Through the years,” boasted the 1980 full-line catalog. “Cadillac has earned for itself an exclusive place … a solitary niche … in the pantheon of the world’s truly fine automobiles.” Readers were even reminded how Cadillac had twice won the DeWar trophy in the early years of the century, first for its use of interchangeable parts and later, for pioneering the electric self-starter.
This year brought a restyled Brougham and DeVille, with a more formal roofline that gave more space in back. Their new grille was supposed to boost aerodynamic efficiency too. Flush-mounted windshields on Eldorado and Seville added style and helped cut wind noise. Suspension refinements included low-friction ball joints and larger bushings, plus new low-rolling-resistance tires. New options: a three-channel garage door opener and heated outside mirrors.
On the engine roster, the 368 cu. in. (6.0-liter) V-8 with four-barrel carburetor was standard on Fleetwood Brougham, DeVille and limousines. A digital fuel-injected version (with computerized self-diagnostic features) was standard on Eldorado, a no-cost option for Seville. The DFI V-8’s memory turned on an “Engine Check” light to warn of malfunctions. Meantime, the engine’s microprocessor could make substitutions that might allow the car to continue to run. An MPG Sentinel calculated continual. average and instantaneous miles-per-gallon readings at the touch of a button. Rounding out the lineup, Seville’s standard 5.7-liter diesel V-8, manufactured by Oldsmobile, was also available under the hood of Eldorado, DeVille and Fleetwood Brougham. Late in the model year, a Buick 4.1-liter V-6 was added — the first such offering on a Cadillac, and the first engine other than a V-8 in six decades.
Body colors for 1980 were: Cotillion White; Platinum; Sable Black; Steel Blue; Superior Blue; Twilight Blue; Canyon Rock; Princess Green; Blackwatch Green; Colonial Yellow; Flax; Sandstone; Columbian Brown; Bordeaux Red; Saxony Red; and Norfolk Gray. At extra cost, buyers could have any of five Firemist colors: Azure Blue, Desert Sand, Victoria Plum, Sheffield Gray. or Western Saddle. For rust protection, over 100 areas were specially treated. All lower body exterior panels were made from pre-coated metals. Each point of metal-to-metal contact contained either a gasket or bi-metal molding. All bodies were dipped in electrically charged primer to increase bonding adhesion.
While Brougham and DeVille got a moderate restyle for 1980, Seville changed drastically. Not everyone adored the new “bustleback” body and long hood, or the razor-edge contours reminiscent of 1950s Rolls-Royce bodies. The new Seville had front-wheel drive and, in a surprising move, a standard diesel engine. Sales dropped sharply, and would do so again in 1981, but these were bad years for the industry as a whole.
V.I.N. DATA
The last year for Cadillac’s 13-symbol Vehicle Identification Number (VIN) which was located on the upper left surface of the cowl, visible through the windshield.
Coding was similar to 1978-79.
The model year code changed to “A” for 1980.
Engine codes:
“8” 350 V-8 (fuel injection)
“6” 368 V-8 (four barrel carb)
“9” 368 V-8 (DFI)
“N” 350 V-8 Diesel
Assembly plant codes were:
“9” Detroit
“E” Linden, NJ (Eldorado only)
“C” South Gate, CA (DeVille only)
SPECIFICATIONS
FLUID CAPACITIES
Engine
V6 252cc (4.1L)
V8 350cc (5.7L)
V8 350cc (5.7L) Diesel
V8 368cc (6.0L)
Crankcase
4 qt
4 qt
6
4 qt
Crankcase with new filter
5 qt
5 qt
7
5 qt
AutomaticTransmission after draining
10 pt
10 pt
6 pt
8 pt
Drive Axle
3.25 pt
3.25 pt
4.25 pt
4.25 pt
Fuel tank
20 gal(US)
21 gal(US)
27 gal (US)
25 gal(US)
Cooling with heater
13.6 qt
15.5 qt
23.7 qt
21.4 qt
Cooling with A/C
13.6 qt
15.5 qt
23.7 qt
21.4 qt
Heavy duty Cooling
14.1 qt
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
11
Fuel pump pressure
4¼ to 5½ psi
5½ to 6½ psi
12 – 14 min.
