Fan
Clutch
The fan clutch is a small fluid
coupling with a thermostatic device and controls a variable-speed fan.
It ensures that the fan will rotate at just the right speed to keep the
engine from overheating, and reduces drive to the fan when it is no
longer needed. The fan clutch has a fluid coupling partly filled with
silicone oil designed for just that purpose. When the temperature of the
air passing through the radiator rises, the heat alerts a bimetal coil
spring to "uncoil" or expand. When it expands, it allows just
a little more oil to enter the fluid coupling, so the fluid coupling
starts to rotate the fan. If the air coming through the radiator is
cool, the opposite happens; the coil spring contracts, the oil leaves
the fluid coupling and the fan slows. Slowing the fan when it is not
needed reduces fuel consumption, makes less noise and saves engine
power. Sometimes a flat bimetal strip spring is used instead of a coil
spring; it bows out and in when the temperature rises and drops, letting
oil in and out of the fluid coupling.
Filler
Cap (Brake Fluid Reservoir Cover)
The cap on the brake fluid
reservoir has a hole for air, or is vented, to allow the fluid to expand
and contract without creating a vacuum or causing pressure. A rubber
diaphragm goes up and down with the fluid level's pressure, and keeps
out any dust or moisture.
Flywheel
The large wheel connected to the
crankshaft provides the momentum to keep the crankshaft turning without
the application of power, through the energy generated during the power
stroke. This energy is also used to drive the crankshaft, connecting
rods and pistons during the three idle strokes of the 4-stroke cycle.
This makes for a smooth engine speed. The flywheel forms one surface of
the clutch and is the base for the ring gear.
Frame
(Chassis)
The basic structure of the vehicle
is the frame and it provides a good anchor point for the suspension
system. There are two types of frames; integral frames, or ‘unibody’,
and conventional frames. A conventional frame is basically a ‘one-piece’
frame; or two ‘one-piece’ frames fastened together. These
frames are extremely rigid to keep all the parts of the car in perfect
alignment, which are attached to it. It is constructed of heavy steel
and welded or cold riveted together. Cold riveting keeps the rivets from
shrinking after they cool off. The integral, or unibody, frame is just
the opposite. With this type of frame, the body parts are used to
structurally strengthen the entire car, and all of the sections are
welded into one piece. Sometimes the parts of the body and the
suspension system are attached and reinforced. Also, some unibody frames
have partial front and rear frames for attaching the engine and
suspension members.
Fuel Pump
The fuel pump has three functions:
to deliver enough fuel to supply the requirements of an engine under all
operating conditions, to maintain enough pressure in the line between
the carburetor and the pump to keep the fuel from boiling, and to
prevent vapor lock. Excessive pressure causes the carburetor float
needle off its seat its seat resulting in high fuel level in the float
chamber, leading to high fuel consumption. Highest pressure occurs at
idling speed and the lowest at top speed.
Fuel Tank
The fuel tank stores the excess
fuel until it is needed for operation of the vehicle. The fuel tank has
an inlet pipe and an outlet pipe. The outlet pipe has a fitting for fuel
line connection and may be located in the top or in the side of the
tank. The lower end is about one-half inch above the bottom of the tank
so that collected sediment will not be flushed out into the carburetor.
The bottom of the tank contains a drain plug so that tank may be drained
and cleaned.
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