| Electrically
controlled transmission (ECT) |
A
transmission which uses microprocessors and electronic devices to
control shift points and other functions rather than mechanical components.
|
|
|
| Electrode |
A
terminal in an electric circuit that is separated by a gap which electricity
must "jump". Commonly associated with the center and side
electrodes of a spark plug. In a spark plug, electricity enters the
top of the plug and flow down to the center electrode. The electricity
seeks the "ground" which is the curved electrode at the
bottom of the spark plug which is affixed to the plug's body (ground).
|
|
|
| Electrolyte |
Any
solution that conducts an electric current. In a car battery, hydrochloric
acid and distilled water is the electrolyte. It reacts with the battery's
lead plates to produce voltage and current. |
|
|
| Electronic
accelerator |
A
system where an electric motor is used to control the engine's throttle
(engine speed) rather than a mechanical linkage. Found in newer vehicles
such as the Corvette. Also see Drive by wire. |
|
|
| Electronically
adjustable shock absorber. |
A
shock absorber who's dampening characteristics can be made stiffer
or softer by electronic switching, typically by an electric solenoid.
Can be switched manually or by the vehicle's computer. Allows a driver
or engineers to customize ride and handling characteristics for differing
vehicle speeds or types of terrain. For example, many vehicles feature
driver-selectable ride modes such as "Plush" or "Sport".
In most applications, a solenoid mounted on or inside the shock absorber
rotates a plate inside the shock absorber which changes the orifice
size which oil in the shock must flow through as the shock's piston
moves as bumps are encountered. A smaller orifice size restricts oil
flow more and produces a stiffer ride. |
|
|
| Electronic
control module (ECM) |
A
box that contains a small computer which monitors and controls engine
and transmission as well as emission controls, antilock braking control,
air bag functions. Multiple control modules are often used for different
functions. For example, an antilock brake module is often separate
from engine and transmission control. Also called, Electronic Control
Unit, Engine Control Module, Black Box, Brain Box, and The Computer. |
|
|
| Electronic
distributor |
An
electronic spark distribution system which replaces the traditional
mechanical distributor in an automobile. Many such systems use a magnetic
pulse generator and electronic switching box. The advantage of this
system is more precise control over timing, plus reliability is improved
-- there are no moving parts so it doesn't wear out. |
|
|
| Electronic
engine management |
A
microprocessor based (computerized) system that controls an engine's
fuel delivery and ignition system. Many systems often go a step further
and incorporate antiknock sensors that can detect detonation in the
cylinders and overcome it by retarding the spark. |
|
|
| Electronic
fuel injection (EFI) |
See
Fuel Injection. |
|
|
| Electronic
idle control |
Part
of an electronic engine control management system that uses feedback
from sensors to maintain a smooth steady idle even if the air conditioning
compressor or other accessories are engaged. Also compensates for
changes in ambient temperature and altitude. |
|
|
| Electronic
ignition |
An
ignition system that uses electronic devices in place of mechanical
parts to control engine spark and timing. The three main types of
systems include: 1) Contact controlled - breaker points are maintained
but trigger a transistor that controls the spark. 2) Magnetically
controlled - ignition points are eliminated, a magnetic pickup sends
a signal to a transistor which controls spark switching. 3) Capacitor
controlled - which can be all electronic or controlled by breaker
points. |
|
|
| Electronic
temperature control |
See
Automatic climate control. |
|
|
| Electronic
trailer brake controller |
An
auxiliary brake controller that produces an electric brake signal
to a trailer based on the tow vehicle's own braking. Allows a driver
to operate vehicle and trailer brakes simultaneously. An under-the-dash
controller is connected to the vehicle's hydraulic brake line (usually
with a "T" connector) near the master cylinder. When the
driver applies the brakes, the controller senses the hydraulic pressure
and converts it into an electric current which is fed by wires to
the trailer and used to control it's brakes. Most electronic trailer
brake controllers have a sensitivity control dial which allows the
driver to fine-tune the amount of pedal pressure required to apply
the trailer brakes. The harder the brakes are applied, the harder
the trailer's brakes are applied. Without brakes on a trailer, a vehicle
towing a loaded trailer requires a much longer braking distance which
can be unsafe. Also see Towbar and Brake system. |
|
|
| Electronic
transmission control |
A
transmission which uses microprocessors and electronic devices to
control shift points and the appropriate gear for the driving conditions.
