engine SKODA 120L 1980 User Guide

Fig.2.3/6
-
Position of Cylinder Liners,
Pistons
ond Connecting Rods in Engine
1 -
Proiectlon of cylinder liners
obove the top
foce of the cylinder block (0.125 -
0.155 mm)
2 -
Connecting rod splosh hole
'3
- Arrow on the piston
heod pointlng
toword
the comshoft
4 -
Comshoft
Fig.2.317 -
Pilot Ring
for Piston Rings
Dimensions of pilot
ring to motch cylinder
liner diometer:
dio. 68 D:68 H 7
dio. 68.25 D :68.25
H 7
dio. 68.50 D :68.50
H 7
dia. 72 D:72 H7 14.
Hoving fitted the piston
rings ond con-
nectlng rods on the pistons,
turn the piston
ring
gops so thot they ore stoggered
through 120o.
Coot the entire surfoce of the piston
with the
fitted rings with oll ond insert the pistons
ossembled with the connecting rods into the
liners in the sequence of the corresponding
numbers of cylinders ond connecting rods. Moke
sure thot the
orrow in the piston
heod points
toword the morking
of the cylinder liners, l.e.
toward the comshoft, ofter the ossembly with
the cylinder block. This
is importont in thot it
does owoy with odditionol turning of the pis-
tons in the liner ond o posslble
displocement
of the piston
ring gops.
Smeor the top surfoce of the cylinder block
with point
or o seoling
compound before
instol-
ling the liners with the pistons
ond connectlng
rods into the cylinders in the order of their
numbering. It is odvisoble to prepore
o sheet sleeve or
o pilot
ring occording to Fig. 2.317
to com-
press the piston
rings when fitting
the piston
Into the cylinder liners. Force the piston
into
the sleeve or pilot
ring so
thot the piston
heod
is flush with its edge or protrudes
sllghtly
over it, locote the piston
on the liner, ond then
force down the piston
through the sleeve or
pilot ring into the liner.
15. Ploce suitoble ouxiliory devices over two
holes for
cylinder heod bolts, for exomple
lorge-diometer woshers, ond screw them down
Fig. 2.3/8 -
Fitting Piston into
Cylinder Liner
Using the Pilot Rlng
1 -
pilot ring
2 -
cylinder liner
32

primory
feed to the distributor coincides with
the connecting line of the
distributor centre
line ond the first cylinder
heod
bolt os
per
Fig.2.3l10. Secure the distributor in this pos-
ition by lightly tightenning the tie-bolt ond
remove the timing geor
cover from the cylinder
block. The used type of distributor is described
in Chopter 13.5.
Fig.2.3l10 -
Position of Distributor on Engine
-l - screw of primory power
feed
2 -
cylinder heod bolt
3 -
index line rnorking the position
of the
distributor ornr when cvlinder No. 1 f ires
24. Coot with oil the moting
surfoces of the
timing geor cover ond the cylinder
block, locote
the cover gosket
on the block,
oil the timing
choin ond the comshott worm geor.
Remove the
f lywheel powl
ond rotote the
cronkshoft through
360o so
os to bring tlre pistons
of the cylinders
No. 1 ond 4 to their TDC position
ogoin. This
position corresponds opproximotely
to the volve
geor position
when the cylinder No. 1 f ires (the
tips of the coms of
cylinder No. 1 ore turned
downword, owoy from
the engine). Lock the
cronkshoft in position by refitting ond tight-
ening the flywheel powl.
25. Turn
the distributor orm in the direction
of the
screw (1) in occordonce with Fig. 2.3110,
hold it down with the
finger in this position,
ond ref it the timing geor
cover on the cylinder
block. By sliding the worm geor
of the distribu-
tor drive into the comshoft worm geor,
the orm
is turned to coincide with the timing
mork for
cylinder No. 1
on the distributor housing. lf
there is no coincidence of the orm ond timing
mork, od just
the position
of the orm by
slightly
rototing the distributor.
lf the
misolignment of the distributor
ornr
ond the timinq
mork of the
cvlinder
No'1 is so greot
thot it connot be corrected
by rototing
the distributor, remove
the timing geor
cover,
rotote the distributor slightly ond repeot
the
entire procedure
of refitting the timing geor
cover. 26. Smeor the protruding
end of the cronk-
shoft ond the outer shoft end (stem)
of the
belt
pulley with oil, f
it the belt pulley,
the nespective
wosher, ond tighten the bolt. Bolt the
PumP
suction stroiner tothe cronkshoft centre beoring
ond use o spring
wosher under the bolt heod.
