Rolls-Royce
Silver
Shadow
&
Bentlev
7
Series
Workshop
Manual
Chapter
K
adjustment, the car should
be
run for the equivalent of
20
miles
(32
km.) followed by five minutes at idle
speed.
1.
With the engine running at idle speed and Neutral
or Park selected, switch the air conditioning system to
the full
COLD
position. Select maximum blower speed
and open the circular
facia outlets and the rectangular
outlet.
2.
Allow the engine to idle for a minimum period of
two minutes.
3.
Measure the ambient temperature outside the
car
and from the table given select the appropriate 'fast-
idle' speed.
4.
Using the refrigeration 'fast-idle' adjustment
screw situated in the
'B' bank carburetter lever
(see
Fig.
Dl),
set the engine to run at the appropriate
'fast-idle' speed.
Ambient
air
temperature 'Fast-idle'
speed
@.p.m.)
10°C. (50°F.)
1
280
12~8°C. (55°F.) 1 250
15~6°C. (60°F.) 1210
18~3°C. (65°F.)
1
170
21
"C. (70°F.)
1
140
24°C. (75°F.)
1
100
26.7"C. (80°F.)
1
060
29.4"C. (85°F.)
1
020
32~2°C. (90°F.) 990
35°C. (95°F.) 950
37~8°C. (100°F.) 920
Carburetters-To
set
Cars from Car Serial Number SRH
8742
and onwards
Having set the mechanical adjustments to the auto-
matic choke set the carburetters by carrying out the
following operations in the sequence given.
A.
Synchronise throttles and temporarily set idle
speed.
B.
Set full throttle stop.
C.
Check linkage clearances.
D.
Tune carburetters.
E.
Set cold start 'fast-idle'.
F.
Set the throttle damper plunger.
G.
Set the kick-down micro-switch.
Throttle synchronisation
Refer to Page
K19.
Full throttle stop
1.
Adjust the full throttle stop screw so that it
measures
0.350
in.
(8,89
mm.)
from the boss face
(see
Fig.
K21
diagram
W).
2.
Check that the clearance
(X
in
Fig.
K21
diagrani
A)
between the fixed stop and the lever is correct.
If
the clearance is
less
than that specified, the throttle
stop screw should be adjusted to give the correct
clearance.
Linkage clearance-To check
Refer to Page
K19.
Carburetter Tuning
Cars from Car Serial Number
SRH
8742
and onwards
Preliminary checks
Before tuning the carburetters the following checks
should be carried out.
1.
Check the distributor contact point gaps; clean
and
re-set
if
necessary. Renew the points if they are
badly damaged.
2.
Check the sparking plug gaps.
3.
Adjust the fixed throttle screw to give an idle
speed of
800
r.p.m. When setting the engine idle speed
the operation must be carried out by reducing from a
higher speed to
800
r.p.m. Using a dwell angle meter
set
tlie dwell angle to between
26"
and
28"
by means of
the adjustment screw
(see
Chapter M-Electrical
System).
4.
Check the ignition timing
(see Chapter
M-
Electrical System).
5.
Check that the choke stove pipe is not obstructed
(see Page
k28).
6.
Check that the entire induction system is com-
pletely free from air leaks.
7.
Ensure that the throttle butterfly valves are
synchronised, the full throttle stop screw is adjusted
and the linkage
c!earance is correct as described under
Carburetters-To set.
Tuning conditions
To ensure that the engine temperature and mixture
requirements are
stabilised, tuning must be carried out
in
accordance with the following setting cycle.
1.
Screw the volume screws fully in, then back off
14
turns.
2.
With
the carburetter dampers, suction chambers,
springs and pistons already removed to enable throttle
synchronisation to be checked, set the main jet screws
as follows.
Using special spanner
(RH
8050),
slacken the car-
buretter jet screw lock-nut then manipulate each
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