbreviation for compressed natural gas.
A symbol for carbon monoxide.
The symbol for carbon dioxide.
A bus.
A motor home.
An enclosed, two-door sedan of yesteryear.
A large, four-wheeled carriage; the forerunner of the modern vehicle.
Coach Builder
A manufacturer of fine custom-automotive bodies.
The product of a coach builder.
A paint that is used to provide beauty or weather protection to a vehicle or to its parts.
Any material applied to a metal surface to provide protection against the elements.
Coaxial Cable
A cable consisting of two conductors concentric with, and insulated from, each other.
The driver's compartment of a vehicle.
Code Installation
In general, an installation that conforms to the state and federal regulations and codes to insure safe and efficient conditions.
Code of Federal Regulations
Regulations that are generated, published, and enforced by the United States government.
An abbreviation for cab over engine.
Coefficient of Drag (Cx)
A measure of the air resistance of a moving vehicle; a measure of how much air is moved as the vehicle moves from one point to another.
Coefficient of Friction
The measure of the resistance of one surface moving against another.
Coefficient of Water/oil Distribution
The ratio of the solubility of a chemical in water compared to its solubility in oil.
A gear, particularly the final drive gear.
A term often used to describe a spring or an ignition coil.
Coil Bind
A condition where springs are compressed to the point that the coils touch.
Coil Failure
A defective ignition coil.
Also see coil spring failures.
Coil Over Shock
A suspension component that consists of a shock absorber inside a coil spring.
Coil Spring
A spring-steel bar or rod that is wound into the shape of a coil to provide an up-down springing effect. Found on most vehicle suspensions, these springs are used to support the car's weight, maintain height, and correctly position all other suspension parts, but are little help in supporting side-to-side or lateral movement.
Coil Tower
The high-voltage, center terminal of a conventional ignition coil.
Coil-Preload Springs
Coil springs, located in the pressure-plate assembly, made of tempered-steel rods formed into a spiral that resists compression.
Coil-Spring Clutch
A clutch that uses coil springs to hold the pressure plate against the friction disk.
Coil-Spring Failures
The inability of a coil spring to compress and/or rebound, due to constant overloading, continual jounce and rebound action, metal fatigue, or a crack, break, or nick on the surface layer or coating.
Coil-Spring Rear Suspension
A rear-axle assembly that is attached to the frame through a link-type suspension system. Coil springs are mounted between the lower suspension arms and the frame, while the shock absorbers are mounted between the back of the suspension arms and the frame.
Coil-Spring Seat
The formed mounts that determine the coil-spring position on the car frame and rear axle housing. Seats may have sound-insulating pads.
Coke Bottle
The shape of an auto body tucked slightly inward at the center, like a Coca-Cola bottle.
An acronym for cost of living allowance.
An object that is not hot or warm, generally below body temperature, 98.6°F (37°C).
The absence of all heat, ??259.67aF (??162vC).
Cold Drawn
A process where metal is drawn or rolled into a particular shape or size.
Cold Manifold
An intake manifold that does not have a preheat passage.
Cold Patch
A process used to repair a punctured tire or tube, without the aid of heat.
Cold Rate
The number of minutes a battery will deliver 300 amperes at 0°F (−17.8°C), before the cell voltage drops to below 1.0 volt.
Cold Soak
To place a component in a cool area to allow it to cool to ambient temperature for twelve or more hours.
Cold Weld
A method of repairing small cracks in blocks and heads by using tapered plugs to fill the cracks.
Cold Working
The deformation of metallic material at a temperature below the recrystallization temperature, resulting in strain hardening of the material.
Cold-Cranking Amps
A common term used for cold-cranking power rating.
Cold-Cranking Power Rating
The number of amperes that a fully charged battery will deliver for 30 seconds at 0°F (??17.8tC) without the terminal voltage dropping below 7.2 volts.
Cold-Engine Lockout Switch
A switch that sends a signal to the body-control module, or controller, to prevent an action, such as blower-motor operation, until the coolant in the engine has risen to a predetermined temperature.
Cold-Rolled Steel (CRS)
Carbon steel that is worked into shape while cold.
Cold-Solder Joint
A loose or intermittent electrical connection, caused by poor soldering techniques.
Cold-Start Injector
An electronic fuel-injection system that supplies extra fuel to the engine for cold starting.
Cold-Start Test
A prescribed federal test procedure for measuring emissions before an engine has warmed up after a 12-hour cold soak at 68°F to 78°F (20°C to 25.6°C).
Cold-Start Valve
A valve that permits additional air into the intake manifold during a cold start on a fuel-injected engine.
Cold-Weather Modulator
A thermostatically controlled check valve that traps vacuum in the vacuum motor circuit when the car is accelerated hard at any temperature below 55°F (12.8°C), to prevent hesitation by allowing heated air to enter the engine.
Collapsible Steering Column
An energy-absorbing steering column that is designed to collapse if the driver is thrown into it due to a heavy collision.