27. Bolt down the timing geor
cover using
spring woshers ond
cheese-heod bolts
(exclus-
ively) cnd f inolly fosten the timing geor
cover
in such o position
thot the contoct breoker
points open before the crronkshoft with
the con-
necting rod ond piston
hos ottoined the top
deod centre (TDC)
position (see
the lgnition
Timing Toble in Chopter 15.3).
For checking the ignition odvonce, on electric
power supply is required with o bulb connected
in o circuit with the distributor. this
circuit
being interrupted by the oction of the contoct
breoker. An odopted conventionol torch with o
metol
iocket con be
used with odvontoge for this
purpose. Remove the flywheel powl ond
set the re-
quired ignition odvonce by turning the cronk-
shoft with o screw'driver inserted into
the geor
ring ond propped ogoinst the cylinder block
f longe. Rotote the shof t onticlockwise o bit
more thon necessory ond
bock it off so os to
odiust the bocklosh of the timing geors
ond the
distributor drive geors.
oK 6ls
Fi9.2.3111- Lomp for Checking the Opening
of Contoct Breoker Points
-1 - torch complete with dry cell ond bulb
2 -
leod with olligotor clomp
3 -
botterv cell
4 -
torch coo
5 -
contoct spring
6 -
insuloting plote
7 -
electricol-contoct connection of the leod
with the
drv cell Con
using
torch.
the br
slowly
indico
A corr
is not
timing 28.L
beorin
Then f
while
oil sun
the thr
the tyl
see Cl.
shri n ks
of the
woter
move i
ively.
To Fit
Toppetr
25. r
remove
positior
sure thr
cylinder
cylinder nuts. F<
first bo
woteir p
oir clec
finol ti1
2.16.
Ploin
heod bo
which t
woshers
no wosl
heod bo
cy I i nder
the outs
hove to
of the rc
Tighte
broce or,
30. Sc
thermom
into the
cosing o
ofter ho
Use spri
thermost
cooted g
with the
with the
The th
should br
34

ilil
ll
I
Z,l
spring woshers under the pump
fostening nuts.
36. lnstoll the oil filter -
see Oil Filter in
Chopter 15.3.
37. Bolt the brocket ond the reloy lever
of the
occelerotor linkoge to the intoke monifold, Use
spring woshers to lock the bolts in position.
38. Locote the corburettor gosket, sheet
guord, onother gosket,
the insuloting wosher,
ond o third gosket (oltogether
three goskets
of
the some type) on the intoke monifold inlet
socket, instoll the corburettor,
ond tighten
it
down with nuts.
On 105 ond 120 l- engines, the sheet guord
must be fitted to the intoke monifold inlet
socket with o throttling spider, while 120 LS
engines must hove the possoge
unobstructed.
39. Smeor the boll pins
of the linkoge
ond
corburettor lever with greose
contoining molyb-
denum disulphide
ond mount on them the oc-
celerotor link (tie-rod).
Hold the link in pliers
ond slip securing clips over the heods.
Hook o spring on the shonk of the reloy
link-
oge boll pin
ond on the rib of the forehousing
on the corburettor.
40. Screw down the vocuum
control pipe
on
the corburettor (using
double-sided seoling
rings) ond slip on the rubber
hose connecting
the pipe
with the distributor vocuum control
unit. Secure the pipe
by bending the clip under
the nut of the intoke ond exhoust monifold.
To Refit Alternotor
41. Attoch the olternotor
brocket to the side
of the cylinder block while putting
ploin
woshers under
the nuts. Mount the olternotor
holder together with the engine mounting lug
on the bolt of the timing geor
cover ond the
front lug of the cylinder block.
Use self-locking
nuts for the bolts f ostening the olternotor
holder. Lock
the lower bolt of the lug by meons
of o spring wosher
ond nut. Using onother bolt,
bolt together the lug ond the brocket. lnsert
the tie-bolt from
the side
of the lug, slip on
o ploin
wosher ond tighten the nut. Fit the
short-circuit strip on the bolt ond lock it in
o position
porollel
with the olternotor brocket
by screwing
down the respective nut with
o ploin
wosher.
42. Put the olternotor into the holder,
ttrreod
in the bolt, ond screw down the nut with o ploin
wosher without tightening. Without tightening
the self-locking
nut, bolt the strut into the
brocket on the cylinder heod. Swing the olter-
notor toword the engine, fit
the V-belt ond,
while tensioning it, connect the olternotor with
the strut using o bolt, spring wosher ond nut.
