Automotive Glossary of Terms - C -
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Definitions for automotive terms and illustrations from california engine to cylinder.
CALIFORNIA ENGINE
An engine certified by the EPA for use in California only; conforms to more stringent emission regulations than Federal engine.
CALIPER
A hydraulically activated device in a disc brake system, which is mounted straddling the brake rotor (disc). The caliper contains at least one piston and two brake pads. Hydraulic pressure on the piston (s) forces the pads against the rotor.
CAMBER
One of the factors of wheel alignment. Viewed from the front of the car, it is the inward or outward tilt of the wheel. The top of the tire will lean outward (positive camber) or inward (negative camber).
CAMSHAFT
A shaft in the engine on which are the lobes (cams) which operate the valves. The camshaft is driven by the crankshaft, via a belt, chain or gears, at one half the crankshaft speed.
CAR CANCER
Rust on a car body.
CAPACITOR
A device which stores an electrical charge.
CARBON MONOXIDE (CO)
A colorless, odorless gas given off as a normal byproduct of combustion. It is poisonous and extremely dangerous in confined areas, building up slowly to toxic levels without warning if adequate ventilation is not available.
CARBURETOR
A device, usually mounted on the intake manifold of an engine, which mixes the air and fuel in the proper proportion to allow even combustion.
CASTER
The forward or rearward tilt of an imaginary line drawn through the upper ball joint and the center of the wheel. Viewed from the sides, positive caster (forward tilt) lends directional stability, while negative caster (rearward tilt) produces instability.
CATALYTIC CONVERTER
A device installed in the exhaust system, like a muffler, that converts harmful byproducts of combustion into carbon dioxide and water vapor by means of a heat-producing chemical reaction.
CENTRIFUGAL ADVANCE
A mechanical method of advancing the spark timing by using flyweights in the distributor that react to centrifugal force generated by the distributor shaft rotation.
CETANE RATING
A measure of the ignition value of diesel fuel. The higher the cetane rating, the better the fuel. Diesel fuel cetane rating is roughly comparable to gasoline octane rating.
CHECK ENGINE LIGHT
The malfunction indicator light that the vehicle's on board computer illuminates when it senses a fault in a monitored system.
CHECK VALVE
Any one-way valve installed to permit the flow of air, fuel or vacuum in one direction only.
CHOKE VALVE
The valve/plate that restricts the amount of air entering an engine on the induction stroke, thereby enriching the air:fuel ratio.
CIRCLIP:A split steel snap ring that fits into a groove to hold various parts in place.
CIRCUIT BREAKER
A switch which protects an electrical circuit from overload by opening the circuit when the current flow exceeds a pre-determined level. Some circuit breakers must be reset manually, while most reset automatically.
CIRCUIT
Any unbroken path through which an electrical current can flow. Also used to describe fuel flow in some instances.
CLEARCOAT
A transparent layer which, when sprayed over a car's paint service, adds gloss and depth as well as an additional protective coating to the finish.
CLUTCH
Part of the power train used to connect/disconnect power to the rear wheels.
COIL
Part of the ignition system that boosts the relatively low voltage supplied by the car's electrical system to the high voltage required to fire the spark plugs.
COMBINATION MANIFOLD
An assembly which includes both the intake and exhaust manifolds in one casting.
COMBINATION VALVE
A device used in some fuel systems that routes fuel vapors to a charcoal storage canister instead of venting them into the atmosphere. The valve relieves fuel tank pressure and allows fresh air into the tank as the fuel level drops to prevent a vapor lock situation.
COMBUSTION CHAMBER
The part of the engine in the cylinder head where combustion takes place.
COMPRESSION CHECK
A test involving removing each spark plug and inserting a gauge. When the engine is cranked, the gauge will record a pressure reading in the individual cylinder. General operating condition can be determined from a compression check.
COMPRESSION RATIO
The ratio of the volume between the piston and cylinder head when the piston is at the bottom of its stroke (bottom dead center) and when the piston is at the top of its stroke (top dead center).
CONDENSER
1. An electrical device which acts to store an electrical charge, preventing voltage surges. 2. A radiator-like device in the air conditioning system in which refrigerant gas condenses into a liquid, giving off heat.
CONDUCTOR
Any material through which an electrical current can be transmitted easily.
CONNECTING ROD
The connecting link between the crankshaft and piston.
CONSTANT VELOCITY JOINT
Type of universal joint in a halfshaft assembly in which the output shaft turns at a constant angular velocity without variation, provided that the speed of the input shaft is constant.
CONTINUITY
Continuous or complete circuit. Can be checked with an ohmmeter.
CONTROL ARM
The upper or lower suspension components which are mounted on the frame and support the ball joints and steering knuckles.
CONVENTIONAL IGNITION
Ignition system which uses breaker points.
COOLANT
Mixture of water and anti-freeze circulated through the engine to carry off heat produced by the engine.
COUNTERSHAFT
An intermediate shaft which is rotated by a mainshaft and transmits, in turn, that rotation to a working part.
CRANKCASE
The lower part of an engine in which the crankshaft and related parts operate.
CRANKSHAFT
Engine component (connected to pistons by connecting rods) which converts the reciprocating (up and down) motion of pistons to rotary motion used to turn the driveshaft.CURB WEIGHT
The weight of a car without passengers or payload, but including all fluids (oil, gas, coolant, etc.) and other equipment specified as standard.
CV-JOINT
Constant velocity joint.
CYLINDER BLOCK
See engine block.
CYLINDER HEAD
The detachable portion of the engine, usually fastened to the top of the cylinder block and containing all or most of the combustion chambers. On overhead valve engines, it contains the valves and their operating parts. On overhead cam engines, it contains the camshaft as well.
CYLINDER
In an engine, the round hole in the engine block in which the piston(s) ride.