Ignition—Carburetion—Electrical
IGNITION TIMING
IGNITION TIMING:—Initial setting for fuel of 75 Octane rating. See Octane Selector for final setting.
Flywheel Degrees Piston Position
All Engines
10° BTDC
0442" BTDC.
To Set Timing (with Synchroscope)—Recommended
by manufacturer. Insert one Synchroscope lead in
# 1 terminal in distributor cap, clip second lead to
# 1 spark plug cable. Direct Synchroscope light at
flywheel through timing inspection hole In right
front face of flywheel housing above starter. Idle
engine at speed not greater than 400 RP.M. Note
position of flywheel timing mark 'ADV/'. If 'ADV
line does not coincide with line on housing, loosen
two distributor hold-down screws, rotate distributor
slowly until lines coincide, tighten hold-down screws.
Check position of Octane Selector pointer. If reference line on pointer does not coincide with center
line of scale, loosen pointer lockscrew, shift pointer,
tighten lockscrew.
NOTE—'ADV/' timing mark filled with paint.
To Set Timing (Without Synchroscope)—No means
provided to crank engine (engage gears and roll car
to turn engine over). With # 1 piston on compression, turn engine over until # 3 exhaust valve (fifth
valve from front of engine) begins to open, stop
when flywheel mark 'ADV/' lines up with mark on
flywheel housing (timing inspection hole in right
front face of housing above starter). Use timing
light or form spark gap between distributor high
tension lead and housing to check contact opening.
Loosen two distributor hold-down screws, rotate
distributor until contacts begin to open, tighten
hold-down screws. Check position of Octane Selector pointer. If reference line on pointer does not line
up with center line on scale, loosen pointer lockscrew, shift pointer, tighten lockscrew.
Octane Selector—Should be adjusted for final Ignition setting dependent upon Octane Rating of fuel
used by car owner. Initial setting (above) correct
for fuel of 75 Octane Rating. To adjust, loosen two
distributor hold-down screws, rotate distributor
clockwise so that pointer moves toward 'Low' end of
scale for fuel of lower rating, or counter-clockwise
(toward 'High' end of scale) for higher rating until
a slight 'ping' is noticeable at speeds between 10 and
15 MP.H. but not at higher speeds when car is accelerated with wide open throttle.
CARBURETOR
CARBURETION:—Carburetors—Stromberg Model AA-2
or Marvel Mod. BD-1S (No. 10-1751 std. air cleaner),
(No. 10-1752 heavy duty air cleaner). VA" dual
downdraft types. Stromberg aircraft type.
For complete data, refer to Carburetor Index.
Idle Adjustment—With engine warm, choke valve
wide open and engine idling at hot or slow idling
speed, adjust throttle stopscrew so that engine idles
at 7-8 M.P.H. Turn Idle adjusting screw for each
barrel (in succession) in until engine begins to lag
or miss, then turn screws out until engine begins to
roll, finally turn screws In slowly until engine fires
smoothly. Final setting should be 1V4 turns (Stromberg), %-% turns (Marvel) of screw from closed or
seated position. Readjust throttle stopscrew for
correct idling speed.
Accelerating Pump (Stromberg)—Two holes for
pump engagement. Set for maximum stroke unless
too rich a charge occurs on accelerating.
CENTURY 60, ROADMASTER 80, LIMITED 90
(Marvel)—Four holes for pump link engagement.
l—Minimum stroke—summer driving.
2—Interm. stroke—warm temperatures.
#3—Normal stroke—standard setting.
#4—Maximum stroke—winter driving.
Fast Idle:—Buick Cold Idle Control.
For complete data, refer to Carburetion Equip. Index.
Accelerator Linkage Adjustment:—Linkage adjustment must be maintained to provide correct throttle
opening for starting. With carburetor set for 7-8
M.P.H. Idling speed and throttle button pushed in,
rotate fast idle cam to extreme left against stop
(fast Idle position), adjust vacuum switch rod
length so that switch lever reference line lines up
with 'Fast Idle' line on housing. Check accelerator
pedal. Throttle should be wide open with pedal
down against pedal stop (floor mat). Adjust by
turning trunnion on accelerator rod. Accelerator
rod spring length should be 9 15/16".
Automatic Choke:—Delco-Remy Model 490-A (Stromberg Carburetors), 498-H, 1990001 (Marvel Carb.).
For complete data, refer to Carburetion Equip. Index.
Fuel Volatility Selector—Change setting as required
to provide correct choke action with fuel used.
Standard setting second notch from *Low' side of
scale (move toward 'high' end if mixture too rich,
toward 'low' end of scale if mixture too lean).
J
CARB. EQUIPMENT
Air Cleaner:—AC. #1526989 oil-wetted type standard.
#1528114 oil-bath optional.
