Crankshaft; Camshaft - Perkins 4008-30 SD8 Systems Operation, Testing And Adjustment

M0064276
Measure the bores in the connecting rod and ensure
that the bores meet the diameters according to the
correct specifications. When the connecting rod is
installed, follow the instructions for tightening the
bolts. Refer to Specifications, "Connecting Rod".

Crankshaft

The crankshaft changes the combustion forces in the
cylinder into usable rotating torque. A vibration
damper is used at the front of the crankshaft to
reduce torsional vibrations (twist) that can damage
the engine.
The crankshaft drives a group of gears that are on
the front of the engine. The gear group drives the oil
pump, the camshaft, the fuel transfer pump via the oil
pump, the water pump, and the auxiliary drives.
Seals are used at both ends of the crankshaft. The
seals are replaceable. Pressurized oil is supplied to
all main bearings through drilled holes in the webs of
the cylinder block. The oil then flows through drilled
holes in the crankshaft to provide oil to the
connecting rod bearings. The crankshaft is held in
place by nine main bearings. A thrust washer is
installed on either side of the rear main bearing. This
controls the end play of the crankshaft.
Note: The balance weights that are on the crankshaft
must not be removed. If a balance weight needs to
be replaced, the crankshaft must be returned to
Perkins.

Camshaft

There is one camshaft that runs through the cylinder
block. The camshaft is supported by nine bearings.
Oil is fed to the camshaft bearings from the main
gallery through the cylinder block. The camshaft is
driven by the gear group in a clockwise direction
viewed from the flywheel end.
As the camshaft turns, each lobe moves a lifter.
There are three lifters for each cylinder. Each outside
lifter moves a pushrod and two inlet valves or two
exhaust valves. The center lifter moves a pushrod
that operates the fuel injector.
The camshaft must be in time with the crankshaft.
The relation of the camshaft lobes to the crankshaft
position causes the valves and fuel injectors in each
cylinder to operate at the correct time relative to the
piston stroke.
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Basic Engine