Sensors provide the transmission with information about vehicle speed,
engine load, throttle position, and other factors. Many pickup trucks
and performance cars also allow the driver to choose various shift
settings which can delay shift settings for higher rpm revving. In
pickup trucks, a special setting allows the driver to choose a towing
setting which lets the engine rev higher reducing strain on the transmission. |
|
|
| Emergency
brake |
A
brake system separate of the hydraulic braking system to slow the
vehicle if the normal brakes should fail, or to hold the vehicle in
place (parking brake). Emergency brakes are typically mechanical using
a series of cables and levers that lead to a hand lever or foot pedal. |
|
|
| Emergency
tensioning seat belt retractors |
A
spring-loaded part of the seat belt system that allows the seat belt
to move in or out freely for driver comfort and retracts the seat
belt when not in use. It also locks the seat belt in place in the
event of a collision or emergency maneuver -- typically by the use
of an inertia- sensing mechanism (moving weights). |
|
|
| Emission
controls |
Systems
used on modern vehicles to reduce or limit noxious gasses emitted
from the exhaust system. There are two basic approaches, one is to
reduce or eliminate the formation of harmful pollutants before they
form through the use of efficient combustion chamber design and precise
fuel metering. Another approach reduces, alters, or destroys noxious
pollutants after they are formed by using a system of air injection
and crankcase fume controls (PVC valve) at the engine, and a catalytic
converter in the exhaust system. The emission control system on most
vehicles is controlled by the vehicle's computer. |
|
|
| End
gap |
The
distance between the ends of a piston ring when placed in an engine's
cylinder. Most engines use at least three piston rings - two compression
and one oil ring. The rings must be installed on the piston so the
gap of each ring is staggered from the gap of other rings to prevent
exhaust gasses from leaking by.
A
ring's end gap and a feeler gauge can be used to quickly determine
cylinder wear. The end gap should remain similar throughout the
entire portion of a cylinder. A larger gap at the top of a cylinder
indicates cylinder wear. Too large of a gap throughout the cylinder
may indicate the need for oversized piston rings or complete remachining
of the cylinders.
|
|
|
| End
gas |
The
part of the air/fuel mixture that burns in the cylinder last. Also
see Detonation and Ping. |
|
|
| End
links |
See
Sway bar end links. |
|
|
| End
plate |
Part
of the wing structure on a Formula or Indy-type race car. The vertical
side of the car's body structure that the wing attaches to. Also called
Tip Plate because the wing can be 'tipped' or rotated to adjust turbulence
characteristics. |
|
|
| Energy
absorbing bumper |
A
front or rear bumper design that allows a vehicle's front or rear
end absorb low-speed impacts without incurring any substantial damage.
Some designs incorporate a shock absorber-like device, other vehicles
use a movable bumper and foam or a flexible plastic honeycomb device.
U.S. government standards require automobiles to be able to sustain
impacts up to 2.5 mph without damage. Many auto manufacturers design
their vehicles to withstand up to 5 mph impacts. |
|
|
| Energy
absorbing steering column |
A
steering column design that allows the steering column to collapse
during a severe frontal impact to minimize harm to the driver. |
|
|
| Energy
absorbing steering wheel |
A
steering wheel designed to flex, bend or give way under impact of
a drivers body to reduce harm in a severe front end collision. |
|
|
| Engine |
The
part of an automobile that produces power which drives the vehicle.