A device that collects exhaust gases from the primary tubes and channels them into a single exhaust pipe.
The tank of a radiator that receives the fluid before it passes through the radiator.
Collector Tank
The tank that collects coolant from the engine, containing a baffle plate to aid in even distribution of coolant through the core.
A term used for valve keeper.
Collision Shop
A specialty paint and body shop that restores a wrecked or damaged vehicle to its pre-accident condition.
Color Code
A means of identifying conductors or vacuum hoses by the use of color.
Color Sanding
Color-blending by lightly sanding to smooth surface imperfections, using 1000 grit or higher paper.
Color-Code Chart
A chart listing the colors of wire insulation and, sometimes, wire sizes for a particular automobile.
Combination Brake System
A dual-brake system that uses disc brakes at the front wheels and drum brakes at the rear wheels.
Combination Valve
An H-valve, used in some early air-conditioning systems, combining a suction throttling valve and an expansion valve.
Combined Emissions-control System
An early General Motors transmission-controlled spark system that uses the solenoid valve's plunger as an auxiliary throttle stop.
The burning of the air/fuel mixture in an engine.
Combustion Chamber
Area above a piston at TDC, primarily distinguished by a recessed cylinder head, where combustion takes place.
Combustion Emission Control (CEC)
An exhaust emission-control system that combines a transmission-controlled spark system and a deceleration throttle-position device.
Combustion Knock
A term often used for knock.
Combustion Pressure
The pressure in the cylinder from expanding gases immediately after the air/fuel mixture is ignited, which is about four times greater than compression pressure.
Combustion Recess
An indented area on the rotor face where part of the burning of the air/fuel mixture occurs.
A pleasing and enjoyable feeling due to the removal of excessive heat, moisture, dust, and pollen from the air.
A trade name for an early automatic-temperature-control system.
Common Point
A connection point, such as for several conductors or levers.
Commutating Pole
An electromagnetic bar inserted between the pole pieces of a generator to offset the cross magnetization of the armature currents.
That part of a starter or generator that transfers electrical energy to the armature or rotor.
Compact High-Pressure Tire
A term often used for compact spare.
Compact Spare
A weight- and space-saver tire, especially designed for temporary use.
Compact Spare Tire
A spare tire and wheel that is much smaller than the other tires on the vehicle, and is designed for short-distance driving at relatively low speeds.
Compact Tire
A term used for compact spare tire.
Companion Cylinders
Two cylinders in an engine that are at TDC at the same time.
An instrument for comparing specific critical measurements to a fixed standard.
Compensating Coil
A coil that serves to compensate for the mechanical friction in the moving coil of an electrical meter or gauge.
Compensating Port
A device used to maintain the proper level of brake fluid in the brake lines.
Complete Circuit
An uninterrupted electrical circuit or fluid circuit in which electrical current may travel to and from the battery, or fluid or vapor may circulate continuously through the system.
Completely Built Up (CBU)
The complete building, rebuilding, or modification of a component or vehicle, as in a kit car.
Component Isolation
To isolate a component from the rest of the system or circuit for testing or replacement.
Component Location Table
A table or chart, used with an electrical schematic, that describes or illustrates the actual location of the part being investigated.
Composite Headlight
A halogen headlight system that uses a replaceable bulb, allowing vehicle manufacturers to produce any style of headlight lens they desire.
Composite Materials
The bonding of different materials, usually for strength, such as carbon fiber and fiberglass.
Composite Spring
A term used for fiber-composite spring.
Composite Washer
A flat washer made of different elements.
Composition Gasket
A gasket made of a combination of materials.
Compound Gauge
A gauge that registers both above and below atmospheric pressure; used on the low side of an air-conditioning system.
Compound Low Gear
A combination of low gear in the transmission and low range in the transfer case in a four-wheel-drive vehicle with a two-speed transfer case.
Compressed Natural Gas
A gas, primarily methane, used as a motor fuel.
The process of squeezing a vapor (gas) into a smaller space.
The upward stroke of a piston that compresses the air/fuel mixture into the combustion chamber prior to ignition.
Short for compression ratio.
Compression Braking
The slowing of a vehicle utilizing a diesel engine, such as that provided by a Jake brake. It is a misnomer that a gasoline engine will slow the vehicle by compression braking; actually, vacuum causes the braking effect.
Compression Height
A distance, as measured from the crown of the piston to the center of the wrist pin.
Compression Ignition
The operating system of a diesel engine, where heated air is used to ignite the fuel.
Compression Intake Valve
A term used for compression valve or intake valve.
Compression Pressure
The highest pressure developed during the compression stroke in an engine, as checked with a compression gauge.
Compression Ratio (CR)
A measurement of how much the air/fuel mixture is compressed inside an engine cylinder. If compressed to 1/10 of its original volume, the compression ratio is 10 to 1.
Compression Ring
A piston ring that seals pressure during the compression and power strokes. There are usually two compression rings per piston.