At the some time, tighten the nut of the bolt
holding down the olternotor
in the
holder ond
the nut of the bolt connecting the strut with
the holder. For the belt slock odiustment see
Chopter 15.3. 43.
Fosten the second
engine mounting lug
using nuts with spring woshers.
To Fit Cylinder Heod, Air
Cleoner,
ond Sporking Plugs
44. Fit the cylinder heod
with cemented.on
gosket on the cylinder block ofter hoving slip-
ped o seoling ring ond o wosher on eoch bolt,
the some os in the cose of the push-rod
cover.
In oddition, fit the fuel pipe
holder on the reor
bolt ond hold it down by slightly tightening the
nut.
45. Fit the oir cleoner in position
ond fosten
it to the corburettor with o bolt using o seoling
ring ond wosher. Put o spring wosher
under the
nut on the brocket
ond screw down the nut on
the bolt of the cover without ony wosher.
46. Threod the fuel hose through its holder
on the cylinder heod ond use clips to fosten it
to the corburettor ond pump.
Adiust the most
suitoble position of the hose by rototing
the
holder ond then tighten the nut.
47. Attoch hoses connecting the oir cleoner
with the corburettor ond the oil filler neck.
When preporing
the cc for driving in winter,
instoll the winter
oir-intoke tube (hose) -
for
detoiled instructions see Chopter 15.3 "Air
Cleoner -
Winter Operotion".
48. Screw in the sporking plugs
with seoling
iings ond fit the ignition cobles. For the re-
commended types of sporking plugs
see Chopter
13.7.
The outlet on the distributor cop morked with
o notch is intended for
the coble
to cylinder
No. 1. The
remoining outlets ore.to be counted
clockwise ond in direct
order from 1
to 4 ond
the cobles will be connected to sporking plugs
in the order of numbers cost on the cylinder
heod beside the recesses for sporking plugs.
Plug Screws ond Lubricotion
System
Accessories
49. Plug the oil sump with the conicol screw
plug with its
seoling ring. In the cose of on
engine without the oil cooler, plug
the oilwoy
on the timing geor
cover with o screw plug
with o seoling
ring, ond the oilwoy ot the reor
end of the cylinder block with o pressure
switch. lf the socket for screwing down the
pressure switch is missing, instoll o new socket
together with its respective seoling ring.
lf on oil cooler is provided,
hoses ond o press-
ure switch should be
connected to the oilwoys
occording to Chopter 11.9.
Put the oil dipstick
with the f itted rubber ring
in its ploce.
For the type of the dipstick see
Chopter 2.17.
50. Using spring
woshers with the bolts,
screw down the flywheel
guorcl
ofter removing
36

5. Use
the MP 1'105 puller
for removing
cylinder liners from the
block. Turn the centre
bolts of the
iig to expond
the
iig iows in the
cylinder liner (ot
the top flonge of the liner)
ond pull
out the liner by turning the vwench.
6. Before removing the comshoft, lift owoy
the volve toppets. lf o
removol of the cylinder
heod is not considered, releose
the boll pins
of
the rocker orms, lift cwoy the push
rods, remove
the si'de cover of the push
rods, ond withdrow
the volve toppets.
2.5 BRAKE TEST
AND ENGINE
LUBRICATION SYSTEM DIAGRAM
Broke Tcst In view of
the very specific chorocter of
the test, especiolly with
regord to the speciol
testing eguipment,we do not intend to describe
the test procedure, restricting ourselves to
men'
tioning only the moin volues which the test is
supposed to verify. Volues indicoted in the
diogroms ore oppli'
coble to o new engine or on engine ofter o top
overhoul, which hos been
correctly run'in
by
running for o period
of obout 50 hours (2,500
km
trovelled). lf the engine is tested under other
conditions, the meosured volues must opprooch
the diogrom volues conformobly with the mech-
onicol condition of the engine.
ln diogroms, peok
performonce
volues ore
indicoted os meosured in complionce with the
CSw (Czechoslovok
Stote Standords) ond DIN
,CsNr
kwrotN'
1{J
I
20
r5t0 (Deutsche
Ingenieur Normen), i.e. with
oll oc'
cessoires reducing the gross engine
horsepower
(woter pump,
olternotor, oir
cleoner, exhoust
silencer). The
effective horsepower con
vory
with respect to the diogrom volues
within
o toleronce limit of
minus 100/s.
Every engine ofter
o top overhoul or reploce'
ment of individuol ports
of the cronk mech'
onism hos to be run'in exoctly like o
new
engine. Do
not forget to
drow your
customer's
ottention to this foct!
