DEFINITION OF TERMS-CONTINUED
Cycle. A series of events with a start and finish during
Detonation. In the engine, excessively rapid burning of
which a definite train of events takes place. In the
the compressed fuel-air mixture so that knocking results.
engine, the four piston strokes (or two piston strokes on
two-stroke cycle engine) that complete the working
Diaphragm. A flexible membrane, usually made of fabric
process and produce power.
and rubber in automotive components, clamped at the
edges and usually spring-loaded; used in fuel pump,
Cylinder. A tubular-shaped structure. In the engine, the
vacuum pump, distributor, etc.
tubular opening In which the piston moves up and down.
Diesel Engine. An engine using the diesel cycle of
Cylinder Block. That part of an engine to which, and In
operation; air alone is compressed and diesel fuel is
which, other engine parts and accessories are attached
Injected at the end of the compression stroke. Heat of
compression produces Ignition.
Cylinder Head. The part of the engine that encloses the
Dieseling. A condition In which an engine continues to
cylinder bores; contains water jackets (on liquid-cooled
run after the Ignition is turned off. Also referred to as
engines) and valves (on I-head engines).
Cylinder Sleeve. A pipe-shaped removable Insert used
Differential. A mechanism between axles that permits
as the cylinder wall on some engines.
one axle to turn at a different speed than the other and,
at the same time, transmits power from the driving shaft
Damper. A device for reducing the motion or oscillations
to the axles.
of moving parts, air, or liquid.
Differential Winding. In electrical machinery, a winding
Dash Panel. The partition that separates the driver's
that is wound In a reverse direction or different direction
compartment from the engine compartment. Sometimes
than the main operating windings. The differential
winding acts to modify or change the action of the
machine under certain conditions.
Dashpot. A unit used to slow down movement or arrest
vibrations or oscillations of a moving part.
Diode. A device that permits current flow In one
direction and resists flow in the other.
DC. Direct current, or current that flows in one direction
Disk Brake. A braking network that uses a rotating disk
called a rotor and stationary brake pads such that when
Dead Axle. An axle that simply supports and does not
forced together perform a retarding action.
turn or deliver power to the wheel or rotating member.
Disk Wheel. A wheel constructed of stamped steel.
Deceleration. The process of slowing down; opposite of
Displacement. The total amount of air or liquid an object
consumes while moving from one location to another.
Degasser. A device used In connection with carburetors
for shutting off the flow of fuel during deceleration so that
Distribution Tubes. Tubes In the cooling system used to
gases from Incomplete combustion during deceleration
direct coolant flow to vital areas.
Distributor. See Ignition Distributor.
A substance used to absorb and retain
DOHC. Double overhead camshaft.