Inside an engine are pistons which fit tightly into cylinders. Through
the use of timing, valves, and a spark plug, an air/fuel mixture is
ignited inside the cylinders (called the combustion chamber) which
produces a powerful explosion. The force of the explosion (it's expanding
gases) moves pistons downward inside the cylinder. The reciprocating
motion of the pistons is converted to rotating motion by the crankshaft
which turns the transmission and ultimately the wheels. Also see Four-stroke
cycle. |
|
|
| Engine
block |
The
lower part of an engine (usually constructed of cast iron or cast
aluminum) which includes the cylinders and crankcase. You might consider
this the foundation of an engine since many of the most critical components
like the crankshaft, camshaft, pistons and cylinder heads mount to
the cylinder block. Also called, Cylinder Block, or just Block. |
|
|
| Engine
control module |
See
Electronic Control Module (above). |
|
|
| Engine
detailing |
The
process of making an engine compartment look new or appear more
presentable either for show or sale. Auto detailers and used car
dealers detail newer vehicle engine compartments usually beginning
with a thorough degreasing, followed by touching up engine color
(where needed), painting brackets, replacing unsightly components
with new then applying an engine dressing compound which makes parts
appear more shiny.
Engine
compartments on classic cars usually require a more thorough job.
Restorers may remove the engine for complete rebuilding and painting,
and the engine compartment and brackets are sandblasted and repainted
to factory colors. Then the engine is reinstalled with new components
and warning stickers of OEM type and markings (belts, hoses, wires,
etc.). Also see OEM
|
|
|
| Engine
dressing |
Applying
chrome parts and choosing components such as bolts, spark plug wires,
distributor cap, hoses and wire looms whose styles and colors complement
each other, engine color and the color of vehicle. Used by street
rodders and racers to produce an engine compartment pleasing to look
at. |
|
|
| Engine
mounts |
Special
rubber and metal parts which secure the engine and transmission to
the vehicle's frame. Rubber is used in it's construction to reduce
engine and transmission vibration from being transmitted to the passenger
compartment. Engine mounts also are designed to flex due to engine
torque. Also called Motor Mounts. |
|
|
| Engine
speed |
The
speed an engine's crankshaft turns. Measured in revolutions per minute
(RPM). |
|
|
| English
wheel |
A
heavy-duty, floor-standing piece of equipment used by auto designers
and racers to shape flat sheet metal or aluminum into curved, custom
body panels. The device has long C-shaped arms that contain interchangeable
rollers of varying contours. When a piece of sheet metal is rolled
back-and-fourth between the tight-fitting rollers it begins to bend.
In the hands of a skilled craftsman, nearly any shape of body panel
can be produced. Used by auto designers to make body panels for prototype
vehicles and racers to produce custom aerodynamic body panels for
race cars. |
|
|
| Environmental
protection agency |
A
U.S. government agency created in 1970 to design and carry out pollution
control programs. The EPA sets fuel emission standards and designs
tests to ensure emission compliance. One EPA standard widely known
is for determining a vehicle's fuel economy. Manufacturers must use
the EPA standards to calculate and label every vehicle's fuel economy. |
|
|
| EP
lubricant |
Extreme
Pressure lubricant. A lubricant that can withstand high pressures,
such as between gear teeth. An example is gear lube, used in manual
transmissions. |
|
|
| Equalizer |
An
electronic device used on some car stereo systems to allow the fine-tuning
of different frequencies to the desired taste of the listener. Can
be a simple tone control, or a graphic equalizer that can adjust
many frequencies.
The
term equalizer is also used to describe the short section of pipe
that bridges two exhaust pipes. Part of the "H pipe".
The equalizer tube balances (equalizes) high pressure resonance
and exhaust pulses between pipes. Also referred to as a balance
tube/pipe.
|
|
|
| Equal-length
driveshafts |
A
drivetrain design that uses axles of the same length. With front wheel
drive cars, the location of the transmission behind a motor which
sits sideways in the engine compartment usually further to the driver's
side. This leads manufacturers to use unequal-length driveshafts.
Unequal-length driveshafts can lead to torque steer -- a tugging or
pulling condition on the steering wheel that occurs during acceleration.