'",ffi15
NM
300 t000 som
t/n{a
5000 l/rnrn csilr
kwuril'
50
i
ilii Fig.2.5l2
-
Power Output ond Fuel Consumption
Diogrom -
Skodo 120 L engine
1- 3 see Fig.2.5l1
5000 t/mrn
Fig.2.511- Power Output ond
Fuel Consttmption
Diogrom -
Skodo 150
S
engine
1 -
power output, 2 -
torque, 3 -
specif ic fuel
consumPtion
k/SAE: h. p.
(SAE) 1/min :
r.P.m. Fig.2.513
-
Power Output ond Fuel Cons
Diogrom -
Skodo 120
LS engine
I
38 1- 3 see
Fig.2.5l1

For the
instol lotion of the engine on the test
bench, we indicote the dimensions
of the en'
gine flonge ond flywheel. During broking, the
engine qnd
the engine oil must
be properly
cooled to preclude
exceeding the oPtimum
service conditions, i. e. woter temperoture
ofobout
80 to 90oC, ond oil temperoture of 12O"C
moximum -
see Chopter 2.5,
porogroph 51.
Engine Lubricotion
The inner lubricoting oil distribution system
is shown in Fig.2.5/5.
6 DK .r5+9 2.6
cYL
The cyl
mochined
the cronl
ports, forr
ore mode
B locks fo
72 mm di
I i ners.
Oilwoys, I
o) Befo
o new cyl
ossembled
blow thror"
b) Coot
pound or p
the oilwoy
c) Likev
into the e
pound or p,
of the
cyli
one (of
lo
limits indi
Ports) to er
d) Tighte
ot cylinder
under it.
e) Foster
the cop of
Fosten the
with o bolt
Fig.2.611 ond
1 -
choin gre
plug, 3 -
iniel
relief volve,
with cop, 6 -
inlet from o
ptug, I
9
8
7
5t
Fig.2.515 -
Engine Lubricotion Diognom
Skodo 120 LS
engine hos,
in oddition, on oil cooler incorporoted between the punrp
delivery
broncir on the timing geor
cover ond the moin oilwoy (see
Fi9.11.9)
srlctionstroiner,2-pump,3-pressurereliefvolve,4-moinoilwoy,5-oil filter,6-by-poss
hole, 7- oil pressure
switch, 8-pulsotingchomber, 9- rocker orms, 10-connecting rod
splosh hole, 11 -
choin splosh screw
4
2
4 t-
oil I
?
?
I
;
t

2.6-2.7
seot in the cylinder block using o copper or
oluminium rod.
Reconditioning Recesses for
Cylinder Liner
Flonges
Before ossembling o used
cylinder block,
inspect ond cleorr thoroughly the moting
sur-
foces of the recesses for
cylinder liner f
longes.
lf chemicol ogents (petrol,
etc.) foil
to hove
the required
effect, or if the surfoces hove
been domoged
mechonicolly, use the MP 1-106
dresser, or the MP 1-157
iig with
universol guicc
rings.
Reconditioning of Comshqft Beorings
lf on oversize
comshoft is to be f itted (ex-
cessive beoring cleoronces in on otherwise
sound block), drive out the plug
on the reor
side of the cvlinder block ond reom
the beor-
ings to dimensions specif ied in the following
Toble:
-0.025To
Grind
For grir
shoft by t
between 1
'Ihe
reor
ond there
for detoils
beoring.
For grir
prepored
clomped t,
pins must
Externol Col
Nomir iourn
Stondord
1st regrin
2nd regrin
3rd regrin
Stondond comshoft
Diometer of beoring in cylinder block
mm
+0.02s
38.5
+0.021
Oversize comshoft lsg
l-
38s-
l-;- -0.041
-0.020
The numerical symbols of the beorings (
l-lll)
indicote the respective
front, centre, ond reor
beari ngs.
Close the newly
mochined bore with o new
plug ond seol
it with o dob of point.
A poor
seoling would result in oil leoking
from the
engine into the clutch.
