The biggest news for 1981 was actually an ’82 model: the new subcompact Cimarron, introduced in the spring. (More on that in the next section.)
The second biggest was the new variable-displacement gasoline engine, developed by the Eaton Corporation a standard in all models except Seville. Depending on driving conditions, the innovative V8-6-4 engine ran on four, six, or eight cylinders, switching back and forth as needed. The object, of course, was to conserve fuel in the wake of rising gasoline prices. A microprocessor determined which cylinders weren’t necessary at the moment. Then it signaled a solenoid-actuated blocker plate, which shifted to permit the rocker arm to pivot at a different point than usual. Therefore, selected intake and exhaust valves would remain closed rather than operate normally. Valve litters and pushrods traveled up-and-down in the normal manner, but unneeded valve pairs stood idle. When running on four, displacement grew back to eight as soon as you stepped on the gas to pass, demanding maximum power — an assurance to those who might wonder if a four-cylinder Cadillac powerplant was good enough. The system had been tested (and “Proven”) in over half a million miles of driving. Cadillac claimed that the “perceived sensation” during displacement changes was “slight.” because no shifting was involved.
Another feature: push a button and an MPG Sentinel showed the number of cylinders in operation; push again to see instantaneous miles-per-gallon. Though the principle was not new, having been experimented with during World War II, the new engine was hailed as a dramatic answer to the economy problem for large passenger cars. Expanded self-diagnostics now displayed 45 separate function codes for mechanics to investigate. Imaginative but complex, the V8-6-4 brought more trouble than ease to many owners and didn’t last long in the overall lineup. Although it lasted for only a year, limousines kept it for several years longer.
On another level, Buick’s 252 cu, in. (4.1-liter) V-6 engine, introduced late in the 1980 model year, continued for a full season as an economy option.
Cadillacs now carried an on-board digital computer capable of making 300,000 decisions per second. It could even provide continued operation of the car if critical sensors malfunctioned, making an instantaneous substitution — even turning to a built-in analog computer if the digital electronics collapsed. To improve emissions, the new Computer Command Control module used seven sensors to monitor exhaust, engine speed, manifold air pressure, and coolant temperature, then adjust the air/fuel mixture.
“Answering Today’s Needs with Tomorrow’s Technology” was the logical theme of the full-line catalog. Though technically impressive, 1981 was not a year of significant change beyond some new grilles and other cosmetic alterations. Oldsmobile’s 350 cu. in. diesel V-8 was available in all six models: Fleetwood Brougham coupe and sedan, Coupe and Sedan DeVille, Eldorado, and Seville. A new light went under the hood. Rust-prevention measures touched over 100 specially treated areas, including pre-coated metals. Overdrive automatic transmission was now available with the V-6 engine on Fleetwood Brougham and DeVille. A memory seat option returned the six-way power driver’s seat to one of two selected positions.
.I.N. DATA
All Cadillacs had a new 17-symbol Vehicle Identification Number (VIN), stamped on a metal tag attached to the upper left surface of the cowl, visible through the windshield.
The number begins with a “1” to indicate the manufacturing country (U.S.A.), followed by a “G” for General Motors and a “6” for Cadillac Division.
The next letter indicates restraint system:
“A” manual (standard)
“B” automatic.
Symbol five is a letter denoting car line and series:
“S” Seville
“B” Fleetwood Brougham
“D” DeVille
“F” Fleetwood limousine
“Z” commercial chassis
“L” Eldorado.
Digits six and seven indicate body type:
“47” 2-door coupe
“69” 4-door four-window sedan
“23” six-window, eight-passenger sedan w/auxiliary seat
“33” six-window formal limousine w/aux. seat and center partition; “90” commercial chassis (no body); “57” Eldorado coupe.
Next comes an engine code:
“4” V6-252 4-bbl.
“N” V8-350 diesel
“6” V8-368 4-bbl.
“9” V8-368 DFI.
The next symbol is a check digit.
Symbol ten indicates model year (“B” 1981).
Symbol eleven denotes assembly plant: “9” Detroit; “E” Linden, New Jersey (Seville/Eldorado).
The final six-digit production sequence number began with 100001 for Detroit-built models: 600001 (Eldorado) or 680001 (Seville) for those built in New Jersey.
An identification number for the V-6 engine was on the left rear of the block; on the V8-350, a code label was on top of the left valve cover and a unit number label atop the right valve cover.
Other engines had a unit number on the block behind the left cylinder head, and a VIN derivative on the block behind the intake manifold.
A body number plate on the upper horizontal surface of the shroud (except Seville, on front vertical shroud surface) showed model year, build date code, car division, series, style, body assembly plant, body number, trim combination, paint code, modular seat code, and roof option.