Compression Seal
A metal seal found in a direct fuel-injection system, to resist compression pressures.
Compression Stroke
The movement of the piston from BDC to TDC, immediately after the intake stroke.
Compression Valve
A calibrated valve, located at the base of the shock absorber, providing variable resistance to fluid flow during compression.
Compression-Loaded Ball Joint
A suspension ball joint, mounted above and resting on the knuckle, so the vehicle weight forces the ball into the joint.
Compressive Strength
The maximum compressive stress that a material can withstand without significant plastic deformation or fracture.
A component of the refrigeration system that pumps refrigerant and increases the pressure of the refrigerant vapor.
A device used to pump air.
Compressor Crankshaft Seal
A term used for compressor shaft seal.
Compressor-Discharge Pressure switch
A pressure-operated electrical switch that opens the compressor-clutch circuit during high-pressure conditions.
Compressor-Protection Switch
An electrical switch installed in the rear head of some compressors to stop the compressor in the event of a loss of refrigerant.
Compressor-Shaft Seal
An assembly consisting of springs, snap rings, O-rings, seal sets, a shaft seal, and a gasket mounted on the compressor crankshaft to permit the shaft to be turned without a loss of refrigerant or oil.
A machine capable of following instructions to alter data in a desirable way and to perform most of these operations without human intervention.
Computer-Aided Manufacturing
The use of computer technology in the management, control, and operation of manufacturing.
Computer-Command Control (CCC)
A term given a computer that controls the function and operation of an automotive system, or sub system.
Computer-Controlled Brakes
A system having a sensor on each wheel, feeding electrical impulses into an on-board computer. As the vehicle is stopped, each wheel is stopped or slowed down at the same rate, reducing sideways skidding during rapid braking.
Computer-Controlled Suspension System
A system in which a computer-controlled actuator is positioned in the top of each shock absorber or strut. The shock absorber or strut actuators rotate a shaft inside the piston rod, and this shaft is connected to the shock valve.
Computer-Generated Code
A term more commonly known as trouble code.
The jargon and other specialized vocabulary of those working with computers and information-processing systems.
To equip a business or organization with computers in order to facilitate or automate procedures.
To convert a manual operation into one that is performed by a computer.
Computerized Air Suspension
A type of suspension system equipped with rubber air bags controlled by an air compressor to maintain a specific ride height determined by vehicle load and road-surface conditions.
Computerized Automatic Temperature Control
A microprocessor control system that monitors incoming data and adjusts the temperature and humidity of the air inside the passenger compartment.
Computerized Engine Control
A microprocessor-based, engine-management system that utilizes various sensor inputs to regulate spark timing, fuel mixture, emissions, and other functions. Most systems include on-board, self-diagnostic capability and store fault codes to help diagnosis of system problems.
Con Rod
Short for connecting rod.
Concave Fillet Weld
A fillet weld having a concave face.
Concave Side
An inward-curved depression.
Concealed Headlight
A headlight system that enhances a vehicle's style and aerodynamics by hiding the lamps behind electrically- or vacuum-controlled doors when not in use.
The condition in which two or more features, in any combination, have a common axis.
Concours D'Elegance
French for contest of elegance, a showing of luxury cars in a plush setting.
Moisture that is removed from air, such as that collected on the surface of an air-conditioning-system evaporator.
The moisture removed from ambient air.
The process of a substance changing state from a vapor (gas) to a liquid.
A liquefier; the component of a refrigeration system in which refrigerant vapor is changed to a liquid by the removal of heat.
An improper but often used term for a capacitor.
Condenser Comb
A comb-like device used to straighten the fins on the evaporator or condenser.
Condenser Temperature
The temperature at which compressed gas in the condenser changes to a liquid.
Condensing Pressure
High side or head pressure, as read from the gauge at the high-side service valve.
The pressure present from the discharge side of the compressor to the metering device inlet.
Conditioned Air
Air that is cool, dry, and clean.
The ability of a material to transmit an electrical charge.
Any material that will conduct an electrical charge, such as a copper wire.
Conductor Placement
A term used for wire placement.
A tubular raceway, such as tubing used to protect a wiring system or branch circuit.
The conical Diaphragm attached to the voice coil of a speaker that produces sound.
The conical part of an oxyfuel gas flame adjacent to the tip orifice.
Coned-Disk Spring
A term used for Belleville washer.
The shape or form of anything, such as an engine.
The ease or difficulty of different materials to be shaped or worked.
A term that refers to tire conicity.
Connecting Link
A link in which a removable plate facilitates connecting or disconnecting the ends of a length of chain.
Connecting Rod
A component used to attach the piston, with pin, to the crankshaft rod journal.
Connecting-Rod Cap
The half-round, lower, bolt-on portion of the connecting rod.
Constant Mesh
Gears that mesh continually, such as a planetary gear, eliminating the clashing or grinding that may occur when other types of gears are shifted together.
