User Manual
Chapter II Main Construction,
Adjustment and Maintenance
of
the
Di.esel
Engine
1.
Cylinder Block Assembly
Cylinder block
is
of a rectangle gantry type. Cylinder liners of
wet
type
are
fitted
in
the cylinder block
and
rested at its upper shoulder.
The
top surface of the liners
should
be
higher than the top surface of the block 0.03
-0.
08mm.
The
main bearing
caps
are
located
by
locating sleeves
and
machined
in
pair with the
corresponding bearing seats
on
the crankcase, so that the caps
can
"t
be
inter-
changed or turned inside out. Therefore, the bearing
cap
is
marked with number
and
arrowhead,
and
the direction of the arrowhead
.is
forward.
The
main
rod
bearing
is
made of steel - backed aluminum alloy which
is
very thin,
so
it cant
be
lapped.
Be-
fore installing,
we
should apply adequate clean engine
oil
on
the crankshaft.
There
are
two
bolts
on
one main bearing cap,
so
they should
be
tightened evenly
by
many times one
by
one
in
regulated torque,
and
should use tightening gaskets to
lock it.
In
the process of using, you shouldnt make the crankshaft receive additional power.
2. Cylinder
Head
Assembly
Cylinder
head
is
a single piece casting structure, with independent intake
and
ex-
haust ports
on
both sides.
The
combustion chamber
is
whirl chamber.
The
insert,
with a slant throat of kidney shape 'cross - section
and
a small comical hole inside,
is
pressed into the bottom of the swirl chamber.
·The
small conical hole should
be
a-
ligned with the
nozzle
center line
in
installation of the insert so
as
to make the
en-
gine easy' to start. Intake & exhaust valve
and
valve seat
have
been
run
-
in
when
u-
sing,
so
remember the number of cyli'nder when disassembly
and
assembly. When
sealing condition between valve
and
valve seat
is
not good, lapping
is
necessary,
and
should
be
cleaned before assembly. After long time operatiqn, the width of
valve seat contacting
area
may
be
over
2.
5mm,
we
can
ream the valve seat
by
means of a 15°and 75°special reamer with a guide
rod
of 9mm
in
diameter (Please
refer to
Fig.
1.
)
and
45°reamer articulated. contact
area
when necessary (ZH4100
intake valve seat ring should adopt
60
o
reamer) .
The
valve seat must
be
renewed if
the level of the valve
head
is
lower than ·that of the cylinder
head
bottom surface
by
more than
3.
5mm after the valve seat being reconditioned. Before a new valve seat
is
pressed into
th,e
cylinder head, a interference of
O.
086
-
O.
150mm
in
diameter
•
31
•