Cadillac Models & History 1978

Subtle exterior changes dominated 1978, as wheelbases and dimensions were virtually identical to 1977. DeVille, Brougham, limo and Eldorado had a bolder horizontal crosshatch grille. All but Eldorado had new rear bumper ends with vertical taillamps and three-dimensional crest insignia, Most broughams, all California Cadillacs and the fuel-injected DeVille sedan sported aluminum hoods. After the start of production, Elk Grain vinyl tops would be used on all except Seville, which retained a padded Tuxedo Grain vinyl top.

Passenger compartments had seven new interior colors and three new body cloths, including Random velour. Of the 21 body colors, 17 were new and all but two of those were exclusive to Cadillac. Signal-seeking AM/FM stereo radios were now standard on all Cadillacs. For the first time, chromed wire wheels from the British firm of Dunlop were offered as options on DeVille, Brougham, and Seville models. New electronic level control (standard on all except DeVille) used a height sensor to signal a motor-driven compressor that automatically adjusted for changing loads. The transmission had higher downshift speeds this year. DeVille and Brougham body mounts were retuned for a smoother, quieter ride. Four new special editions were offered:

  • Seville Elegante
  • Phaeton Coupe (or Sedan) DeVille
  • revised Eldorado Custom Biarritz.

An available diesel V-8 engine (built by Oldsmobile) for Seville was announced during the model year, at the Chicago Auto Show. So was a new electronic trip computer. All Cadillacs except Seville carried a standard 425 cu. in. V-8. Cadillac hardly tried to hide the boast that owning one had always “expressed success.” As the full-line catalog modestly proclaimed, “calling something ‘the Cadillac of its field’ is one of the finest compliments you can pay a product.”

For 1978, there were five models:

  • DeVille (two-door coupe and four-door sedan)
  • Fleetwood Brougham (four-door sedan)
  • Fleetwood Limousine (four-door sedan, four-door formal limousine, and commercial chassis used in hearses and ambulances, etc.)
  • Eldorado (two-door hardtop coupe)
  • Seville (four-door sedan)

I. D. DATA

  • Cadillac’s 13-symbol Vehicle Identification Number (VIN) again was located on the forward edge of the windshield trim molding, visible through the windshield.
  • Coding was similar to 1978.
  • The model year code changed to “S” for 1978.
  • Engine coding was now as follows:
    • “B” V8-350 EFI
    • “S” V8-425 4 Bbl.
    • “T” V8-425 EFI
    • “N” V8-350 diesel

SPECIFICATIONS

FLUID CAPACITIES

Engine V8 350cc (5.7L) V8 425cc (7.0L) V8 350cc (5.7L) Diesel
Crankcase 4 qt 4 or 5 qt 6 qt
Crankcase with new filter 5 qt 5 or 6 qt 7 qt
AutomaticTransmission after draining 8 pt 8 or 10 pt 6 pt
Drive Axle 4.3 pt 4.3 or 4 pt 4.3 pt
Fuel tank 21 gal(US) 24 or 27.5 gal(US) 21 gal (US)
Cooling with heater 18.9 qt 19.8 or 24.3 qt 18.9 qt
Cooling with A/C 18.9 qt 19.8 or 24.3 qt 18.9 qt
Heavy duty Cooling NA NA NA

GASOLINE ENGINE TUNE-UP SPECS

Engine V.I.N Code B S T
Engine type V8-350cc(5.7L) V8-425cc(7.0L) V8-425cc(7.0L)
Fuel delivery EFI 4 bbl EFI
Manufacturer Oldsmobile Cadillac Cadillac
Original Spark plug R47SX R45NSX R45NSX
Gap 0.060 in. 0.060 in 0.060 in
Distributor Electronic Electronic Electronic
Ignition timing (BTDC) 10° (8°) 18°@1400 rpm 18°@1400 rpm
Intake valve opens (BTDC) 22 21 21
Fuel pump pressure 5¼ to 6½ psi 5¼ to 6½ psi 39 min.
Idle speed 600 rpm 650 rpm 650 rpm

ALTERNATOR AND REGULATOR SPECS

Part # 1102380 1101023 1101033 1117152
Field current @ 12 V 4 – 4.5 4 – 4.5 4 – 4.5 4 – 4.5
Output 63 amps 80 amps 80 amps 145 amps
Regulator 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

BATTERY AND STARTER SPECS

Engine V8-350cc (5.7L) V8-425cc (7.0L) 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 – 12000
Starter, Brush Spring Tension 35 oz. min. 35 oz. min. 35 oz. min.