Idle speed
550 rpm
575 rpm
575 rpm
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)
V8-350cc (5.7L)
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
12
Battery Terminal Grounded
Neg.
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
65 – 95
40 – 140
Starter, No-Lead Test, Volts
9
9
9
9
Starter, No-Lead Test, RPM
7000 – 10500
7000 – 10500
7000 – 10500
8000 – 13000
Starter, Brush Spring Tension
35 oz. min.
35 oz. min.
35 oz. min.
35 oz. min.
GENERAL ENGINE SPECS
Engine V.I.N Code
4
8
N
6
9
Engine type
V6-252cid(4.1L)
V8-350cc(5.7L)
V8-350cid(5.7L)
V8-368cid(6.0L)
V8-368cc(6.0L)
Manufacturer
Buick
Oldsmobile
Oldsmobile
Cadillac
Cadillac
Fuel delivery
4 bbl
EFI
Diesel
4 bbl
DFI
Horsepower
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Torque
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Bore x Stoke
3.965 x 3.400
4.057 x 3.385
4.057 x 3.385
3.800 x 4.060
3.800 x 4.060
Compression Ratio
8.00:1
8.00:1
22.5:1
8.20:1
8.20:1
Oil pressure
37 psi
35 psi
40 psi
35 psi
35 psi
CRANKSHAFT SPECS
Engine type
V6-252cc (4.1L)
V8-350cc(5.7L)
V8-350cc(5.7L) Diesel
V8-368cc(6.0L)
Main Brg Journal Dia.
2.4985
2.4985 – 2.4995(No. 1: 2.4988 – 2.4998″)
2.9993 – 3.0003
3.250
Main Brg Oil Clearance
0.0003 – 0.0018
0.0005 – 0.0021(No. 5 0.0015 – 0.0031in)
0.0005 – 0.0021(No. 5 0.0015 – 0.0031in)
0.0001 – 0.0026
Shaft End-play
0.003 – 0.009
0.004 – 0.014
0.004 – 0.014
0.002 – 0.012
Thrust on No.
2
3
3
3
CONNECTING ROD SPECS
Engine type
V6-252cc (4.1L)
V8-350cc(5.7L)
V8-350cc(5.7L) Diesel
V8-368cc(6.0L)
Journal Dia.
2.2487 – 2.2495
2.1238 – 2.1248
2.1238 – 2.1248
2.5000
Oil Clearance
0.0005 – 0.0026
0.0004 – 0.0033
0.0005 – 0.0026
0.0005 – 0.0028
Side Clearance
0.006 – 0.023
0.006 – 0.020
0.006 – 0.020
0.008 – 0.020
PISTON AND RING SPECS
Engine type
V6-252cc (4.1L)
V8-350cc(5.7L)
V8-350cc(5.7L) Diesel
V8-368cc(6.0L)
Piston-Bore Clearance
0.0013 – 0.0035
0.0010 – 0.0020
0.0005 – 0.0006
0.0006 – 0.0014
Ring Side Clearance: Top Compression
0.0030 – 0.0050
0.0020 – 0.0040
0.005 – 0.007
0.0017 – 0.0040
Ring Side Clearance: Bottom Compression
0.0030 – 0.0050
0.0020 – 0.0040
0.0018 – 0.0038
0.0017 – 0.0040
Ring Side Clearance: Oil Control
0.0035 max.
0.0006 – 0.0096
0.0078 max.