Constant Tension
A system or device that is designed to be under perpetual pressure or stress.
Constant Voltage
The common type of power in which all loads are connected in parallel, with different amounts of current flowing through each load.
Constant-Current Charging
A charging system in which a constant flow of current is fed into the battery.
Constant-Current Electronic Control (CCEC)
A type of engine-computer control.
Constant-Ratio Steering Gear
A steering-gear system having the same gear ratio when the wheels are near the straight-ahead position as during extreme turns.
Constant-Velocity Joint
Two universal joints, closely coupled, so their acceleration-deceleration effects cancel each other out.
Constant-Voltage Charging
A method of charging where the voltage to the battery is constant, and the current decreases as a fully-charged condition is reached.
A term most generally used when referring to fuel consumption.
Contact Area
The area of a member that comes into contact with another member, such as a belt to a pulley, or a tire to the ground.
Contact Patch
The area of contact of a tire with the road surface when the tire is supporting the vehicle weight.
Contact Points
A term often used for contact area or breaker points.
Container Tube
A shock-absorber component that is used to house the internal parts.
Chemicals or impurities in oil or fuel that reduce its effectiveness and efficiency, such as water, carbon, acids, dust, and dirt particles.
Chemicals or impurities that make ambient air impure, especially those produced from the combustion process.
A term used when referring to a system that is known to contain foreign substances, such as incompatible or hazardous materials.
Contingency Money
A payment made by accessory and equipment manufacturers to top rated drivers, and some crew members, for using and/or displaying their products in a race.
The ease or ability of an electrical circuit to transfer energy from one point to another.
Continuous Code
A series of computer diagnostic codes that relate to engine-control functions.
Continuous Combustion
The constant combustion of an air/fuel mixture.
Continuous Duty
A demand on an energy-consuming system that requires operation, at a constant load, for an indefinite period of time.
Continuous Fuel Injection (CFI)
A type of fuel-injection system that continuously sprays a stream of fuel into the engine.
Continuous Variable Transmission (CTV)
A stepless transmission that uses a sheave clutch to transmit engine torque.
Continuous Weld
A weld that extends continuously from one end of a joint to the other.
Continuous-Injection System (CIS)
A continuous-flow, mechanically controlled, fuel-injection system.
Continuous-Injection System--Electronic (CIS-E)
A continuous-flow, electronically controlled, fuel-injection system.
Control Arm
The main link between the vehicle frame and the wheels that acts as a hinge to allow the wheels to go up and down independently of the chassis.
Control Cable
A rigid wire, generally sheathed, used for the remote control of a device, such as a parking brake.
An insulated wire used to supply electric current to a motor, controls, or other electrically operated circuits or devices.
Control Head
The master controls (such as temperature and fan speed) that the vehicle driver uses to select the desired system condition.
Control Link
A term used for control arm.
Control Plunger
A device that is regulated by the fuel-injection-system airflow sensor to regulate fuel delivery to the injectors.
Control Points
Holes, points, or flat surfaces that are used to align body parts during assembly or reconstruction.
Control Pressure
The fuel pressure required for a fuel-injection system to function.
Control Valve
The mechanism, located inside the power steering gearbox or on the steering relay rod, that controls the amount of power assist relayed to the steering linkage via a power piston.
Controlled-Leak Governor
A governor assembly that reduces the leakage of line pressure as a vehicle's speed increases.
The transfer of heat by motion of the heated material, such as air.
Conventional Cab
A truck having a cab behind the engine.
Conventional Frame
A chassis frame that is separate from the body.
Conventional Strut
An assembly in which the coil spring that supports the vehicle weight sits on a lower-spring seat, which is part of the strut housing, to maintain vehicle height.
Conventional Theory
That electrons flow from the positive to the negative point in an automotive electrical system. Actually, flow is from negative to positive.
Conventional Tire
A term used for bias ply tire.
Conventional-Frame Designs
One of three designs: Ladder frame; x-frame, or hourglass frame; or, perimeter frame.
The substitution of one element or component for another, as in substituting R-134a for R-12 in an automotive air-conditioning system; changing the fuel-type requirements of an engine; or changing ignition systems.
Converter Dolly
An axle, frame, drawbar, and fifth-wheel arrangement that converts a semi-trailer into a full trailer.
Converter Pressure
The operating pressure within the torque converter.
Converter-Signal Pressure
The pressure that signals the torque-converter, lockup clutch engagement.
An automobile having a retractable or removable roof.
Convertible Top
A vinyl or canvas soft-top roof system for two- or four-door vehicles that can be manually or automatically lowered and raised.
To overheat, generally to the point of severe or irreparable damage.
To perform well, as in s/he's cookin'.
Cool Pack
A trade name used to describe an early after-market hang-on or under-dash, after-market air-conditioning system.
The fluid, consisting of water and antifreeze, that circulates throughout a liquid-cooling system, around hot engine parts, to remove the heat and prevent damage.
