DICTIONARY OF AUTOMOTIVE TERMS - "Ex"
- Examination:
- See:
metallographic examination
- Exc:
- Abbreviation for "excellent," as in exc condition.
- Excalibur:
- A vehicle brand of which the 1965-69 model II Series I are
milestone cars.
- Exchange engine:
- A replacement engine which is provided in exchange for a worn engine while the
original engine is being rebuilt
- Exchange process:
- See:
charge exchange process
- Exchanger:
- See:
heat exchanger.
- Excelsior:
- The 1925-1948 models with required application are
classic cars.
-
Excitation current:
- The electric current in the shunt field of an electric motor resulting from
voltage applied across the field
- Excitation winding:
- Field winding
- Excite:
- To pass an electric current through a unit such as
the field coils in the
generator.
- Exciter coil:
- A primary coil which provides stepped up
voltage to a second
coil.
- Exciter winding:
- Field winding
- Excluder:
- See:
draught excluder
- Ex-demonstrator:
- A vehicle which had been used as a demonstrator
and is now available for sale
- Exducer:
- The outermost section of a turbine wheel, used
to purge the turbine of exhaust gases
- Executive car:
- A large, powerful luxury car considered suitable for a business executive
-
Exempt Carrier:
- A company which transports commodities exempted from Interstate
Commerce Commission (ICC) economic regulation.
- Exfiltration:
- Slow flow of air from the building to the outdoors.
- Exhaust:
- To expel spent fumes.
- The spent fuel after combustion takes
place in an internal combustion
engine. Sometimes it refers to the exhaust
system.
Also See:
dual exhaust system
intake over exhaust engine
raw exhaust gas
residual exhaust gases
tuned exhaust
tuning the exhaust
-
Exhaust back pressure:
- Any pressure holding back the flow of the gases in an exhaust system. Pressure
exerted in exhaust system in reverse direction. Also called
back pressure
-
Exhaust back pressure transducer valve:
- (BPV or BPS) a device used to sense exhaust pressure changes and control
vacuum to the EGR valve in response to these changes
-
Exhaust Brake:
- An engine device which changes exhaust pressure to assist in
slowing down a vehicle. Also called an exhaust retarder
- Exhaust cam:
- A separate camshaft controlling the opening and closing of the exhaust valves
used in twin overhead camshaft engines
- Exhaust camshaft:
- A separate camshaft controlling the opening and closing of the exhaust
valves used in twin overhead camshaft engines
- Exhaust chamber:
- Part of the two-stroke exhaust system designed to maintain a specified back
pressure
- Exhaust cutout:
- A Y-shaped device that is placed in the exhaust pipe
ahead of the muffler. The
driver may channel the
exhaust through the muffler or out the other leg of the "Y"
where the exhaust passes out without going through the muffler.
Also See:
cutout
- Exhaust donuts:
- The small rubber hangers used to suspend the exhaust system from the chassis pan
- Exhaust emission:
- See:
exhaust emissions.
-
Exhaust emission control:
- See:
exhaust emission controls
-
Exhaust emission controls:
Systems or adjustments designed to limit noxious gases in an engine's
exhaust. Such controls can be grouped into two broad
categories: those designed to reduce or eliminate the formation of harmful
pollutants in the engine itself (e.g., retarded
spark setting) and those designed to destroy or
otherwise alter the pollutants after they have been formed (e.g.,
air injection,
thermal reactors, and
catalytic converters). Evaporative emission
controls prevent gasoline vapors from escaping into
the atmosphere from the fuel tank and
carburetor and
crankcase controls recycle fumes from the
crankcase through the engine.
- Exhaust emission control system:
- A
general term for any system that reduces the harmful exhaust emissions of a motor vehicle,
including one or all of the following systems: catalytic converter (with or without oxygen sensor
air/fuel control), exhaust gas recirculation, secondary air injection or induction, and positive
crankcase ventilation
- Exhaust
emissions:
- The unburned hydrocarbons,
carbon monoxide,
oxides of nitrogen, and other noxious gases emitted when
gasoline is burned in an engine.
- Exhaust engine:
- See:
intake over exhaust engine
- Exhaust gas:
- Gas which is the
product of the combustion process and which is passed out of the cylinder through the exhaust
valve or port into the exhaust system.