SPECIFICATIONS
FLUID CAPACITIES
Engine
V6 252cc (4.1L)
V8 350cc (5.7L) Diesel
V8 368cc (6.0L)
Crankcase
4 qt
6 qt
4 qt
Crankcase with new filter
5 qt
7
5 qt
AutomaticTransmission after draining
8 pt
6 pt
8 pt
Drive Axle
4.25 pt
4.25 pt
4.25 pt
Fuel tank
25 gal(US)
27 gal(US)
25 gal(US)
Cooling with heater
18.2 qt
23.7 qt
21.4 qt
Cooling with A/C
18.2 qt
23.7 qt
21.4 qt
Heavy duty Cooling
NA
NA
NA
GASOLINE ENGINE TUNE-UP SPECS
Engine V.I.N Code
4
6
9
Engine type
V6-252cc(4.1L)
V8-368cc(6.0L)
V8-368cc(6.0L)
Fuel delivery
4 bbl
4 bbl
DFI
Manufacturer
Buick
Cadillac
Cadillac
Original Spark plug
R45TSX
R45NSX
R45NSX
Gap
0.060 in.
0.060 in
0.060 in
Distributor
Electronic
Electronic
Electronic
Ignition timing (BTDC)
15°
18°
10°
Intake valve opens (BTDC)
16
11
16
Fuel pump pressure
4¼ to 5¾ psi
5½ to 6½ psi
12 – 14 min.
Idle speed
550 rpm in Drive; A/C 680
575 rpm
470 rpm Drive or Neutral
ALTERNATOR AND REGULATOR SPECS
Part #
1102921
1101040
1101046
1101050
1101091
Field current @ 12 V
4 – 4.5
4 – 4.5
4 – 4.5
4 – 4.5
4 – 4.5
Output
63 amps
70 amps
80 amps
100 amps
100 amps
Regulator
Solid state
Solid state
Solid state
Solid state
Solid state
Volts @ 75°
13.8 – 14.8
13.8 – 14.8
13.8 – 14.8
13.8 – 14.8
13.8 – 14.8
BATTERY AND STARTER SPECS
Engine
V6-252cc (4.1L)
V8-368cc (6.0L)
V8-350cc (5.7L)Diesel
Battery Ampere Hour Capacity
540 amps cold cranking power @ 0°F
Battery Volts
12
12
12
Battery Terminal Grounded
Neg.
Neg.
Neg.
Starter, Lock Test, Amps
Not Recommended
Starter, Lock Test, Volts
Starter, Lock Test, Torque
Starter, No-Lead Test, Amps
65 – 95
65 – 95
40 – 140
Starter, No-Lead Test, Volts
9
9
9
Starter, No-Lead Test, RPM
7000 – 10500
7000 – 10500
8000 – 13000
Starter, Brush Spring Tension
35 oz. min.
35 oz. min.
35 oz. min.
GENERAL ENGINE SPECS
Engine V.I.N Code
4
N
9
6
Engine type
V6-252cc(4.1L)
V8-350cc(5.7L)
V8-368cc(6.0L)
V8-368cc(6.0L)
Manufacturer
Buick
Oldsmobile
Cadillac
Cadillac
Fuel delivery
4 bbl
Diesel
DFI
4 bbl
Horsepower
[email protected]
[email protected]
[email protected]
[email protected]
Torque
[email protected]
[email protected]
[email protected]
[email protected]
Bore x Stoke
3.965 x 3.400
4.057 x 3.385
3.800 x 4.060
3.800 x 4.060
Compression Ratio
8.00:1
22.5:1
8.20:1
8.20:1
Oil pressure
35 psi
40 psi
35 psi
35 psi
CRANKSHAFT SPECS
Engine type
V6-252cc(4.1L)
V8-350cc(5.7L) diesel
V8-368cc(6.0L)
Main Brg Journal Dia.
2.4995
2.9993 – 3.0003
3.250
Main Brg Oil Clearance
0.0003 – 0.0018
0.0005 – 0.0021 (No. 5: 0.0015 – 0.0031in)
0.0001 – 0.0026
Shaft End-play
0.003 – 0.009
0.004 – 0.014
0.002 – 0.012
Thrust on No.
2
3
3
CONNECTING ROD SPECS
Engine type
V6-252cc(4.1L)
V8-350cc(5.7L) diesel
V8-368cc(6.0L)
Journal Dia.
2.2487 – 2.2495
2.1238 – 2.1248
2.5000
Oil Clearance
0.0005 – 0.0026
0.0005 – 0.0026
0.0005 – 0.0028
Side Clearance
0.006 – 0.023
0.006 – 0.020
0.008 – 0.020
PISTON AND RING SPECS
Engine type
V6-252cc (4.1L)
V8-350cc(5.7L) Diesel
V8-368cc(6.0L)
Piston-Bore Clearance
0.0013 – 0.0035
0.0005 – 0.0006
0.0006 – 0.0014
Ring Side Clearance: Top Compression
0.0030 – 0.0050
0.005 – 0.007
0.0017 – 0.0040
Ring Side Clearance: Bottom Compression
0.0030 – 0.0050
0.0018 – 0.0038
0.0017 – 0.0040
Ring Side Clearance: Oil Control
0.0035 max.