Coolant Circulation
The movement of liquid throughout the cooling system by water pump action to move heat, generated by engine combustion, to the upper radiator section.
Coolant Fan
An electrically- or mechanically-driven fan to increase air flow across the radiator to facilitate heat removal.
Coolant Jacket
Hollow passages surrounding the cylinders in the block and the combustion chambers in the cylinder head.
Coolant Passages
Coolant passages, called coolant jackets or water jackets, surround each cylinder in the block to provide a means to carry away unwanted engine heat.
Coolant Pump
A term often used for water pump. A centrifugal-type pump used to circulate coolant through the cooling system.
Coolant Reservoir
A tank used for storing excess coolant; connected to the cooling system with a small-diameter overflow hose.
Coolant Temperature-Override Switch
A temperature-controlled vacuum device that prevents overheating during idle speed, associated with late ignition, by advancing the timing to increase engine-idle speed.
Coolant Thermostat
A unit found in the coolant outlet of the engine to help prevent over-cooling conditions, especially during short trips.
Coolant-Fan Relay
A control device that is used to activate the electric-coolant fan at a pre-determined, high-coolant temperature.
Coolant-Recovery System
A cooling system having a semisealed pressure cap, with a radiator-overflow hose leading into a separate plastic reservoir. This saves coolant during hot operation and returns it to the radiator when the system cools.
Coolant-Recovery Tank
A storage container that is used in a coolant-recovery system.
Coolant-Temperature Sensor
A thermistor that sends a signal to the electronic control unit relative to the coolant temperature in a computerized engine-control system.
Cooling Coil
An evaporator.
An oil cooler.
An auxiliary cooler.
Cooling Method
The method used to remove excess heat from an engine or system, such as air cooling or liquid cooling.
Cooling System
An air conditioner.
A system of parts that circulates coolant through the engine to remove heat.
A system to remove heat from a heat-generating mechanism.
Cooling-Fan Controller Module
An electronic unit that will cycle the cooling fan ON and OFF, in response to signals from other engine sensors.
Cooling-System Fan
An electrically- or mechanically-driven rotating device, having four to seven pitched blades to move air past a heat exchanger, such as the radiator.
Copper (Cu)
A reddish-colored metallic element, with great electrical properties; one of the oldest metals known.
Copper Gasket
A gasket made of copper and used in high-temperature and pressure conditions.
Copper Sulfate
A chemical used to detect chrome-plated cylinders and test crankshafts for Tuftriding.
Copper-Asbestos-Copper Gasket
A gasket made of copper-clad asbestos; now rare and not used due to the dangers associated with asbestos fibers.
An inner material of textile, steel, fiberglass, or wire running through the plies of a tire that produce strength.
Cord Material
A material, such as rayon, nylon, fiberglass, polyester, or steel, used in tire construction to provide strength and maintain desired shape.
Cord Plies
The layers of rubber-impregnated cord material molded in the sidewalls of the tire casing.
The interior of a hollow casing.
The coolant passages and fins of a radiator or heater found between the two header tanks.
A used part or assembly that is to be returned to the vendor for rebuilding.
Core Hole
A hole provided to facilitate sand casting.
A cavity in a casting caused by the shifting of the core during manufacturing.
Core Loss
The electric loss occurring in the core of an armature or transformer due to eddy currents, hysteresis, and like influences.
Core Plug
A metal, cup-shaped disc in a cast component, such as the engine block, to seal openings required by the casting tools that may pop out to protect it from freezing damage. Also known as freeze plug.
Core Shift
A condition where one side of a cylinder bore is thicker than the other side.
Core-Hole Plug
A plug used to provide a seal for a core hole.
Cornering Light
Lamps in both sides of the vehicle body near the front that light up when the turn signals are activated and burn steady when the turn signal switch is in a turn position, providing additional illumination of the road in the direction of the turn.
Corporate Average Fuel Economy (CAFE)
The fuel mileage standard for an automaker's line of vehicles set annually by the Department of Transportation (DOT).
Corrosive Flux
A flux composed of inorganic salts and acids, organic salts and acids, or activated rosin with a residue that chemically attacks the base metal.
Corrosive Rain
A form of pollution produced when sulfur and nitrogen are emitted into the air. Known as acid rain.
Corrugated Metal Gasket
Thin sheets of metal used as a gasket that is shaped into parallel grooves and ridges for added strength.
Italian for course.
An abbreviation for Carwash Owners and Suppliers Association, Inc.
A trade name for a heavy-grade lubricant used to protect machine surfaces.
Cost of Living Allowance (COLA)
An increase in stipends based on the average increase in the cost of living for any given period.
A British racing-engine manufacturer.
To damage or destroy an engine.
A device, such as a register or computer-storage location, used to represent the number of occurrences of an event.
Counter EMF
Induced voltage; the voltage opposing the applied voltage and the current in a coil, caused by a flow of current in the coil.
A weight added to a rotating shaft or wheel to offset vibrations.
