Fuel Metering Vocab

Front 1

Stoichiometric mixture

Back 1

A mixture of feul and qir in which all the oxygen and fuel are consumed in an engine and max amount of heat energy is extracted from the fuel.

Front 2

Lean

Back 2

A fuel/ air mixture characterized by an excess amount of air for a given amount of fuel.

Front 3

Full rich

Back 3

That position of the mixture control that permits the max amount of fuel to flow to the engine relative to airflow.

Front 4

Rich

Back 4

A fuel/air mix characterized by an excess amount of fuel for a given amount of air.

Front 5

Rich best power

Back 5

The high end of a range of mixture settings for a reciprocating engine in which the max speed or manifold pressure is developed for a given throttle position.

Front 6

Throttle valve

Back 6

The valve in the carburetor of a fuel control unit that determines the amount of fuel/air mixture to be fed to the engine.

Front 7

Updraft

Back 7

A type of carburetor or fuel control unit in which induction air is routed through the device from bottom to top

Front 8

Idol-cuttoff

Back 8

That position of the mixture control in which fuel is prevented from flowing from the metering system into the engine.

Front 9

Best Economy

Back 9

Fuel/air mixture in reciprocating engines that achieves the greatest range of flight.

Front 10

Lean best power

Back 10

The low end of a range of mixture setting for a reciprocating engine in which the max speed or manifold pressure is developed for a given throttle position.

Front 11

Detonation

Back 11

The sudden release of energy of heat energy from fuel in an aircraft engine caused by the fuel-air mix reaching its critical pressure and temp.

Front 12

Backfire

Back 12

A burning or explosion within the induction system when the fuel-air mixture is ignited by gasses that are still burning in the cylinder when the intake valve opens.

Front 13

After firing

Back 13

A condition that often results from either too rich a fuel/air mixture or unturned fuel being pumped into the exhaust and ignited when it comes in contact with a hot component.

Front 14

Downdraft

Back 14

A type of carburetor or fuel control unit in which induction air is routed through the device from top to bottom

Front 15

Float chamber

Back 15

The area in a float carburetor in which fuel is stored

Front 16

Boost venturi

Back 16

A small venturi whose discharge end is a the throat of the main venturi and which surrounds the main discharge nozzle of a float type carburetor.

Front 17

Pre ignition

Back 17

Ignition occurring in the cylinder before the time of normal Ignition.

Front 18

Throttle valve

Back 18

The valve in the carb of a contol unit that determines the amount of fuel/ air mixture to be fed to the engine.

Front 19

Primary Venturi

Back 19

The Air restrictor in the throttle body of many fuel metering devices that meters fuel for normal operations above idle speed.

Front 20

Needle valve

Back 20

A tapered-end, fluid control needle valve that fits into a seat or recess to control or restrict the flow of fluid through an orifice.