Exhaust System; Engine Fuel System - Cessna Grand Caravan 208B G1000 Manual

SECTION 7 CESSNA
AIRPLANE AND SYSTEMS DESCRIPTION MODEL 208B G1000

EXHAUST SYSTEM

The exhaust system consists of a primary exhaust pipe attached to the
right side of the engine just aft of the propeller reduction gearbox. A
secondary exhaust duct, fitted over the end of the primary exhaust pipe
carries the exhaust gases away from the cowling and into the
slipstream. The juncture of the primary exhaust pipe and secondary
exhaust duct is located directly behind the oil cooler. Since the
secondary exhaust duct is of larger diameter than the primary exhaust
pipe, a venturi effect is produced by the flow of exhaust. This venturi
effect creates a suction behind the oil cooler which augments the flow
of cooling air through the cooler. This additional airflow improves oil
cooling during ground operation of the engine.

ENGINE FUEL SYSTEM

The engine fuel system consists of an oil-to-fuel heater, an engine-
driven fuel pump, a fuel control unit, a flow divider and dump valve, a
dual fuel manifold with 14 simplex nozzles, and two fuel drain lines. The
system provides fuel flow to satisfy the speed and power demands of
the engine.
Fuel from the airplane reservoir is supplied to the oil-to-fuel heater
which utilizes heat from the engine lubricating oil system to preheat the
fuel in the fuel system. A fuel temperature-sensing oil bypass valve
regulates the fuel temperature by either allowing oil to flow through the
heater circuit or bypass it to the engine oil tank.
Fuel from the oil-to-fuel heater then enters the engine-driven fuel pump
chamber through a 74-micron inlet screen. The inlet screen is spring-
loaded and should it become blocked, the increase in differential
pressure will overcome the spring and allow unfiltered fuel to flow into
the pump chamber. The pump increases the fuel pressure and delivers
it to the fuel control unit via a 10-micron filter in the pump outlet. A
bypass valve and cored passages in the pump body enables unfiltered
high pressure fuel to flow to the fuel control unit in the event the outlet
filter becomes blocked.
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208BPHBUS-00
U.S.
7-54