Counterbored Ring
A compression piston ring with a counterbore on its inside diameter to promote cylinder sealing.
A machining process, related to drilling, using an end-cutting tool to concentrically enlarge a hole to a limited depth.
Counterclockwise (ccw)
A rotation to the left; as opposed to the direction of the rotation of clock hands.
Counterclockwise Rotation
Rotating in the opposite direction of the hands on a clock.
Counterelectromotive Force
A term used for back emf or counter emf.
An integral cluster of three or more various-sized gears, located in the lower transmission case, that revolve on a countershaft to provide the desired gear ratios, usually for second, low, and reverse.
A shaft used in a V-8 engine to reduce the effects of imbalance.
Two shafts used in an I-4 engine to reduce the effects of imbalance.
The shaft that supports the cluster-gear set in a manual transmission and rotates in the opposite direction of the clutch and driveshaft.
A machining process, related to drilling, that bevels or recesses the material around the circumference of a hole.
A weight that is cast opposite each offset connecting-rod journal to provide the necessary balance.
A weight that is added to a rotating shaft or member to offset vibration by balancing the part.
Coupe (CPE)
A car with a close-coupled passenger compartment.
Coupe De Ville
A coupe with an open driver compartment and enclosed passenger compartment.
An attachment where one mechanism or part drives another mechanism or part, to follow the movements of the first.
Coupling Phase
The point in torque-converter operation where the turbine speed is 90% of the impeller speed, and there is no longer any torque multiplication.
Coupling Stage
A term referring to the torque-converter turbine speed, as it closely approaches the impeller speed; occurs during higher speeds under light loads.
Coupling Yoke
Two integral or separate Y-shaped components to which the universal-joint bearing cups are attached.
A piece of metal, of specified size, used for testing.
A piece of metal from which a test specimen may be prepared.
Courtesy Light
Lamps that illuminate the vehicle interior and/or exterior when a door is opened, and are controlled from the headlight and door switches.
Covered Electrode
A composite filler metal consisting of a core of bare electrodes or a metal-cored electrode, with a covering sufficient to provide a slag layer on the weld metal.
That part of a vehicle between the passenger compartment and engine to which the windshield and dashboard are attached.
Cowl Air Intake
The inlet at the base of the windshield that allows outside air to enter the heater/air-conditioning system, or driver/passenger compartment of the vehicle.
An abbreviation for centipoise.
An abbreviation for coupe.
An abbreviation for central processing unit.
An abbreviation for compression ratio.
A term often used for the mid-position of a two-way valve.
A crankshaft.
To start an engine.
To go fast.
Crank Kit
A reconditioned crankshaft with the appropriate rod and main bearings.
Crank Pin
The rod journal of a crankshaft.
Crank RPM
A measurement that is required for an electronic engine-control system to determine when ignition should occur.
Crank Signal
An electrical signal sent to the computer to tell it that the engine is cranking and to enrich the air/fuel ratio for easier starting.
Crank start
To start an internal-combustion engine by hand cranking.
Crank Web
That part of a crankshaft that is between a crankpin and a main bearing.
The lower section of the engine that supports the crankshaft, confined by the lower block casting and the oil pan.
Crankcase Breather
A tube or vent that allows excessive crankcase pressure to escape.
Crankcase Dilution
The thinning of oil in the crankcase, caused by the condensation of gasoline due to blow-by, and by seepage past the piston rings.
Crankcase Emissions
Fumes that leave the crankcase by way of an open or closed ventilation system.
Crankcase Fumes
Vapors inside the crankcase that could contaminate the air, including unburned fuel vapors, water vapor, or blow-by gases. Also known as crankcase vapors.
Crankcase Pressure
The pressure produced in the crankcase from blow-by gases.
Crankcase Vapors
Fumes inside the crankcase, caused by blow-by, that could contaminate the air, including unburned fuel vapors, water vapor, or blow-by gases. Also known as crankcase fumes.
Crankcase Ventilation
A tube or vent that allows excessive crankcase pressure to escape.
Cranking Circuit
The starter and its associated circuit, including battery, relay (solenoid), ignition switch, neutral start switch, cables, and wires.
Cranking Motor
A special high-torque electric motor designed for the purpose of cranking the engine for starting.
A revolving part mounted in the lower portion of the engine block.
That part of a reciprocating compressor on which the wobble plate or connecting rods are attached.
Crankshaft Arm
A connector between the two rod journals and the main bearing on the crankshaft.
Crankshaft Counterbalance
A term used for crankcase counterweight.
Crankshaft Counterweight
A weight that is cast opposite each offset connecting-rod journal, to provide the necessary balance.
Crankshaft End-Play
A specified crankshaft endwise motion controlled by side flanges on one of the main bearings.
Crankshaft Gear
A gear or sprocket found on the front end of the crankshaft that is used, directly or indirectly, to drive the camshaft.
Crankshaft Main Journal
That part of the crankshaft, ground round and polished smooth, around which the closely-fitted main bearings surround the journals and support the crankshaft.
