Chapter
n
Main
Structure
of
Diesel Engine
1.
Cylinder
head
Aassembly
Rl00
series diesel engines have the same kind of cylinder head with RI05 series
diesel engines.
Cylinder
head
is
a single piece casting structure, with independent intake,
and
ex-
haust ports
on
both sides. The intake port
is
a helicoid type designing.
In
order to de-
crease the heat load
of
cylinder head,
and
consider of the supercharged condition,
the cylinder
head
base wall theicknessis different at the
area
of valve distance'
and
injector seat hole,
and
cooled by inject cooling water. The valve guide and intake &
exhaust valve seats are interference fit with cylinder head very tightly. Valve seat ring
is
made of heat resisting
and
wear - resisting Chrome - molybdenum casting.
Intake
& exhaust valve and valve seat
have
been
run
-
in
when using,remember the
number of cylinder when disassembly
and
assembly. When sealing condition be-
tween valve
and
valve seat
is
not good, lapping
is
necessary,
and
should
be
clean be-
fore assembly. After long time operating,the width of valve seat contacting
area
may
be
over
2.
5
mm
,or
valver seat damaged or
non
- round, reaming should
be
done,or
change valve seat if necessary. When assembly,cylinder head should be heated at
a-
bout
2000C
,then the valve seat
can
be
in
- laid,after that ream
and
lap
it at the con-
tact
area
and
make it at
1.3
-1.5
mm
in
width,
valve setting value
is
0.6
...,
1.0
mm
down.
A copper - asbestos gasket
is
fitted between the cylinder
head
and
the cylinder
block. The cylinder
ead
is
tightened
on
the cylinder block by
18
(for
four - cylinder
diesel engine) or
26
(for
six - cylinder diesel engine) strengthen bolts
and
quenched
bolt gaskets.
The
cylinder
head
bolts should
be
tightened evenly by three times one
by one
in
regulated order
and
torque. (Fig.
1)
Fig.
1 The sequence of tightening cylinder
head
bolts
cyclinder head
of'
cylindor diesel engine
• 28 •
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