Also See:
exhaust gases
raw exhaust gas
residual exhaust gases
- Exhaust gas
analyzer:
- An instrument for determining efficiency with which an engine is burning
fuel.
Also See:
exhaust-gas analyzer.
- Exhaust-gas
analyzer:
- An instrument used to measure the
exhaust gases (in parts per million, percent, grams per
kilometer, or grams per mile) to determine both
combustion
efficiency and the amount of pollutants in the
exhaust.
- Exhaust gas
check valve:
- (EGC) a device that allows air injection system air to enter the exhaust
manifold, but prevents a reverse flow in the event of improper operation of other
components
- Exhaust gas
oxygen sensor:
- (EGO) a device that changes its output voltage as the exhaust gas
oxygen content changes when compared to the oxygen content of the atmosphere. This constantly
changing voltage signal is sent to the processor for analysis and adjustment to the air/fuel
ratio
- Exhaust gas purification system:
- An
emission control system for diesel engines, which may consist of an exhaust scrubber, a diesel
exhaust filter, and/or a catalytic converter
- Exhaust gas
recirculation:
- See:
exhaust-gas
recirculation.
- Exhaust-gas
recirculation:
- (EGR) An emission
control system where some of the exhaust gases
are rerouted from the exhaust manifold into the
combustion chamber to make sure that all
fuel is burned before entering the atmosphere. The process lowers the
combustion temperature and reduces the formation of
oxides of nitrogen (NOx) in the exhaust.
- Exhaust gas recirculation
system:
- (EGR) a system used to control oxides of nitrogen (NOx) the exhaust gases are
recirculated, lowering the engine combustion temperature, thereby reducing engine
pollutants
- Exhaust gas recirculation valve:
-
A valve which admits exhaust to the incoming air/fuel mixture
- Exhaust gases:
- The burned
and unburned gases which are expelled out of the
exhaust system after
combustion takes place.
Also See:
exhaust emissions
- Exhaust header:
- Steel
tubing connecting pipes between the exhaust ports and
the exhaust pipe. Usually a
header has been polished
to allow for better flow of the exhaust.
Also See:
exhaust manifold
- Exhaust
heat control valve:
- (HCV) a valve which routes hot exhaust gases to the intake manifold
heat riser during cold engine operation. Valve can be thermostatically controlled, vacuum
operated or computer controlled
- Exhaust manifold:
The connecting pipes between the exhaust ports of
each cylinder and the
exhaust pipe. It is usually made of cast iron.
Sometimes called the "exhaust header " but it is
usually made of steel tubing.
- Exhaust note:
- The sound
coming from the end of the exhaust pipe. It is usually described as pleasant, loud, throaty, or
sporty.
- Exhaust oxygen
sensor:
- Device that detects the amount of oxygen in the exhaust stream and sends that
information the ECM. Also called an oxygen sensor
or an O2 sensor
- Exhaust pipe:
Pipe connecting exhaust manifold
or header to the
muffler.
- Exhaust
pollutants:
- Exhaust emissions
- Exhaust port:
- The passage in the cylinder head
which connects the exhaust valve and the
exhaust manifold. The
exhaust gases pass through the port to the
exhaust manifold or header.
- On two-stroke engines the exhaust port
is cut into the cylinder wall because it does
not have valves.
- That opening which carries the fluid to the downstream pressure of a
fluid system.
Also See:
adjustable variable exhaust
port
variable exhaust port
-
Exhaust pressure regulator:
- (EPR) a device for increasing exhaust backpressure at specific
times to increase exhaust flow to the EGR valve
-
Exhaust Retarder:
- An engine device which changes exhaust pressure to assist in
slowing down a vehicle. Also called an exhaust brake
- Exhaust scrubber:
- A
diesel exhaust gas purification system which cools the exhaust and separates nitrogen oxide and
oil vapours from the gas stream
- Exhaust side:
- The side of the
engine where the exhaust valves and exhaust manifold are located
- Exhaust stroke:
The fourth stroke of a
four-stroke cycle where the
piston moves upward from
bottom dead center to
top dead center and pushes the burned
exhaust gases out of the
cylinder.