When reboring the bore for
the comshoft,
observe the centre distonces of the cronkshoft
ond comshoft. Otherwise the timing choin will
be either too slock or too tout. For the correct
distonces see
Fio. 2.6/3. Reconditioning
of Volve Toppet Guides
lf there is on excessive cleoronce in the
guides (beorings) of the volve toppets,
it is
possible to recondition the guides
ond to re-
ploce stondord toppets by toppets
of o lorger
diometer. The centre line of the beorings
is per-
pendiculor (normol) to the seoting foce
of the
cylinder block. The relotive dimensions
of the
beoning ond toppet ore
specified in
the Toble
below: o
L_r
_-L1il I toi .ll
-t
QZt0.l -T-
zi
A'ry
@)
2.7 CRANKSHAFT
AND ITS ACCESSORIES
The cronkshoft hos three rnoin beorings ond
four cronkpin beorings. lt is o forging with sof t,
not hordened iournols. When
worn, it
must be
reground to dimensions os per
Toble for fitting
oversize big-end ond moin beoring shells
os
well os cn oversize guide
ring. Cronkshoft Beoring
(for
clutch shoft)
It will be driven or pressed
into the shoft
lubricoted with the recommended greose
with
its cover turned outword.
After its pressing-in,
odd odditionol greose
by forcing it into the
shoft bore behind the beoring.
Use the extroctor MP 1-109 for
the removol
of the
beoring. Diometer of comshoft
iournols
mm
_ =l__i tl
Volve Toppet Diometer
of Beoring
in Cylinder Block, mmToppet
Diometer
mm
Stondord
on;rsizt- 21
+0.021 21
-0.020
21.2 21.2-0.007
42 4th

{
Smoll End ond
Big End Alignment
A misolignment of the centre line
of the
smoll-end bush ond big-end beoring
or the bore
for the big-end
beoring shells must never ex-
ceed 0.03
mm per 'lO0
mm of the connecting
rod length. For checking
ond olignment use
the
MP 1-102 or 1-159 f ixture.
Insert the odiusting pin
into the fixture ond
set both its diol indicotors to
zero. Clomp the
connecting rod without shells
into the fixture,
threod the pilot
pin
in it, ond swing
down the
connecting rod. The recdings
of the diol indi-
cotors will
show ony misolignment of the
smoll
ond big end. The moximum misolignment must
not exceed 0.03
mm os olreody mentioned.
Check for misolignment in two plones by tilting
the diol indicotors.
Two pilot
pins ore supplied, one with o
di-
ometer of 20 rnnr. the
other with o diometer of
20.05 mm, to motch the gudgeon
Pins.
To Motch Connecting Rod
with Gudgeon Pin
ond Cronkshoft
With regord to the reciprocoting movement
of the piston,
the gudgeon pin must hove
the
smollest possible
cleoronce in the
connecting
rod small end (ony lorger cleorcnce results
in
pin knocking). Therefore
select from
severol
gudgeon pins
one which will
be o close running
fit in the smoll-end
bush. lf no suclr pin is
ovoiloble, reom
tlre bush but never exceed the
moximum toleronce limits.
An oversize buslr lros to be
reomed to o nom-
inol diometer of 20.05 mm. For
the respective
dimensions refer to
the Toble supplied with
gudgeon pins. The big"end
beorings
i:;hells)
inouta be
selected occording to the nominol
diometer of the cronkpin. The
shells lrove no
diometer ntorking
oncl hove to be identif !ed
by meosuring their woll thickness with o mi'
crometer.
Motching Big-end Beoring
shells
with Cronkpins
MotchingCronkpin o"|,,n"iifl",,l ro,u,on
nominol diometer
1 thick"ness
mm
mm mm
45 (stondord)
44.75 (1st
regrinding)
44.50 (2nd
regrinding)
44.25 (3rd regrinding)
44 {:lttr regrinding) 1.490
1.615
1.740
1.865
1 990 0.007
Numericol lderrtif icotion of
Connecting Rods
For better identificotion, {igures con
be
stomped on the bosses of
the connecting rod
big end ( see Fig 2 11
1) . The f igures corre-spond with
the
number of the respective
gVtin-
derwithwhich theconnecting rod
is ossembled.
When replocing o connecting rod,
provide the
new connecting rod
with its very some identi-
ficction numbel. Stomp
the figures os much
toword the for end of the boss os possible to
ovoid fouling the loterol guide foce.
2.12 CYLINDERS, CONNECTING RODS
AND PISTONS
o) Only o cylinder (liner)
ond piston of
equot
'
diometer ond the some toleronce closs con
be ossembled qs
s unit.
b) Theengine cs qn
ossembly unit con befitted
cnly with cylinder liners ond pistons
of the
some diometer, the pistons being
of the
some weight grnLtp.
The inclividuol cylinder'cnd-piston qssemblies
con be, however, of dif
ferent toleronce
closses. On the othe'r hond, connecting rods
of only the sqme weight group
con be used-
These ore the cc;tditions for
the correct op-
erotion of pistons in the
cylinders ond for the
correct boloncing of the cronk mechonism.