0.0078 max.
None (side sealing)
Ring Gap: Top Compression
0.013 – 0.023
0.015 – 0.025
0.013 – 0.023
Ring Gap: Bottom Compression
0.013 – 0.023
0.015 – 0.025
0.013 – 0.023
Ring Gap: Oil Control
0.015 – 0.035
0.015 – 0.055
0.015 – 0.055
VALVE SPECS
Engine type
V6-252cc (4.1L)
V8-350cc(5.7L) Diesel
V8-368cc(6.0L)
Seat Angle
45°
45°(intake); 31° (exhaust)
45°
Face Angle
44°
44°(intake); 30° (exhaust)
44°
Spring Test Pressure
164 lb @ 1.34″(exhaust: 182 lb @ 1.34″)
210 lb @ 1.30″
160 lb @ 1.50″
Spring Installed Height
1-11/32″
1-43/64″
1-15/32″
Stem-to-Guide Clearance: Intake
0.0015 – 0.0035
0.0010 – 0.0027
0.0010 – 0.0027
Stem-to-Guide Clearance: Exhaust
0.0015 – 0.0032
0.0015 – 0.0032
0.0012 – 0.0029
Stem Diameter: Intake
0.3412
0.3429
0.3410
Stem Diameter: Exhaust
0.3412
0.3424
0.3417
TORQUE SPECS
Engine type
V6-252cc (4.1L)
V8-350cc(5.7L) Diesel
V8-368cc(6.0L)
Cyl. Head Bolts
80 ft.lb
130 ft. lb
95 ft. lb
Rod Brg Bolts
40 ft.lb
42 ft. lb
40 ft. lb
Main Brg Bolts
100 ft.lb
120 ft. lb
90 ft. lb
Crankshaft Damper or Pulley Bolt
225 ft.lb
200 – 310 ft. lb
Press fit
Flywheel to Crankshaft Bolts
60 ft.lb
60 ft. lb
75 ft. lb
Intake Manifold
45 ft.lb
40 ft. lb
30 ft. lb
Exhaust Manifold
25 ft.lb
25 ft. lb
long bolts: 35 ft. lb; short bolts: 12 ft. lb
CARBURETOR SPECS
Carb ID
17081248 (M4ME)
17081289 (M4ME)
Float Level
3/8 in
13/32 in
Air Valve Spring
5/8 turn
5/8 turn
Pump Rod
fixed
fixed
Primary Vacuum Break
0.164 in
0.164 in
Secondary Vacuum Break
0.136 in
0.136 in
Choke Rod
0.139 in
0.139 in
Choke Unloader
0.243 in
0.243 in
Fast Idle Speed
See underhood decal
WHEEL ALIGNMENT SPECS
Feature
Eldorado
Full size
Seville
Caster Range
1½°P – 3½°P
2½°P – 3½°P
1½°P – 3½°P
Caster Pref.
2½°P
3°P
2½°P
Camber LH wheel Range
3/16°N – 3/16°P
3/32°P to 57/64°P
3/16°N to 3/16°P
Camber LH wheel Pref.
0°
½°
0°
Camber RH wheel Range
3/16°N – 3/16°P
3/32°P to 57/64°P
3/16°N to 3/16°P
Camber RH wheel Pref.
0°
½°
0°
Toe-In
1/8°P to 1/8°P
1⁄8 in.
1⁄8 in.P to 1⁄8 in.P
Steering Axis Inclination
11°
10-19/32°
11°
HISTORICAL NOTES
1981 Cadillac Notes
Introduced: September 25, 1980.
Edward C. Kennard was general manager
Robert J. Templin was chief engineer
Wayne Kady was chief designer (Cadillac Studio)
L. B. Pryor was general sales manager
Model year production: 253,591 (including 13,402 1982 Cimarrons built during the 1981 model year).
The total included 30,440 cars with V-6 engine and 42,200 diesels.
Calendar year production: 259,135.
Calendar year sales by U.S. dealers: 230,665 for a 3.7 percent market share.
Model year sales by U.S. dealers: 226,427 (including 8,790 Cimarrons built before September 1981).
Historical Footnotes: “Cadillac is class,” the full-line catalog declared, echoing a theme that had been used for decades.
“Class” seemed to take many forms by the 1980s.
In addition to the customary funeral/ambulance adaptations and stretch limos from various manufacturers, two conversions came from Wisco Corporation (in Michigan): a Renaissance Coupe DeVille and a Seville Caballero.
Cadillac production figures
Cimarron17,602
Fleetwood/de Ville series149,715 (increased 13,078)