review mod 1-6 Flashcards
how many crankshaft revolutions in a full 4 stroke cycle ?
Two
metallic sodium cooled valves
sodium melts and the liquids take heat away from the valve head
piston displacement formula
V=A x h
compression ratio
=Total Volume/comb camber
oil viscosity
resistance to flow
oil flash point
temp at which a liquid begins to give off ignitable vapors
oil fire point
temp at which a liquid there are sufficient vapors to support a flame
oil cloud point
temp at which it wax content begin to solidify and separates on crystals
oil pour point
lowest temp at which it flows or can be poured
functions of lubricating oil
- reduce friction
- seal
- cushion
- cooling
- cleaning
- corrosion
- hydraulic action
type of oil sump
gear type constant displacement
what is a gerotor pump
another type of constant displacement,consist in an engine -driven spur gear that rotates within a free sniping rotor housing
scavenge pump
return oil to the reservoir, can be gerotor or gear pump
what means updraft or downdraft in carbs,
- direction of the air flow
- most AC used updraft
what is a throttle valve or butterfly valve
controls the amount of air passing through carburetor
main metering on (carbs )
supplies fuel to the venturi at all speeds above idle
main discharge nozzle (carbs)
incorporate an air bleed which helps atomize fuel (breaks fuel tension )
air bleed (carbs)
used to emulsify the fuel and breaks the surface tension in main metering jet (also used in the idle to emulsify fuel)
Idling
throttle valve is nearly closed (pressure differential not enough to draw out fuel from the main discharge nozzle )
idle valve
-connected to the throttle
-controls fuel flow for 1-3 degrees
-to maintain metered fuel pressure at idle power
settings
-above 3 degrees throttle movement has not metering
effect
continuous-flow injection system
fuel is injected and mix with air in each intake port
types of fuel injection systems
- precision airmotive RSA
- teledyne-continental
advantage of fuel injections
-correct amount of fuel per each cylinder
-less susceptible to ice build up
-Increase power over Carbs
-does not required priming system
-fuel pressure is maintained above vapour formimg
pressure
fuel injection basic components
- fuel pump (creates positive pressure)
- fuel metering (meters fuel)
- fuel distribution ( ensure fuel delivery)
- fuel injection (consistent spray pattern)
what types of pump has fuel injections systems
- gear
- vane
function of fuel metering (injections)
the fuel control unit manages the throttle and mixture inputs (venturi housing)
fuel distribution
- delivering the regulate fuel to the nozzles
- flow divider
- manifold valve assembly
- distribution valve
fuel injectors
threaded into the cylinder head near the intake port
Bendix fuel injection
Venturi housing, fuel metering unit and fuel regulator are cast as a single unit
what kind of pump used Bendix system
airframe fuel pump (engine driven fuel pump) EDFP and uses fuel and air to metering forces to meter fuel
function of the ball valve in Bendix regulator
create differential pressure across the metering jet
Constant head idle spring
holds valve off the seat when air flow is low (idle)
Constant effort springs
pre-loads the air diaphragm
provides smooth transition between idle and cruise power
mixture control and throttle valve linkage
from pilot
main metering jet
meters fuel
enrichment jet
provides more fuel at high power settings
purpose of fuel metering
supply the correct amount of fuel to engine
fuel metering consist of?
- 4 chambers
- air/fuel diaphragm
- ball valve
function of variable orifice in a fuel pump
- used above cruise power
- sets fuel pressure proportional to the engine speed
function of the relief valve in a fuel pump
- excess fuel return to the inlet of the pump
- helps maintain constant output pressure
function evacuated bellows in a fuel pump
-aneroid bellows
-allows turbo charger to catch up, preventing rich
mixture
-turbo charger (upper deck pressure is sensed on the bellows)
fuel control unit
receive inputs from pilots throttle and mixture control
fuel metering valve
control by throttle position
fuel injections adjustments
idle mixture and idle speed