GENERAL ENGINE SPECS

Engine V.I.N Code B S T N
Engine type V8-350cc(5.7L) V8-425cc(7.0L) V8-425cc(7.0L) V8-350cc(5.7L)Diesel
Manufacturer Oldsmobile Cadillac Cadillac Oldsmobile
Fuel delivery EFI 4 bbl EFI Diesel
Horsepower [email protected] [email protected] [email protected] [email protected]
Torque [email protected] [email protected] [email protected] [email protected]
Bore x Stoke 4.057 x 3.385 4.082 x 4.060 4.082 x 4.060 4.057 x 3.385
Compression Ratio 8.00:1 8.50:1 8.50:1 22.0:1
Oil pressure 35 psi 35 psi 35 psi 40 psi

CRANKSHAFT SPECS

Engine type V8-350cc(5.7L) V8-425cc(7.0L) V8-350cc(5.7L)Diesel
Main Brg Journal Dia. 2.4985 – 2.4995 (No. 1 2.4988 – 2.4998 in) 3.250 2.9993 – 3.0003
Main Brg Oil Clearance 0.0005 – 0.0021″ (No. 5 0.0015 – 0.0031″) 0.0001 – 0.0026 0.0005 – 0.0021″ (No. 5: 0.0015 – 0.0031″)
Shaft End-play 0.004 – 0.014 0.002 – 0.012 0.004 – 0.014
Thrust on No. 3 3 3

CONNECTING ROD SPECS

Engine type V8-350cc(5.7L) V8-425cc(7.0L) V8-350cc(5.7L)Diesel
Journal Dia. 2.1238 – 2.1248 2.5000 2.1238 – 2.1248
Oil Clearance 0.0004 – 0.0033 0.0005 – 0.0028 0.0005 – 0.0026
Side Clearance 0.006 – 0.020 0.008 – 0.020 0.006 – 0.020

PISTON AND RING SPECS

Engine type V8-350cc(5.7L) V8-425cc(7.0L) V8-350cc(5.7L)Diesel
Piston-Bore Clearance 0.0010 – 0.0020 0.0006 – 0.0014 0.0005 – 0.0006
Ring Side Clearance: Top Compression 0.0020 – 0.0040 0.0017 – 0.0040 0.005 – 0.007
Ring Side Clearance: Bottom Compression 0.0020 – 0.0040 0.0017 – 0.0040 0.0018 – 0.0038
Ring Side Clearance: Oil Control 0.0006 – 0.0098 None (side sealing) 0.0078 max.
Ring Gap: Top Compression 0.010 – 0.023 0.013 – 0.023 0.015 – 0.025
Ring Gap: Bottom Compression 0.010 – 0.023 0.013 – 0.023 0.015 – 0.025
Ring Gap: Oil Control 0.015 – 0.055 0.015 – 0.055 0.015 – 0.055

VALVE SPECS

Engine type V8-350cc(5.7L) V8-425cc(7.0L) V8-350cc(5.7L)Diesel
Seat Angle 31°(exh) 45° intake: 45°; exhaust: 31°
Face Angle 30° (exh) 44° (exh) intake: 44°;exhaust: 30°
Spring Test Pressure 187 lb @ 1.27 in. 160 lb @ 1.50 in. [email protected]
Spring Installed Height 1-43/64″ (1.671875″) 11516 in. 1-43/64″
Stem-to-Guide Clearance: Intake 0.0010 – 0.0027 0.0010 – 0.0027 0.0010 – 0.0027
Stem-to-Guide Clearance: Exhaust 0.0015 – 0.0032 0.0010 – 0.0027 0.0015 – 0.0032
Stem Diameter: Intake 0.3429 0.3416 0.3429
Stem Diameter: Exhaust 0.3424 0.3416 0.3424

TORQUE SPECS

Engine type V8-350cc(5.7L) V8-425cc(7.0L) V8-350(5.7L) Diesel
Cyl. Head Bolts 130 ft.lb 90 ft. lb 130 ft. lb
Rod Brg Bolts 42 ft.lb 40 ft. lb 42 ft. lb
Main Brg Bolts 80 ft.lb (120 on # 5) 90 ft. lb 120 ft. lb
Crankshaft Damper or Pulley Bolt 310 ft.lb Press fit 200 – 310 ft. lb
Flywheel to Crankshaft Bolts 60 ft.lb 75 ft. lb 60 ft. lb
Intake Manifold 40 ft.lb 30 ft. lb 40 ft. lb
Exhaust Manifold 25 ft.lb 22 ft. lb 25 ft. lb

CARBURETOR SPECS

Carb ID 17058230 (M4ME) 17058232 (M4ME) 17058233 (M4ME) 17058533 (M4ME) 17058532 (M4ME) 17058530 (M4ME) 17058531 (M4ME) 17058535 (M4ME)
Float Level 13/32 in 13/32 in 13/32 in 13/32 in 13/32 in 13/32 in 13/32 in 13/32 in
Air Valve Spring 1/2 turn 1/2 turn 1/2 turn 1/2 turn 1/2 turn 1/2 turn 1/2 turn 1/2 turn
Pump Rod 3/8 in 3/8 in 3/8 in 3/8 in 3/8 in 3/8 in 3/8 in 3/8 in
Primary Vacuum Break 0.150 in 0.140 in 0.140 in 0.140 in 0.140 in 0.140 in 0.140 in 0.140 in
Secondary Vacuum Break 0.165 in 0.250 in 0.250 in 0.250 in 0.250 in 0.250 in 0.250 in 0.250 in
Choke Rod 0.080 in 0.080 in 0.080 in 0.080 in 0.080 in 0.080 in 0.080 in 0.080 in
Choke Unloader 0.230 in 0.230 in 0.230 in 0.230 in 0.230 in 0.230 in 0.230 in 0.230 in
Fast Idle Speed 1500 rpm 1400 rpm 1400 rpm 1400 rpm 1400 rpm 1400 rpm 1400 rpm 1400 rpm