Crankshaft Oil Passage
Holes drilled through the crankshaft to permit oil to flow from the main bearings to the connecting-rod bearings.
Crankshaft Pulley
A pulley fitting on the front of the crankshaft.
Crankshaft Seal
A rubber-like seal around an engine crankshaft to prevent the leakage of oil.
A rubber-like and/or ceramic seal surrounding the compressor crankshaft to prevent the leakage of oil and/or refrigerant.
Crankshaft Throw
One crankpin with two webs.
Crankshaft Thrust Collar
A disc-shaped, machined surface between the main bearing and the two rod journals on the crankshaft.
Crash Box
A manual transmission with straight-cut, non-synchromesh gears.
Crash Sensor
Normally open, gold-plated, electrical switches that are designed to close when subjected to a predetermined impact.
Fine cracks that may extend in a network on or under the surface of a material, often occurring in the presence of an organic liquid or vapor.
Cream Hardener
An activating ingredient for a plastic-filler material, such as Bondo.
Cream Puff
A vehicle that is in especially fine condition.
Creature Comforts
Any options or amenities that improve vehicle driving or riding pleasures.
A concave and convex shape.
A short roadway curved in a half circle.
Critical Pressure
The pressure at which a gas becomes unstable.
Critical Temperature
The temperature at which a flammable gas will ignite.
Crocus Cloth
A very fine-grit sandpaper that is used to clean or polish parts, such as a crankcase.
The central component of the U-joint connecting the input and output yokes.
Cross Heads
A T-shaped part on a diesel engine to open and close two valves at one time.
Cross Lock
A holding device used with automatic-throttle cable adjusters.
Cross Section
A section formed by a plane cutting through an object, generally at 90° to the centerline to show interior details in a the centerline to show interior details in a drawing.
Cross Up
To lose control of a vehicle, allowing it to spin or skid out of control.
Cross-Drilled Crank
A crankshaft having two oil passages at right angles to each other in the main journal to provide extra lubrication for the main and rod bearings.
Cross-Groove Joint
A disc-shaped, inner, constant-velocity universal joint that bolts to a transaxle stub flange and uses balls and V-shaped grooves on the inner and outer races to accommodate the plunging motion of the half-shaft.
Crossbolt Main Cap
A main-bearing cap that is secured with two down-facing bolts and two bolts that intersect at right angles.
The electromagnetic-induction spark that can be transmitted in another wire close to the wire carrying the current.
Crossfire Injection
A type of throttle-body injection system that uses two injectors mounted on the manifold. Each injector feeds a cylinder on the opposite side by using a crossover port.
Crossflow Head
A cylinder head having its intake ports on one side and the exhaust ports on the other side.
Crossflow Radiator
A radiator in which the coolant flow is from one side to the other.
A honing pattern that is required in a cylinder to maintain the correct amount of oil retention and to facilitate ring rotation.
A series of crisscrossing lines that indicate a specific area in a drawing or diagram.
Crossover Network
An electrical circuit that routes different frequencies to the woofer, midrange, and tweeter in a multiple-speaker system.
Crossover Pipe
A pipe used to connect both sides of an exhaust system to equalize the pressure.
Crossover Tube
A tube that is used to transmit liquid or gases in or around an engine.
Crotch Height
The height of a chain-link crotch above the pitch line of the link.
An accelerator action that maintains a constant manifold-vacuum reading, requiring a progressive opening of the throttle as the vehicle speed is increased.
The top surface of a piston.
Crown Gear
The ring gear in a differential.
Crown Wheel
A term often used for crown gear.
An abbreviation for cold-rolled steel.
An abbreviation for cathode-ray tube.
Crude Oil
Petroleum in its natural state; as pumped from the ground before refinement.
Cruise Control
A control system that allows the vehicle to maintain a preset speed, though the driver's foot is off the accelerator.
A motorized version of a Saturday evening promenade around the town square.
A social outing, generally by young people, driving a route repeatedly on the major city streets at a slow speed, often for hours at a time.
A chance for young men, or ladies, to show off their wheels and flirt with the young ladies, or men.
Crunch Hat
A safety helmet.
The amount of compression required to seat a rod or main bearing into its housing bore.
Crush Relief
The area at the edge of a rod, or main bearing, that allows the crush to occur.
Crush Sleeve
A sleeve that is used to position a pinion gear in the differential; designed to crush when torqued to specifications.
An abbreviation for centistroke.
An abbreviation for coolant temperature override.
Symbol for copper.
A term for cubic-inch displacement or CID.
Cubic Feet Per Minute
The measure of a carburetor's air-flow capacity.
Cubic Inch (ci)
An English measure for volume equal to 16.39 ccs.
Cubic-Inch Displacement (CID)
The English measure for the volume of space displaced by the piston as it moves from BDC to TDC.
Cup Expander
Metal discs formed to fit inside piston cups and to keep the lips of the cups in tight contact with the cylinder walls while the hydraulic system is not pressurized.