For detoils concerning dimensions (diometers),
toleronce closses (cylinder liners, pistons) ond
weight groups
(connecting rods ond pistons)'
refei to fhe chcpters deoling with
the
individuol
pc|rts"
To Assembie Cylinder Liner
with Piston
qnd Connectirrg Rod
1. Toke cylinder liners ond pistons with
motching dinrensions, i. e.
cylinder liners of the
some boie (they need
not be necessorily of the
scrme toleronce closs), pistons
of the some
cliometer <,nrl tcieronce closs
to motch those of
the cvlinclr:i iitrers
ond of the sonre weight, oncl
connectitrct rorls, of rtne of
tlle twtl weiglrt
cl roLr PS.
lti''
DK 1161 2.
1
OCCorl Selec'
cyl i nd
tolpro
the (
motch Son
pin or
gudge
in wh
suitob
bush.
Mor
respor
with v
meric<
Rod'.
3.L
the gr-
80"c i Sme
home
some
threod
Pin, o
circlip
on thr
pressi I
Fit
hole ir
the orr
4.F
or exp
detoils
the ri
groove
5- Pr
the crc
ond co
2.13 I
In or
ter ist ic
coms o
comsh<
c leoror
the cor
Volve '
with
lntoker
open be
close o
Fi,c 2.1211 -
Press'f ittirrg
of Gudgeon Pin into
Piston Usinq MP 1-i04
Drift
50

Alternoting
cylinder No. 1
cylinder No.3
cylinder No.4
cylinder No. 2 Adjust cleoronce
on
cylinder No.4
cylinder No.2
cylinder No. 1
cylinder No.3
Fi1.2.1312
-
Volve Cleoronce Adjustment link from the choin
front side ond fit the clip
from the reor with its open end pointing in
the
direction opposite to the choin movement.
Before storting work on the volve geor,
re-
move the oil sump (engine
bottom cover to
which the timing geor
cover is bolted, the suc-
tion stroiner being ottoched to the cronkshoft
centre beoring cover) ond lock
the cronkshoft
in position
in the oxiol direction by depressing
the clutch pedol,
if removol of the entire engine
is not intended for onother purpose.
For speciol
points of the removol refer to
Chopter 2.4.
2.14 WATER PUMP
Disossembly 1. Unlock the wosher of the belt pulley
nut,
remove the nut ond pull
off the belt pulley
using
the MP 1-120 puller (o
fixturre for
Skodo MB 1000
cors) or o universol puller,
for the bolts of which
it is necessory to
cut threods M 8 in the belt
pulley holes.
By pulling
off the belt pulley,
occess will be
goined to the nuts fostening the pump
to the
engine. The some procedure
holds good
when
dismontling the pump
ofter it hos been removed
from the engine.
2. Withdrow the keyfrom
the shoft ond, using
the drift MP 1-121, drive
or press
out the shoft.
Then lift owoy the
housing plote
from the
seoting foce of the pump.
3. Remove the circlip locking the outer boll
beoring in position.
Proceeding from the reor
side of the pump
housing, drive out the boll
beorings with their spocer tube, ond remove
the
rubber seoling rring
from the housing.
Reossembly 1. Smeor the rubber seoling ring with greose
ond insert it into the pump
housing.
Use the
MP 1-123 drift to drive home the inner boll
beoring (without
sheet guord) pocked
with
greose. When opplying the drift,
fit its guide
ring into the bore for the
oute,r boll beoring.
2. Fit the gosket
on the pump
seoting foce
ond ploce
the pump plote
with its cemented-on
gosket (focing outwords from the pump)
over it.
Fosten the plote
to the pump provisionolly
with
one bolt to prevent
the gosket
from being dom-
oged during the following ossembly
iobs.
Insert the rubber seol,
wosher, ond conicol
spring into the speciol (bokelite)
seoling ring
of the pocking glond.
Instoll the spring
with
its nose
into the hole in
the bokelite pocking.
Slip the ossembled pocking glond
on the shoft
with the spring toword the shoft geor,
ond drive
the shoft home into the pump
beoring, while
supporting the beoring with the MP 1-123 drift. Fig.2
4. Fit t
shoft ond
stolling th
in positior
it with gre
sheet guor
5. Top
t
lieve the r
@@@@
DK 1240
Fig.2.1313 -
Volve Arrongement in Cylinderr Heod
Block disks -
exhoust volves
White disks -
intoke volves
Timing Choin ond Timing
Geors
Modified chain and gears
fitted since October
1979 recognised by
squared gearteeth
and chain
with split rollers.
