Table of Contents
Advertisement
ROCKER BOX COVERS - CYLIN-
DER HEADS - VALVES - GUIDES
- SPRINGS
Cylinder
heads,
in light alloy
,
are finned to
increa-
se coo ling surface.
Long
bolts,
short
bolts
and
nuts secure cylinder heads to crankcase.
STRIPPING
Removal
and stripping of cylinder heads
are
re-
quired when loss of
compression
is
noticed,
such
loss
being imputable to defective valve sealing,
and also after a certain period of operation,
in
order to
remove
carbon
deposits in
combustion
c
hamber.
When engine is
on
frame, cylinder heads strip-
ping Is carried Qut as follows:
Disconnect:
-
sparks
cables.
-
air inlet tubes and
carburetors.
-
exhaust
pipes and mufflers.
-
distributor cap
.
-
rocker box covers.
-
rocker arms and rocker arms supports.
Then remove cylinder
heads.
No difficulties are involved in
stripping
down cy·
linde
r
heads into parts. In any case all stripping
,
overhaulfng and assembling
operations,
and re·
quired tools, are lIsted
in the following para·
graphs:
REMOVAL OF SPRINGS AND VALVES
PositIon cylinder head on tool
No.
60907200 (see
7 on
Fig. 13)
and with
the
arm of same
press
on
the valve top
co
llar
so
to remove
semicones,
top
co llar,
spring, bottom plate and
,
from
inside
cy-
linder head, the
valve.
INSPECTION AND OVERHAUL
OF CYLINDER HEADS
Using a chamfered scraper
and
a wire
brush re-
move carbon
deposits
and Inspect
valve seats.
INSPECTION AND OVERHAUL
OF VALVE GUIDES
Valve guides are pressed in their housings in
cylinder
heads.
Removal
and
refitting are car-
ried out by means of a round punch
(see
Fig.
18
& 19).
Valve guide must be replaced
in case
of
excessive
lash
between
its
hole and the
valve
stem,
whenever
such lash is
not eliminable by
simply
replacing
valve.
After pressing guide
in
housing
,
hole must be
reamed
with
a straight reamer in order to bring
same to size as shown In
coupl
ing
data chart.
Negative
allowance in
pressing
guides in their
housings on cylinder heads, for both
inlet
and
exhaust valves. is to be
comprised
between
mm
.
0.046 and 0.075
(.0018
- .(0295).
16
•
f
r
fit
•
Fig.
18
Fig.
19
Fig.
19/1
Advertisement
Table of Contents