None (side sealing)
Ring Gap: Top Compression
0.013 – 0.023
0.010 – 0.023
0.015 – 0.025
0.013 – 0.023
Ring Gap: Bottom Compression
0.013 – 0.023
0.010 – 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
0.015 – 0.055
VALVE SPECS
Engine type
V6-252cc (4.1L)
V8-350cc(5.7L)
V8-350cc(5.7L) Diesel
V8-368cc(6.0L)
Seat Angle
45°
exhaust valve seat: 31°
intake: 45°;exhaust: 31°
45°
Face Angle
44°
exhaust valve face: 30°
intake: 44°;exhaust: 30°
44°
Spring Test Pressure
164 lb @ 1.34″(exhaust: 182 lb @ 1.34″)
187lb @ 1.27″
152 lb @ 1.30″
160 lb @ 1.50″
Spring Installed Height
1-11/32″
1-43/64″
1-43/64″
1-15/32″
Stem-to-Guide Clearance: Intake
0.0015 – 0.0035
0.0010 – 0.0027
0.0010 – 0.0027
0.0010 – 0.0027
Stem-to-Guide Clearance: Exhaust
0.0015 – 0.0032
0.0015 – 0.0032
0.0015 – 0.0032
0.0012 – 0.0029
Stem Diameter: Intake
0.3412
0.3429
0.3429
0.3420
Stem Diameter: Exhaust
0.3412
0.3424
0.3424
0.3418
TORQUE SPECS
Engine type
V6-252cc (4.1L)
V8-350cc(5.7L)
V8-350cc(5.7L) Diesel
V8-368cc(6.0L)
Cyl. Head Bolts
80 ft.lb
130 ft. lb
130 ft. lb
95 ft. lb
Rod Brg Bolts
40 ft.lb
42 ft. lb
42 ft. lb
40 ft. lb
Main Brg Bolts
100 ft.lb
80 ft. lb (No. 5: 120 ft. lb)
120 ft. lb
90 ft. lb
Crankshaft Damper or Pulley Bolt
225 ft.lb
310 ft. lb
200 – 310 ft. lb
Press fit
Flywheel to Crankshaft Bolts
60 ft.lb
60 ft. lb
60 ft. lb
75 ft. lb
Intake Manifold
45 ft.lb
40 ft. lb
40 ft. lb
30 ft. lb
Exhaust Manifold
25 ft.lb
25 ft. lb
25 ft. lb
long bolts: 35 ft.lb;short bolts: 12 ft.lb
CARBURETOR SPECS
Carb ID
17080230 (M4ME)
17080530 (M4ME)
Float Level
7/16 in
17/32 in
Air Valve Spring
1/2 turn
1/2 turn
Pump Rod
9/32 in
fixed
Primary Vacuum Break
0.149 in
0.142 in
Secondary Vacuum Break
0.136 in
0.400 in
Choke Rod
0.083 in
0.083 in
Choke Unloader
0.220 in
0.260 in
Fast Idle Speed
1450 rpm
1350 rpm
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
1980 Cadillac Notes
Introduced: October 11, 1979.
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 (U.S.): 231,028 for a 3.4 percent share of the industry total.
Calendar year Production (U.S.): 203,992.
Calendar year sales by U.S. dealers: 213,002 for a 3.2 percent market share.
Model year sales by U.S. dealers: 238,999.
This was not a top-notch year for Cadillac, as sales plummeted over 27 percent.
Production fell even further for the model year, down 39.4 percent.
The reason evidently was a declining eagerness for big cars, with rising interest in compact, fuel-efficient models.
In an attempt to meet these changing attitudes, Cadillac had reduced the size of the standard gasoline engine from its prior 425 cu. in. displacement down to a mere 368 cu. in. (6.0 liters).
Buick’s V-6 became optional late in the year.
But the division also speeded up production of the subcompact J-bodied Cimarron, originally intended for introduction in 1985.
Cadillac had problems meeting emissions control standards of the California Air Resources Board, whose restrictions had long been considerably stricter than the rest of the country.
The “standard” diesel on the new Seville wasn’t offered in California.
A new assembly plant for production of lightweight V-6 engines was announced at Livonia, Michigan.
Convertible conversions continued to be turned out by (among others) Hess & Eisenhardt in Cincinnati, which claimed to be the largest producer of Cadillac ragtops.
Their 1980 brochure displayed a Coupe DeVille conversion.