SHORT CIRCUIT--An unintentional current path
RPM (REVOLUTIONS PER MINUTE)--A mea-
between two components or a component and
sure of rotational speed.
ground; usually caused by a malfunction.
SAE HORSEPOWER--A measurement based upon
SHUNT--A resistive device placed in parallel with
the number of cylinders and the cylinder diameter.
another component to protect the component from
SAE--Society of Automotive Engineers.
excessive current.
SCAVENGING--In an internal-combustion engine, it
SIGHT GLASS--A glass window in an
is the cleaning or blowing out of exhaust gases in
air-conditioning system used for detection of
the cylinders upon completion of the power stroke.
moisture or bubbles. Also used in other systems as
SEALED BEAM--A special type of headlight in
a liquid level indicator.
which the reflector and lens are sealed together to
SLIP JOINT--In a drive train, a variable-length
enclose and protect the filaments.
connection that permits the propeller shaft to
SEALED BEARING--A bearing that has been lubri-
change effective length. Used in a variety of other
cated and sealed during manufacturing and cannot
applications.
be lubricated during service.
SOHC--Single overhead camshaft.
SEAT--The surface upon which another part rests.
SOLENOID--An electromagnetic device that
SECONDARY BRAKE SHOE--A brake shoe that is
changes electrical energy into mechanical motion;
installed facing the rear of a vehicle.
based upon the attraction of a movable iron plunger
to the core of an electromagnet.
SECONDARY WIRES--The wire from the coil to
the distributor central tower and the spark plug
SOLID--The form of matter that has a definite shape
wires in an automotive ignition system.
and a definite volume.
SELF-ENERGIZING--A brake shoe that develops a
SOUTH POLE--The pole of the magnet into which it
wedging action to assist in the braking action.
is assumed the magnetic lines of force pass.
SELF-INDUCTION--The
production
of
a
SPARK PLUG--The assembly that includes a pair of
counterelectromotive force in a conductor when its
electrodes which has the purpose of providing a
own magnetic filed collapses or expands with a
spark gap in the engine cylinder.
change in current in the conductor.
SPECIFIC GRAVITY--The ratio of the weight of a
SEMI-ELLIPTICAL SPRING--A series of leaf
substance to the weight of an equal volume of
springs starting with the longest on top and a
chemically pure water at a given temperature.
number of progressively shorter springs attached
SPEEDOMETER--An indicating device, usually
below.
connected to the transmission, that indicates the
SEPARATOR--A device whose primary function is
speed of motion of the vehicle.
to isolate undesirable fluids and or contaminants by
SPEED--Rate of motion.
physical properties other than size.
SPIDER--In planetary gear sets, the frame, or part, on
SERVO--A device used to convert a small movement
which the planetary gears are mounted.
into a greater movement of force.
SPIRAL BEVEL GEAR--A bevel gear having
SHIM--A strip of copper or similar material, used
curved teeth.
under a bearing cap or behind a gear for example, to
SPLINE--A slot or groove cut in a shaft or bore; a
adjust clearance. Also used as a means to adjust or
splined shaft onto which a hub, wheel, etc, with
alter pressure control valves and thermostats
matching splines in its bore is assembled so the two
opening pressure.
must engage and turn together.
SHOCK ABSORBER--A device in an automotive
SPRAG CLUTCH--A form of overrunning clutch;
suspension system placed at a vehicle wheel to
power can be transmitted through it in one direction
regulate spring rebound and compression.
but not in the other.
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