Using axles of the same length can help eliminate torque steer. |
|
|
| Ergonomics |
The
study of how people use and comprehend machines, and how machine design
can effect comfort, efficiency and safety. Automotive engineers carefully
consider the design and placement of seating, knobs, switches, steering
wheel, and shifter to increase driver comfort and safety. |
|
|
| Estate
car |
A
term once used to describe a station wagon. |
|
|
| Ethanol |
A
shortened term for Ethyl alcohol which is a fuel substitute derived
from distilling renewable plant sources -- usually corn or sugarcane.
It can be used by itself or mixed with gasoline (gasohol). Was considered
a way to extend scarce fuel supplies during the energy crisis of the
70's and early 80's in the U.S.. Ethanol contains less heat energy
than gasoline (75,560 Btu/gal vs. 115,400 Btu/gal). Ethanol can be
used in an automobile engine alone if the engine is properly set up.
It is used widely used in other parts of the world such as Brazil
(derived from sugarcane and beat sugar) and the Philippines (distilled
coconut husks) to reduce dependence on foreign oil and effectively
reduces noxious pollution in densely populated cities. Also called
grain alcohol. |
|
|
| Ethyl |
A
brand of gasoline to which compounds were added to increase it's octane.
It became a generic term for high-octane fuel but is seldom used anymore. |
|
|
| Ethylene
glycol |
The
primary ingredient used in antifreeze. See Antifreeze. |
|
|
| Evaporative
canister |
See
Evaporative emission controls (below). |
|
|
| Evaporative
emission controls |
A
pollution control system used on automobiles that captures fuel vapors
from the fuel tank and prevents them from being emitted into the atmosphere.
The primary part is the evaporative canister, basically a coffee can-sized
container filled with activated charcoal. The canister is connected
to the fuel tank and carburetor (or fuel injection system) via hoses
and steel lines. Any gasoline vapors or vapor-filled air that builds
up in the tank (through expansion) passes through the hoses into the
charcoal canister where the vapors are absorbed and 'captured' by
the charcoal. When the engine is started, vacuum from the engine's
intake manifold draws fresh air through the canister pulling the gasoline
vapors out of the charcoal and into the motor where they can be combusted.
Also referred to Vapor Recovery System. |
|
|
| Evaporator |
A
component of a vehicle's air-conditioning system resembling a miniature
radiator where the refrigerant changes from a liquid to a vapor. The
change of states extracts heat from the surrounding air which produces
the desired cooling effect. The evaporator looks like a miniature
radiator and is typically located inside the heating and air-conditioning
box on or near the firewall. |
|
|
| Exhaust
emission controls |
A
system used to reduce or limit noxious gasses emitted from a vehicle's
exhaust system. There are two basic approaches, one is to reduce or
eliminate the formation of harmful pollutants before they form through
the use of efficient combustion chamber design and fuel injection.
Another approach reduces, alters, or destroys noxious pollutants after
they are formed by means of using a system using air injection and
crankcase fume controls (PVC valve) at the engine, and a catalytic
converter in the exhaust system. The emission control system is in
part controlled by the vehicle's computer. In many states and cities,
vehicles must be inspected regularly to ensure the exhaust emission
control system operates properly. |
|
|
| Exhaust
emissions |
A
term typically applied to noxious gasses and other pollutants such
as unburned hydrocarbons, carbon monoxide, NOx (nirtrous-oxides) emitted
from a vehicle's exhaust. |
|
|
| Exhaust
gas analyzer |
A
device used by mechanics and emission control stations to measure
the quantity (in parts per million) and type of pollutants emitted
by a vehicle's exhaust. An important tool for analyzing engine problems
and performing tune-ups because it can help determine how efficiently
an engine burns fuel. Also called a Combustion Gas Analyzer. |
|
|
| Exhaust
gas recirculating |
An
emission control system where a small amount of an engine's exhaust
gasses are picked up from the exhaust manifold and recirculated back
into the carburetor or fuel injection system to be re-burned. Lean
air/fuel mixtures reduce CO and HC(hydrocarbon) emissions but also
lead to higher cylinder temperatures which raise NOx emissions. By
mixing some exhaust gasses with a fresh air/fuel mix, leaner air/fuel
ratios can be used and lower combustion temperatures can be maintained
while at the same time reducing NOx emissions. |
|
|
| EGR
valve |
A
vacuum operated valve used on engines to regulate the amount of exhaust
gasses recirculated in an exhaust gas recirculating system. See Exhaust
Gas Recirculating (above). |
|
|
| Exhaust
collector |
A
cone-shaped device that acts as an interface between the exhaust pipe
and header pipe, and channels the exhaust from the larger header output
pipe into the usually smaller exhaust pipe. Normally, one end is welded
to the exhaust pipe, the other end contains a mounting flange that
allows it to be bolted to the header pipe (with gaskets in between).