Cup Seal
The rubber seal inside a wheel cylinder.
Cup Shim
A cup-shaped spring adjuster used to reduce valve-spring bounce at high engine rpm.
Cup Wheel
A wheel shaped like a cup or bowl.
Curb Height
The measurement from the vehicle frame to the road surface.
Curb Weight
The weight of a vehicle ready for the road, with a full complement of fuel, oil, and coolant, but without cargo, driver, or passengers.
The right-hand side of a vehicle; that nearest to the curb.
The hardening of a catalyzed compound, such as fiberglass.
The drying of paint.
At present. Now.
Rate of flow of electric charge through a conductor.
Current-Carrying Capacity
The current, in amperes, a conductor can carry continuously, under the conditions of use, without exceeding its temperature rating.
Current-Draw Test
Starting-system test that determines amperes consumed by the starter motor during operation.
A position indicator on a video display to indicate data or a command to be corrected, repositioned, or entered.
Curtain Area
An engineering term that relates to the efficiency of the flow of air and fuel entering the combustion chamber.
Curved Washer
A spring-type washer that exerts a relatively light thrust load and is used to absorb axial-end play.
A car that has been restyled for a distinctive appearance.
Custom System
A proprietary system built to exact specifications.
An early model, deluxe, automotive air-conditioning system that used both inside and outside air.
Customary Measurements
United States customary measurements; the English measuring system of inches, feet, yards, miles, and so on.
To restyle a vehicle.
To defeat or eliminate a competitor in a drag race.
To sever.
The direction and texture of the cutting teeth of a file.
Cut a Big One
To record a particularly high speed or fast time. Also referred to as cut a fat one.
Cut a Fat One
Same as cut a big one.
To experience a momentary engine miss without a stall.
A fuse holder that may be used to isolate part of a circuit.
To bypass the exhaust system.
Cutout Relay
An electrical, protective ON and OFF switch between the generator and battery.
Cutting Attachment
A device for converting an oxyfuel-gas welding torch into an oxygen cutting torch.
Cutting Brake
A special type of master cylinder with two brake levers to control how much brake pressure is applied to either of the rear wheels, allowing an off-road vehicle to make a much sharper turn.
Cutting Fluid
Any fluid applied to a cutter or to work being cut, to aid in the cutting operation by cooling and lubricating.
Cutting Tip
The part of a cutting torch from which the gases are emitted.
CV Joint
A shortened version of constant velocity joint.
An abbreviation for Compound Vortex Combustion Control.
An abbreviation for continuously variable transmission.
An abbreviation for clockwise.
An abbreviation for cargo weight ratio.
Symbol for coefficient of drag.
The process of discharging and then recharging a battery.
A series of repeated events such as the intake, compression, power, and exhaust strokes of an engine.
A complete series of events.
Short for motorcycle.
Cycle Clutch Time
The time from the moment the clutch engages until it disengages, then re-engages. Total time is equal to ON time, plus OFF time for one cycle.
Cycle Fenders
Individual fenders for each wheel of a car.
Cycling Clutch
An air-conditioning, electro-magnetic clutch that is turned on and off to control cabin temperature.
Cycling-Clutch Fixed Orifice Tube (CCFOT)
An air-conditioning system having a fixed-orifice tube in which the air temperature is controlled by starting and stopping the compressor with a thermostat or pressure compressor with a thermostat or pressure control.
Cycling-Clutch Orifice Tube
A term often used for cycling-clutch, fixed-orifice tube.
Cycling-Clutch System
An air-conditioning system in which the cabin air temperature is controlled by starting and stopping the compressor with a thermostat or pressure control.
A gasket made of treated asbestos layers bonded to a metal plate; now obsolete due to personal and environmental hazards associated with asbestos.
A storage tank for gases, such as refrigerant.
The round hole(s) inside an engine block that provide space for the reciprocating piston(s).
Cylinder Arrangement
The way cylinders are placed in an engine, such as in-line, in a row; vee, in two banks or rows at an angle to each other; or flat, pancake.
Cylinder Block
The basic framework of an engine to which all other parts and assemblies are installed or attached.
Cylinder Bore
The diameter of a cylinder.
Cylinder Combustion Pressure
The pressure in the cylinder from expanding gases immediately after the air/fuel mixture is ignited; about four times greater than compression pressure.
Cylinder Deglazing
The process of removing the glaze from cylinder walls after extended use.
Cylinder Head
That part of the engine that covers the cylinders and pistons.
Cylinder Liner
A replaceable cylinder wall.
Cylinder Numbering
The order in which the cylinders are numbered cylinder one may be on either front side of a V engine and start with one at the front of in-line engines.
Cylinder Sleeve
A round, replaceable, cylindrical tube that fits into the cylinder bore.
Cylinder-Head Gasket
The gasket used to seal the head to the block to promote compression and to ensure a leak-free bond.