----------
PART
1 - ENGINE
SYSTEMS----------
CRANKSHAFT
ASSEMBLY
The
crankshaft is supported
in
the cylinder
block
by
5 main bearings on the 4 cylinder en-
gine and 7 main bearings, on the 6 cylinder
engine.
Two
types
of
material are used
in
the manu-
facture
of
the
crankshafts:-
Nodular Iron, that has rough cast crank
webbs, for the 5640 & 6640 models and Steel
Crankshafts, · that have machine finished
crank webbs,
0
for the larger models. ·
End thrust is controlled
by
a thrust bearing in-
corporated in the centre main bearing of the
crankshaft.
A crankshaft driven dynamic balancer is in-
stalled on the 4 cylinder engines to ensure
smooth running performance during their
working life.
The
balancer assembly is bolted
to the bottom of the cylinder block and con-
tains two meshing weighted gears. These are
driven and timed from a
gear
heat shrunk to
the crankshaft.
In
addition to the internal balancer, a damper
is also fitted externally to the crankshaft pul-
ley.
The
six cylinder engine requires only this
external
damper
to ensure smooth running
operation. Front and rear crankshaft oil se~l-
ing is effected
by
one piece seals that are de-
signed for long and durable service life.
CONNECTING
RODS
Connecting rods "Teepee" (wedge) shaped
at
the small end have been designed to re-
duce the reciprocating weight at the piston
end. The connecting rods are
of
a heavy
beam
construction and are assembled as a
matched set to each engine, attached to the
crankshaft,
by
means of insert-type copper/
lead
or
aluminium tin alloy bearings.
They
are retained in position
by
the connect-
ing rod big end cap and secured
by
two bolts
per
rod. The small end of the connecting rod
is fitted with a replaceable bronze bushing,
through which the free floating piston pin is fit-
ted.
The
steel pin being held in place within
the piston
by
two snap rings.
PISTONS
Pistons of increased weight and strength, are
constructed
of
an aluminium silicon alloy with
an iron insert for the top ring. The combustion
chamber
being recessed into the piston
crowns.
Each piston has two compression rings and
one oil control ring, to reduce friction and in-
crease positive sealing. All rings are located
above the· piston pin.
2
MANIFOLDS
The cross flow design aluminium intake, and
cast iron exhaust manifolds, are on opposite
sides of the cylinder head. This is designed to
maintain balanced heat distribution within the
cylinder head. The configuration of the mani-
folds also ensures minimum heat transfer to
the intake manifold.
The intake manifold is connected through
tubing to the air cleaner and in the rear end of
the manifold a tapped hole is provided for in-
stallation of a thermostart
or
an
ether
cold
starting aid.
NOTE:
On tractors where
cold
start
equipment
is
not
installed ensure the
plug
in
the intake
manifold
is
kept
tight
at
all
times.
Considerable
damage
to
the cylinder bores,
may
be
incurred
by
entry
of
grit
or
other
foreign material
if
the
plug
is left loose
or
missing.
Also
dirt
and
grit
may
be
drawn
through the
air
cleaner connections
if
they
are
not
properly
secured.
CYLINDER BLOCK ASSEMBLY
The cylinder block is an alloy cast iron with
deep cylinder skirts, and water jackets for
cooling the cylinders. The cylinder bores are
machined integral with the cylinder block,
during the manufacturing process.
Cylinders are
in
line and vertical and num-
bered from 1 to 4
or
6, from the front to the
rear of the engine. They can be bored over-
size for the fitment of sleeves
or
oversize pis-
tons, which are available in service.
The oil pan which is attached to the bottom of
the cylinder block, is the reservoir for the en-
gine oil lubrication system. An aluminium en-
gine front cover is attached to the front engine
adapter plate and covers all of the timing
gear
assembly.
TIMING GEARS
The crankshaft timing
gear
is heated and
press fitted on to the front of the crankshaft, to
a high degree of accuracy during manufactur-
ing. This enables precise timing being main-
tained during the life of the engine.
The crankshaft
gear
drives the camshaft idler
gear which is attached to the front of the cylin-
der
block. The idler
gear
then drives the cam-
shaft and the injection pump via meshing heli-
cal gears.
The camshaft
gear
is bolted to the front
of
the
camshaft, and is keyed to maintain position of
the
gear
on the camshaft. All gears can
be
checked for timing by observing the punch
marks on the gears.
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