May have internal vanes to reduce swirling. |
|
|
| Exhaust
donut gasket |
A
round, doughnut-shaped gasket made of special temperature resistant
material that seals the joint between an exhaust manifold and exhaust
pipe. Commonly used on cars and trucks produced in the 1960s and 70's.
The gasket produces a seal at a joint which must withstand some movement
(the engine rocks slightly during acceleration). The gaskets were
somewhat problematic and would wear out and produce nagging exhaust
leaks at the manifold. Another method of sealing the exhaust involves
using a flanged pipe and rounded mating surface at the exhaust manifold
output. |
|
|
| Exhaust
flange |
A
flange that allows an exhaust pipe to be mounted to another exhaust
component such as a exhaust manifold or catalytic converter. Flanges
can be flat steel that bolt to other flat flanges, or they may take
the form of a flared end and a special bracket that holds the flared
end tight against a coned-shaped surface of another component such
as the output side of an exhaust manifold. |
|
|
| Exhaust
hangers |
A
metal and rubber assembly that supports an exhaust system to the vehicle
chassis. Used on all vehicles. May be a metal strap with a rubber
strip, or metal hooks that use heavy rubber O-rings to support the
muffler, catalytic converter and tailpipe. The rubber reduces exhaust
noise and vibration transmission to the vehicle. A broken or rusted
muffler hanger can allow part of an exhaust system to hang down stressing
other exhaust components leading to premature exhaust system failure. |
|
|
| Exhaust
header |
A
component used on high performance engines similar to a cast iron
exhaust manifold that collects an engine's exhaust gasses and channels
the into one exhaust pipe. Exhaust headers are generally more efficient
and "breathe" better than a typical exhaust manifolds. A
typical exhaust manifold collects and mixes exhaust gasses emitted
from all exhaust ports. Exhaust headers manufacturers use separate
tubes for each exhaust port on the engine and attempt to create a
smoother flow of gasses out of an engine by "tuning" the
lengths of each pipe to the engine's exhaust pulses. The result is
a significant performance gain. Installing an exhaust header can increase
an engine's power substantially. On the down side, exhaust headers
are typically louder, less durable, higher maintenance and radiate
more heat than cast iron manifolds. |
|
|
| Exhaust
manifold |
A
device usually made of cast iron consisting of tubes or pathways that
collect an engine's exhaust from all exhaust ports (one per cylinder
head) and channel them into one tube. The exhaust manifold mounts
to the engine and the exhaust pipe. |
|
|
| Exhaust
manifold gasket(s) |
High-temperature
gaskets which are sandwiched between the exhaust manifold and cylinder
head to prevent exhaust gasses from leaking. |
|
|
| Exhaust
manifold paint |
Special
high-temperature paint which can be applied to exhaust manifolds that
is designed to withstand high exhaust temperatures for many years
for purposes of reducing corrosion and keep 'restored' exhaust manifolds
looking new. Used by auto restorers on classic cars where engine compartment
detail is particularly important. Generally the exhaust manifold must
be specially prepared which usually includes sandblasting, degreasing,
then the paint must be cured according to special process which may
involve slow baking in an oven (that's not a joke). |
|
|
| Exhaust
pipe |
Steel
pipe used to route an engine's exhaust gasses to the muffler and out
to the atmosphere. Pure steel is seldom used anymore because it corrodes
quickly. Alloys such as aluminized steel and stainless steel pipes
have become much more popular. A quality stainless steel exhaust system
may last the life of a vehicle. |
|
|
| Exhaust
ports |
Passages