The timing choin hos no slock odiuster (ten-
sioner). A slock choin does not substontiolly
offect the volve geor
occurocy but its operotion
is noisy. Therefore
its correct length should
be
ensured either
o) by selecting o suitoble choin from o number
of choins ovoiloble -
try it on the timing
geors, o1r
b) by replocing the stondord comshoft geor
with on oversize geor
(with greoter
toler-
onces). The comshoft geors
ore groded
in
keeping with their progressive
size (tol-
eronces) into closses A, B ond C. With the
exception of
closs A, the closs morking
letters ore stomped next
to the punch
mork.
For trying, the choin con be disconnected
to ovoid removing ond refitting of the timing
geors. To recouple the choin, insert the coupling Fig.2.1t
52

6.
Complete the pump
ossembly by fitting
the
Stouffer lubricotor filled with
the recommended
greose.
2.15 ROCKER SHAFT AND ROCKERS
Assembly (on
Skodo 105 engine)
1. Instoll the lock ring, ploin
wosher, ond
spring wosher on the ro6ker shoft
with both
ends plugged.
Smeor the shoft with oil, fit the
rocker (with
its orm with the thrust foce de-
flected toword the next ossembled ports),
the
shim, the rocker support, ond the other
orm
def lected toword the support, i. e. the complete
rocker unit of cylinder
No. 1.
2. Then slip the spring,
the rocker, the sup-
port, the shim,
ond the next rocker, i.e.
the
complete rocker unit of cylinder
No.2, on the
shoft.
3. Threod on the spring ond, using the mirror
orrongement of the ossembled
rocker units,
instoll the rocker
units of the remoining
two
cylinders. Use o lock ring supplemented
with
o ploin
ond o spring wosher
to lock the os-
sembled ports
in position.
The rocker support of the cylinder No.4 must
be provided
with on oil hole
to provide
for the
supply of oil to the rocker shoft.
4. Compress
the springs
by holding down the
rocker orms ond lubricote
oll loterol contoct
surfoces with oil.
Assembly (on Skodo 120 L
ond 120 LS engines)
The rocker shoft is provided
with two od-
ditionol rocker supports fitted from
the outside
of the rocker units (the
shoft is longer), re-
plocing woshers obutting
on the lock rings.
For
the rest, the ossembly is identiccl
with the pro-
cedure described in porogrophs
1 to 4 obove.
NJote: Rocker orms
on the Skodo 120 LS en-
gine ore shorter (18.5
mm) thon those on the
Skodo -120
L ond Skodo 105 engines,
in order
to obtoin o higher rotio.
Disossembly
Remove the lock ring from the shoft
end ond
strike off the
entire volve nocker geor
from
the
shoft.
2.16 CYLINDER HEAD, VALVES
AND
SPRINGS
The cylinder heod is o costing of speciol grey
cost iron. The volve seots ond guides
ore cost
ond mochined directlv in tlre heod. The volves ore of different
diometers, the intoke volves
being lorger. Outer (exhoust)
ports
ore single,
oll remoinlng ore doubled, i.e. bifurcoted
ond
bronching to two volves in odioining
cylinders.
The centre exhoust port
bronches to the cyl.
inders No.2 ond 3, the neighbouring
intoke port
to the cylinders No. 1 ond 2, ond No. 3 ond 4.
The cylinder heod con be hondled
in the cor os
o unit. Of the individuol
iobs, only
the reploce-
ment of volve springs,
cotters, ond cylinder
heod bolts con be corried out with the engine
in. position in the cor. For oll the remoining
iobs, the
cylinder heod hos to be removed
from
the cor.
To remove
the volve springs,
screw out
the
sporking plugs ond, using o tommy
bor with
o curved end (steel
bor of obout 5 mm dio-
meter), broce
the volve to prevent
it from
sliding down into the combustion
chomber.
To Remove
Cylinder Heod from Engine
1. Let
the engine cool down before removing
the cylinder heod to preclude
worping of its
beoring surfoce.
2. Droin
the coolont into o cleon vessel (see
Chopter 15.13), detoch oll ports
connecting the
cylinder heod to the vehicle,
ond remove
oll
ports which ore likely
to obstruct the removol.
3. Remove the oir cleoner,
lift owoy
the
cylinder heod cover, ond remove
the nuts ond
bolts holding down
the cylinder heod (on
en-
gines of Skodo 120 L
ond 120 LS cors, two
bolts olso hold down
the end rocker
shoft sup-
ports) reversing the order of the numbers
in-
dicoted in Fig. 2.1611.
By pulling
the exhoust
monifold, disengoge the
cylinder heod ond lift
it owoy.
