Dictionary of Automotive Terms: E

EARTH (Electrical): British term for ground.

EARTH WIRE: British term for ground wire.

ECCENTRIC (Off Center): Two circles, one within the other, neither sharing the same center. A protrusion on a shaft that rubs against or is connected to another part.

ECONOMIZER VALVE: Fuel flow control device within carburetor.

EEC: Evaporative Emission Control.

EGR: Exhaust Gas Recirculation.

ELECTRIC ASSIST CHOKE: A choke utilizing an electric heating unit to speed up its opening time.

ELECTRIC FUEL PUMP: Fuel pump operated by electricity and electric motor. Normally mounted in or near fuel tank.

ELECTROCHEMICAL: Chemical (battery) production of electricity.

ELECTRODE (Spark Plug): Center rod passing through insulator forms one electrode. The rod welded to shell forms another. They are referred to as center and side electrodes. ELECTRODE (Welding): Metal rod used in arc welding.

ELECTROLYTE: Sulfuric acid and water solution in battery.

ELECTROMAGNET: Magnet produced by placing coil of wire around steel or iron bar. When current flows through coil, bar becomes magnetized and will remain so as long as current continues to flow.

ELECTROMAGNETIC: Magnetic (generator) production of electricity.

ELECTRON: Negatively charged particle that makes up part of the atom.

ELECTRON THEORY: Accepted theory that electricity is flow of electrons from one area to another.

ELECTRONIC: Refers to electrical circuits or units employing transistors, magnetic amplifiers, computers, etc.

ELECTRONIC FUEL INJECTION: An electric solenoid type injector, engine sensors, computer, etc., used to control fuel spray into engine.

ELECTRONIC IGNITION: Ignition system with no conventional breaker points. Primary circuit is broken by magnetic pickup and electronic control unit.

ELECTROPLATE: Process of depositing gold, silver, chrome, nickel, etc., upon an object by placing object in special solution and then passing an electric current through solution. Object forms one terminal, special electrode the other. Direct current is used.

ELEMENT ( Battery): Group of plates. Three elements for a six volt and six elements for the twelve volt battery. The elements are connected in series.

ELLIOT TYPE AXLE: Solid bar front axle on which ends span or straddle steering knuckle.

EMF: Electromotive force. (Voltage.)

EMISSIONS: By-products of automotive engine combustion that are discharged into atmosphere. Major pollutants are oxides of nitrogen, carbon monoxide, hydrocarbons, and various particulates. Term also includes vapor (hydrocarbon) loss from fuel tank and carburetor.

END PLAY: Amount of axial (lengthwise) movement between two parts.

ENERGY (Physics): Capacity for doing work.

ENGINE ADAPTER: Unit that allows a different engine to be installed in a car—and still bolt up to original transmission.

ENGINE (Auto): Device that converts heat energy into useful mechanical motion.

ENGINE DISPLACEMENT (Size): Volume of space through which head of piston moves in full length of its stroke — multiplied by number of cylinders in engine. Result is given in cubic inches.

ENGINE MOUNTS: Pads made of metal and rubber which hold engine to frame.

EP LUBRICANT (Extreme Pressure): Lubricant compounded to withstand very heavy loads imposed on gear teeth.

EPA: Environmental Protection Agency. This is a Federal agency.

ESC: Electronic Spark Control.

ETHYL GASOLINE: Gasoline to which Ethyl fluid has been added to improve gasoline’s resistance to knocking. Slows down burning rate thereby creating a smooth pressure curve that will allow the gasoline to be used in high compression engines.

ETHYLENE GLYCOL: Chemical solution added to cooling system to protect against freezing.

EVAPORATION: Process of a liquid turning into a vapor.

EVAPORATION CONTROL SYSTEM: Emission control system designed to prevent gasoline vapors from escaping into atmosphere from tank and carburetor.

EVAPORATOR: Unit in air conditioning system used to transform refrigerant from a liquid to a gas. It is at this point that cooling takes place.

EXCITE: To pass an electric current through a unit such as field coils in generator.

EXHAUST CUTOUT: Y-shaped device placed in exhaust pipe ahead of muffler. Driver may channel exhaust through muffler or out other leg of the Y where exhaust passes out without going through the muffler.

EXHAUST GAS ANALYZER: Instrument used to check exhaust gases to determine combustion efficiency.

EXHAUST GAS RECIRCULATION: Admitting a controlled amount of exhaust gas into intake manifold during certain periods of engine operation. This lowers combustion flame temperature, thus reducing level of nitrogen oxides emission.

EXHAUST MANIFOLD: Connecting pipes between exhaust ports and exhaust pipe.

EXHAUST PIPE: Pipe connecting exhaust manifold to muffler.

EXHAUST SENSOR: A device placed in exhaust stream to measure oxygen content. It can, through an electronic control unit, be used to alter air-fuel ratios, engine timing, etc.

EXHAUST STROKE: Portion of piston’s movement devoted to expelling burned gases from cylinder.

EXHAUST SYSTEM: Parts which carry engine exhaust to rear of car—exhaust manifold, pipes, muffler, and catalytic converter.

EXHAUST VALVE (Engine): Valve through which burned fuel charge passes on its way from cylinder to exhaust manifold.

EXPANSION TANK (Cooling System): A tank, connected to cooling system, into which water can enter or leave as needed during coolant heating (expansion) or cooling (contraction).

EXPANSION VALVE (Air Conditioning): Device used to reduce pressure and meter flow of refrigerant into evaporator.