in the cylinder head that allow exhaust gasses to be expelled past
the exhaust valves to the exhaust manifold and into the exhaust system. |
|
|
| Exhaust
stacks |
Exhaust
pipes which are positioned vertically usually behind a truck cab,
and expel exhaust gasses above the vehicle rather than below it. Used
on large semi tractors but also a custom exhaust technique used by
some pickup truck owners. Standard equipment on a line of famous 70's
Dodge Rams called the Little Red Truck. |
|
|
| Exhaust
stroke |
The
fourth stroke in a four-stroke engine where the combusted gasses are
expelled out of the cylinder. During the exhaust stroke, the exhaust
valve is opened and the piston travels upward pushing the gasses out
of the cylinder. |
|
|
| Exhaust
system |
A
system usually consisting of specially bent steel pipes, exhaust manifold(s),
muffler, resonator, catalytic converter and hangers which carries
an engine's exhaust out to the atmosphere. Another job of the exhaust
system is to reduce engine noise. |
|
|
| Exhaust
valve |
A
valve in the cylinder head which opens to allow burned exhaust gasses
out of the cylinder. When the exhaust valve is closed it seals tightly
and becomes part of the combustion chamber. Opening and closing is
controlled by the camshaft. |
|
|
| Exhaust
wrap |
Special
heat resistant strips which can be wrapped around exhaust header pipes,
primarily to reduce heat radiation in the engine compartment and prevent
damage to surrounding components, most notably spark plug wires. Header
pipes radiate significantly more heat than cast iron manifolds. |
|
|
| Expansion
plug |
A
dish-shaped plug made of steel or brass that can be driven into a
bore and seals tightly. Commonly used on the sides of engine blocks
to plug casting holes that are also used as water passages and also
on carburetors and fuel injection devices. Also called Core plugs,
Frost plugs or Freeze plugs. The name Freeze Plugs is somewhat a misnomer.
It originates from the tendency of the expansion plugs to deform if
water or coolant in the cylinder block freezes -- the plugs expand
or pop out of place. However, this is a common misconception, the
intention of the "Frost" plugs is to seal casting holes
not prevent engine damage from freezing coolant. |
|
|
| Expansion
ring |
A
piston ring used to separate two oil rings. The typical oil ring setup
consists of two thin oil rings with an expansion ring between to separate.
The expansion ring ring pushes the oil rings against the piston groove
and outward against the cylinder wall which helps it scrape oil off
the cylinder wall. Also called the Expander ring. |
|
|
| Expansion
tank |
A
reservoir in a cooling system that helps keep the cooling system filled
at all times and also collects coolant overflows. The expansion tank
on most vehicles is mounted on the fender near the radiator and connected
to the radiator via a hose near the radiator cap. If the engine becomes
too hot, expanding coolant overcomes the radiator cap pressure and
flows through the tube into the expansion tank. When, the vehicle
cools down, a vacuum will be created inside the cooling system and
coolant will be drawn back into the radiator from the expansion tank
keeping the radiator full at all times. |
|
|
| Expansion
valve |
A
valve located between the condenser and evaporator in an air-conditioning
system that regulates the flow of refrigerant to the evaporator. The
valve opens as necessary as cooling needs increase which allows more
refrigerant to flow into the evaporator. |
|
|
| External
combustion engine |
A
engine where the fuel is burned outside the engine itself. A steam
engine is an external combustion engine. |
|
|
| Extreme
pressure lubricant |
A
lubricant that can withstand high pressures, such as between gear
teeth. An example is gear lube, used in manual transmissions. Also
called EP lubricant. |
