Glossary “duration” Definition:
1). The time, in crankshaft degrees, that a camshaft holds a valve open. 2. A rating system applied to engine camshafts that determines how long the valve will be open relative to crankshaft movement in degrees. 3). Time that the points are closed. 4). Time that spark is present across an air gap.
d
dust
Glossary “dust” Definition:
To damage a component.
dust coat
Glossary “dust coat” Definition:
A light, dry paint coating that is similar to a mist coat.
dust respirator
Glossary “dust respirator” Definition:
Filter that fits over your nose and mouth to block small air borne particles while sanding or grinding.
dust shield
Glossary “dust shield” Definition:
1). Upper portion of a shock absorber that surrounds the lower twin-tube unit. 2). Covering that protects an assembly from the elements: dust seal, dust boot.
Dura Spark ignition
Glossary “Dura Spark ignition” Definition:
Ignition system developed by Ford.
durability
Glossary “durability” Definition:
1). The quality of being useful, generally referring to the life of a catalyst or emission-control system. 2). The ability of a paint to maintain protection and appearance when subjected to the elements for long periods of time.
dump tubes
Glossary “dump tubes” Definition:
Straight through exhaust headers.
duo-servo
Glossary “duo-servo” Definition:
Drum brake design with increased stopping power due to the servo or self-energizing effect of the brake.
duplex
Glossary “duplex” Definition:
Simultaneous, independent, two-way transmission in both directions.
dummy
Glossary “dummy” Definition:
A mannequin, such as used in crash tests.
dummy bearings
Glossary “dummy bearings” Definition:
Machined sleeves that are easily removed from the differential carrier. They are the same outside size as the bearing, and are installed to make needed measurements during assembly. After making the needed measurements, the dummy bearing are replace with service bearing.
dummy load
Glossary “dummy load” Definition:
Electrical test procedure to simulate actual operating conditions.
dummy shaft
Glossary “dummy shaft” Definition:
Shaft used as an aid in the assembly or disassembly of a parts group.
dump station
Glossary “dump station” Definition:
A facility where RV’s and others clean their holding tanks.
duct
Glossary “duct” Definition:
Tube or passage used to provide a means to transfer air or liquid from one point or place to another.
duct tape
Glossary “duct tape” Definition:
A thick tape with a plastic body. It is sometimes used to protect parts from damage when grinding, sanding, or blasting.
ductility
Glossary “ductility” Definition:
Property of a material that permits it to be worked by drawing or stretching without rupture.
dulled finish
Glossary “dulled finish” Definition:
This ocurrs where the spray pattern overlaps an already sprayed, but dry area when painting.
ducktail
Glossary “ducktail” Definition:
An upswept rear end, often with a spoiler.