- Exhaust system:
The pipes, resonators and
mufflers that carry the
exhaust gases from the
exhaust manifold out into the atmosphere.
Also See:
dual exhaust system
stainless-steel exhaust system
twin exhaust system
- Exhaust timing:
- Exhaust
control system developed especially for two-stroke motorcycle engines in order to enhance low
and mid-range power
- Exhaust
treatment:
- Any measures taken to reduce the pollutant concentrations in the exhaust of
an internal combustion engine released into the atmosphere
- Exhaust tuning:
- Cutting
the exhaust pipe to a length that provides maximum
efficiency.
- Exhaust
turbocharging:
- See:
turbocharging
- Exhaust valve:
- The valve through which the burned fuel charge passes on its way from
the cylinder to the
exhaust manifold. It is driven by the
camshaft. When comparing an exhaust valve with an
intake valve in the same engine, the part of
the exhaust valve that seats into the head (i.e., not
the stem) will have a smaller diameter than the
intake valve.
- A movable port which provides an outlet for the cylinder gases in a
compressor or engine.
Also See:
sodium-cooled exhaust
valve
- Exhaust valve
closes:
- (EVC) A mark on a valve-timing diagram
- Exhaust valve
opens:
- (EVO) A mark on a valve-timing diagram
- Exothermal:
- Chemical reaction
in which heat is released.
- Expander:
-
- A ring placed under a piston ring to increase ring
pressure on the cylinder walls. For instance an
oil control ring may have an expander ring to assist
the oil-control ring to scrape oil off the cylinder wall
and provide further sealing.
Also See:
piston ring expander.
- A device in a drum brake system (either hydraulic or mechanical)
which forces the shoes apart into contact with the drum.
- A disc used in a wheel cylinder which helps to seal the fit
between the cup lips and cylinder walls when there is no pressure in the
system.
Also See:
bead expander
piston skirt expander
ring expander
skirt expander
tailpipe expander
wedge expander
- Expander spacer:
- See:
expander ring
- Expanding:
- See:
piston skirt expanding
- Expansion:
- An increase in size,
for example: when a metal rod is heated, it increases in length and perhaps also in diameter.
Expansion is the opposite of contraction.
Also See:
piston expansion
shell expansion
- Expansion joint:
- Device
in piping designed to allow movement of the pipe caused by the pipe's expansion and
contraction.
- Expansion plug:
- A steel
plug, slightly dished or cup-shaped. When driven into place it flattens to fit tightly in its seat. In
an engine block, expansion plugs (also called freeze plugs or core-hole plugs) are inserted into
the holes in the casting through which core was removed when casting was formed. They open
into cooling passages and thus provide pressure relief should the engine coolant freeze and
expand.
Also See:
core plugs.
- Expansion
stroke:
- See:
power stroke
- Expansion tank:
- When
the engine is heated, the coolant expands to fill any
available space (usually in the radiator). Before the
introduction of coolant expansion tanks, the excess
coolant was forced out of a vent tube and on the ground. The
expansion tank collects the coolant so that when the engine
cools off, the resultant vacuum sucks the
coolant from the tank back into the
radiator.
- Expansion tube:
- A
device that converts high pressure liquid refrigerant into low pressure liquid refrigerant (thus
lowering its boiling point) before it passes through the evaporator. The expansion valve replaces
the thermostatic expansion valve. It is also referred to as a
fixed orifice tube
- Expansion valve:
- A
part of an air-conditioning system, located between the
condenser and the
evaporator that regulates the flow of liquid
refrigerant to the vaporator. If cooling needs are low, the
valve is almost closed; as additional cooling is required, the valve opens wider so that more
liquid refrigerant flows to the
evaporator. It reduces the pressure from the high side to
the low side and is operated by pressure. Also called an automatic expansion valve (AEV) or
"thermostatic expansion valve."
- Expansivity:
- See:
coefficent of expansion
- Expected
residual value:
- This is the projected or expected value of the vehicle at the end of the
lease. Residual value is a measure of the vehicle's expected depreciation.
- Expendable refrigerant system:
- System
which discards the refrigerant after it has evaporated.