NOTE—If heavy duty oil-bath type cleaner installed, main metering Jet (Stromberg), or power
jet and metering pin jet (Marvel) must be changed.
See Jet Specification Tables in Carburetor Section.
Fuel Pump:—AC. Type AB #1521838 (1st 10,000 cars)
combination fuel-and-vacuum pump. Type AK
#1523195 (after 1st 10,000 cars) fuel pump.
For complete data, refer to Carburetion Equip. Index.
Gasoline Gauge:—AC. Electric #1515321 (dash unit),
#1515444 (tank unit—60), #1515440 (80,90).
For complete data, refer to Carburetion Equip. Index.
BATTERY
BATTERY:—Delco, Type 15-G. 6 volt, 15 plate, 114 ampere hour capacity (20 hour rate).
Starting Capacity—137 amperes for 20 minutes.
Zero Capacity—300 amperes for 4.5 minutes.
Grounded Terminal—Negative (—) terminal.
Location—Under right front seat.
STARTER
Delco-Remy Model 727-W (Std.), 729-B (60 RHD).
Armature No. 820158.
Drive—Solenoid pinion shift & overrunning clutch.
Cranking Engine—115 RPM., 175 amps, at 5 volts.
Rotation—Counter-clockwise at commutator end.
Brush Spring Tension—24-28 ounces.
Performance Data
Torque
RP.M.
Volts
Amperes
0 ft. lbs
5500
5
65
16 "
Lock.
3
600
Removal:—Mounted on right front face of flywheel
housing. To remove, take out capscrews.
Starting Switch:—Solenoid Switch 1542 (727-W),
1545 (729-B), Vacuum Switch 1594, 1607. Solenoid
switch controlled through relay by vacuum switch
operated by accelerator pedal with ignition 'on'.
For complete data, refer to Electrical Equipment Index.
1937 B U I C K
Solenoid Switch Type 1542,1545
Closes against 70 lb. pull with y2" air gap drawing
65-71 amperes at 5 volts. Holds switch closed with
draw of 12-14 amperes (hold-in coll only).
Solenoid Relay
Contacts Close—1.9 volts max. Open—1.0-1.2 volts.
Contact Gap—.025-.045". Air Gap—.010-.013".
Vacuum Switch
Contacts Close—10-14° counter- clockwise (1594),
clockwise (1607), from latch position.
Unlatch Action—3.4-4.6" of HG. approximately 30°
from latch position.
GENERATOR
STANDARD
Delco-Remy Models 918-A, F. Armature 1866410.
New type 'Split-field' generator (one straight-shunt
coil, one third-brush coil—see wiring diagram) with
fixed third brush and vibrating voltage regulator
NOTE—Field coils changed In production.
For complete data, refer to Electrical Equipment Index.
Charging Rate Adjustment—Adjusted by changing
setting of voltage regulator. See Regulator data.
Maximum Charging Rate—As given in table below.
Reached at car speed of 46.5 (60), 44.5 (80), 41.9 (90)
M.P.H. (cold). To check charging rate, connect test
ammeter in line at 'BAT' terminal of regulator, voltmeter between 'GEN' terminal and ground, ground
*F' terminal to eliminate regulator action.
NOTE—Do not operate generator on open-circuit.
Performance Data
Amperes
Volts
RPM.
Cold
27-31
8.0
4000
Hot
25-28
8.0
4200
Rotation—Counter-clockwise at commutator end.
Brush Spring Tension—22-26 ounces (main), 16-20
ounces (third).
Field Current—Shunt (1.44-1.56 amperes at 6
volts), third brush (.89-.94 amperes at 6 volts.)
Removal:—Generator pivot mounted at left front of
engine. To remove, take out mounting screws.
Belt Adjustment:—Loosen clamp screw and pivot
screws, pull generator away from engine until belt
deflection midway between generator and fan pulleys is %" with light pressure.
GENERATOR
SPECIAL EQUIPMENT
Police Service—Delco-Remy Model 961-N. Armature
1857866 or 934-F, Armature No. 1861561. Two brush
type with voltage and current regulator control.
Charging Rate Adjustment—None. See Regulator.
Maximum Charging Rate—As follows:
Performance Data (Cold)
Amperes Volts R.P.M.
961-N
25.
8.0.
1650
934-F .
26
8.1-8.3
1325
Rotation—Counterclockwise at commutator end.
Field Current—2.0-2.2 amperes (961-N), 1.7-2.0 amperes (934-F) at 6.0 volts.
Brush Spring Tension—25 ounces each.
Mounting & Belt Adjustment:—Same as Std. (above).
REGULATOR
STANDARD
Delco-Remy Model 5807 (Std. Gen.). Double Core
Type Voltage Regulator (with IGN' Terminal). Cutout Relay and vibrating type voltage regulator In
CONTINUED ON NEXT PAOE