To Refit Cylinder
Heod on Engine
. 1.
Locote the cylinder heod gosket
on o per-
fectly cleon surfoce of the cylinder
block (cleon
Fi1.2.1611- Tightening Diogrom of Cylinder
Heod Bolts ond Nuts
For tightening torques see Chopter
1.8 the
cylinc
the oilwo,
structed c
Releose
once odjur
heod. lf nr
the rocker
2. Swin<
down the
porogroph
opply the
liminory o
the sequ€
(Fig. 2.16/
shoft suppr
3. Adjus
ter 2.13,
re
cleoner, rer
tighten oll
Cylinder Hr
Disossem
heod on o r
o support i
it does
not
o iob from
t
An exomple
1. Remove
the cosing
control, end
geor ofter
supports.
Fig.2Je
For holding
c
bolt M 8 scrt
rocker-shoft st
1 -
MP 1-113
v,
2 -
MP 1-114
v
Itl
I
I
/\.
-
( 3 r--{ 4)
\-/
\II
l
/
,/
t___v'
?,3
"'@-:lO
54

The rocker-shqft
support hos o poper
seol
preventing leokoge of the oil fed from the cyl-
inder block to the rockers vio the support. lf
o reody-mode seol (gosket
) is not ovoiloble,
moke it yourself
using poper
0.1 mm thick.
A thicker seol
is unpermissible os it
would
couse c distortion of the rocker shoft. The hole
in the seol
must coincide with the oil hole
of
the rocker.
Apply the seol
ond ref it the
exhoust ond in-
toke monifolds. For detoils see
Chopter 2.3.
porogroph 30.
6. Reinstoll the thernrostotic temoeroture
control cosing with its gosket
ond do not forget
to put
spring woshers under the nuts.
Note: When reossembling
the cylinder heqd
of on engine removed
from the cor, it is odvis-
oble to proceed
with the
iobs os
per
porogroph
5 ond 6 with the cylinder heod refitted
on the
engine to focilitote
the tosk.
lf the cylinder heod gosket
hos been reploced
with o new one, invite the customer to bring in
the cor ofter
trqvelling 500
to 1,000 kilometres
for o retightening of the cylinder heod ond
odiusting of the volve cleoronce. 3. To ensure o leokproof
cond ition of the
volves, grind
them in
with their seots
in the
cylinder heod.
Volve GuideS The volve guides
ore formed directly by the
cylinder heod motericl. lf reconditioning
is
necessqry, rebore the guide
hole ond press-fit
o bush.
Volve guide bushes ore not ovoiloble os
sporre ports. They
con be mode
individuolly oc-
cording to the following drowing. The
required
moteriol is grey
cost iron of 200
N/mmz (2O
kpl
mm2) tensile strength, in
Czechoslovokio cost
iron to specificotions of theCzechoslovokSton-
dord CSN 422421.
Hoving press-fitted
the bush, correct ony
shrinkoge of the inside diometer ond, to motch
the new guides, rrecondition
the volve seots
ond grind-in
the volves.
DK 1+J6 Fig.2.16l
To Recon
These
volves fo
groph 3),
new volvt
Use o
conicol sr
with its r
1. Che
necessory
volves. F
shonk of,
eter, ond
will result
ing in ocr
seot widtl
Check 1
occordinq
Coot the"s
volve in tl
troces of
centre of t
2. Coot 1
volve with
of oil with
volve into
seot ond
1
severof tin
onother po
round the I
volve ond
grinding-in
the volve
c
grey. Use
down the v
Fi1.2.1613
-
Reconditioning Cylinder Heod
for Fitting Volve Guide Bush
Seoling of
Cylinder Heod
As o seporote unit or forming
o unit with
the cylinder block,
the cylinder heod
must be
seoled ogoinst leokoge
of goses
ond woter, i.e.
it must be gos-
ond wotertight.
1. When replocing
some of the bolts pro-
truding into the woter
iocket, seol
them
with
point. The woter
iocket of the
cylinder
heod
must be leckproof
when tested with woter
under c pressure
of 0.5 Mpo (5
kg/cm2).
2. lf it is necessory
to restore the flotness
of t-he cylinder heod
moting surfoce,
,egiind
the
surfcce only to the leost possible
exte-nt so os
not to increose
the engine
compression rotio.Valve
guide
tolerances
Guide 7.94 -
HB +
O.O22
o.oo mm
lnlet Valve 7.94 -
F7
t 9 9?q .n-
+ 0.013
0.025
56 Fi1.2.1614
-
Volve Guide Bush x
1Tr9