- Expenditures:
- See:
capital expenditures
- Experiment:
- See:
windsor experiment
- Experimental Development
Program:
- See:
scientific
Research and Experimental Development Program
- Experimental Safety Vehicle:
- (ESV) A
special vehicle built for research into and testing of safety features; (compare
SID)
- Exploded view:
- A
drawing of a mechanism or structure which shows the parts separately but approximately in the
position they occupy when assembled
- Explosion:
- A rapid disintegration
of an object.
Also See:
clutch explosion.
-
Explosion-proof enclosure:
- (EXP-PRF) A special enclosed electrical motor housing designed to withstand an
internal explosion of specified gases or vapors and allow the internal flame or
explosion to escape, usually used in smaller ratings below 1/3 hp if
nonventilated (EPNV)
and in fan-cooled (EPFC)
in larger ratings
- Export Restraint:
- See:
Voluntary Export Restraint
- Expressway:
- A US multilane
highway road with limited access to be used for rapid travel with few interchanges.
- Ext:
- Abbreviation for "exterior."
- Extended Cab:
A type of pickup truck (by GM) which has a second row of seating; but unlike a
crew cab (which has four full size doors) it has a "half-door" that can be opened
only after the main door is opened. The seating is usually a little more cramped
than in a crew cab. Also called Club Cab, King Cab, XtraCab, Access Cab, SuperCab,
or Cab Plus.
- Extension:
- A part which is inserted
between a ratchet and a socket to provide access to nuts or bolts which are deeply inset or hard to
reach. Also called "extension bar" or "extension piece."
Also See:
brake extension
fender extension
load floor extension
park brake extension
piston extension screw
valve extension
wheel arch extension
wing extension
- Extension bar:
- See:
extension
wobble extension bar
- Extension
housing:
- See:
transmission
extension housing
- Extension piece:
- See:
extension
- Extension screw:
- See:
piston extension screw
- Extension spring:
- A
closed-coiled helical spring that offers
resistance to a pulling force.
- Exterior mirror:
- The
mirror that is usually mounted on the door. In Japan (and other countries) it was mounted on the
front fenders. Also called "external mirror."
- External
combustion engine:
- An engine that burns its fuel outside the engine. A
steam engine is an external combustion engine.
- External
diameter:
- The outside diameter of a cylinder, tube, or washer
- External drive:
- Term used
to indicate a compressor driven directly from the shaft or by a belt using an external motor.
Compressor and motor are serviceable separately.
- External
drive compressor:
- See:
compressor,
open type
- External
equalizer:
- Tube connected to low-pressure side of a thermostatic expansion valve
diaphragm and to exit end of evaporator.
Also See:
equalizer line
- Externally-balanced crankshaft:
- A
crankshaft that requires external balancing weight, usually on the vibration damper of the
flywheel, for balance
- External
micrometer:
- A micrometer for measuring external diameters
- External mirror:
- The
mirror that is usually mounted on the door. In Japan (and other countries) it was mounted on the
front fenders. Also called "exterior mirror."
- External mix air
cap:
- A special type of air cap for spray guns. Air and fluid are mixed in the space
outside the air cap, directly in front of the nozzle: the most common type of air cap.
Also See:
internal mix air cap
- External snap ring:
-
A split ring held in place by its own tension within the grooves cut around a shaft.
Compare internal snap ring.
- External thread:
- Thread
consisting of projecting ridges on the outside of a part such as a bolt or screw (which fits into the
corresponding internal thread of a nut). Also called male thread
- External vane
pump:
- A pump with either an elliptic rotating piston or an eccentrically mounted
circular rotor
- Extinguisher:
- See:
fire extinguisher
- Extractor:
- A device for removing
some object (e.g., bearing, bushing, sleeve, bolt, stud, etc.).
Also See:
oil and water extractor
screw extractor
stud extractor
- Extras:
- Optional items either supplied by
the manufacturer at the buyer's request, or added later by the owner. Usually they are things like
seat covers, floor mats, additional lights, sunroof, glass tinting, CD changers, etc.
- Extreme-pressure lubricant:
- (EP lubricant)
A lubricant designed and compounded to withstand very
heavy loads imposed on gear teeth.
- Extruder:
- A machine that shapes a
rubber compound into a usable form. Uncured rubber is heated to soften and forced through dies
having the desired shape and dimensions.
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