WHEEL ALIGNMENT SPECS

Feature Eldorado Full size Seville
Caster Range 1°N – 1°P 2°P – 4°P 1°P – 3°P
Caster Pref. 3°P 2°P
Camber LH wheel Range ¾°N – ¾°P ¼°N – 1¼°P ¾°N – ¾°P
Camber LH wheel Pref. ½°
Camber RH wheel Range ¾°N – ¾°P ¼°N – 1¼°P ¾°N – ¾°P
Camber RH wheel Pref. ½°
Toe-In 0″ 0″ 1/16″
Steering Axis Inclination 10-19/32° 10-5/8°

HISTORICAL NOTES

1978 Cadillac Notes

  • Introduced: September 29, 1977.
  • Edward C. Kennard was general manager
  • Robert J. Templin was chief engineer
  • Wayne Kady was chief designer (Cadillac Studio)
  • F. T. Hopkins was general sales manager until March
  • L. B. Pryor became general sales manager in March
  • Model year production (U.S.): 349,684 for a 3.9 percent share of the industry total and the second highest Cadillac total ever.
  • Calendar year production (U.S.): 350,761.
  • Calendar year sales by U.S. dealers: 350,813 for a 3.8 percent market share.
  • Model year sales by U.S. dealers: 347,221.
  • Record sales greeted Cadillac for the third year in a row.
  • The model year total beat 1977’s mark by 6 percent.
  • The new Seville diesel (engine built by Oldsmobile) sold only about 2,800 copies, barely half the early prediction.
  • But it was introduced late in the model year.
  • Sevilles in general hit a new production high.
  • Eldorado did well also, as buyers snapped up the last of the vast Eldos before the 1979 downsizing.
  • A three-month shutdown of the Linden, New Jersey plant, to tool up for the new E-body 1979 Eldorado, Toronado and Riviera models, contributed to a loss in calendar year production of DeVilles this year.
  • Cadillac asserted that the company “consistently leads all U.S. luxury car makes in repeat ownership. Once you own a Cadillac,” they suggested, “it is difficult to accept anything less.”
  • Cadillac production figures
Sedan de Ville88,951 (decreased 6,470)
Coupe de Ville117,750 (decreased 21,000)
Eldorado46,816 (decreased 528)
Seville56,985 (increased 11,925)
Series 6036,800 (increased 8,800)
Series 752,382 (decreased 1,531)

1978 Automotive Notes

  • The “Big Four” produce nearly nine million cars
  • Sub-compacts account for 10% of domestic sales while compacts are nearly 28%
  • Corporate Average Fuel Economy (CAFE) standard becomes effective
  • A gas-guzzler tax is enacted
  • Firestone recalls 7.5 million 500-series steel-belted radial tires
  • Automotive news magazine estimates that federal requirements have added $519.65 to the price of a car between 1968 and 1978
  • GM news:
    • Thomas A. Murphy was chairman of the board at GM
    • Elliott M. Estes was president of GM
    • Impala/Caprice is year’s best seller
    • Chevette is best-selling US sub-compact
    • Chevrolet outsells Ford by over 450,000, followed by Oldsmobile, Pontiac, and Buick
    • GM’s mid-size cars are downsized, but the new “Aeroback” (fastback) models don’t sell well
    • GM drops the Vega and Astre
    • Cadillac introduces “Tripmaster,” a travel computer to register elapsed time, fuel mileage, etc.
    • Buick introduces the LeSabre Sport Coupe with a 150/165-bhp turbocharged V-6
    • Buick’s mid-size cars include a down-sized Century and Regal, but the Regal outsells the Century
    • Corvette has a new fastback roofline with a huge rear window; 6200 Indy 500 Pace Car Replicas and 2500 Silver Anniversary editions are produced
    • Last year for the 4-4-2 nameplate until 1980s revival
    • Full-size Oldsmobile gets a diesel V-8 or Buick’s 231-cid (3.8) V-6 options
    • Pontiac adds a fastback and wagon version of the Sunbird
    • LeMans is downsized to a 108-inch wheelbase
    • Pontiac Ventura is replaced by the Phoenix
  • Ford news:
    • New compact Fairmont and Zephyr are built on the “Fox” platform which will become the basis for many future Fords
    • Ford drops the Maverick and Comet
    • Henry Ford II fires Lee Iacocca from presidency
    • 1971-76 Pintos are recalled because of propensity to catch fire in rear-end collisions
    • Final year for the big LTD
    • Mustang II “King Cobra” gets a 302-cid (5.0 litre) V-8 option
    • On its 75th anniversary, Ford issues a Diamond Jubilee Thunderbird
  • Chrysler news:
    • In 7th and 8th place, Plymouth and Dodge drop behind Mercury in sales
    • Chrysler introduces first domestic built front-drive subcompacts: Dodge Omni and Plymouth Horizon with 1.7-litre VW engines
    • Dodge drops the Royal Monaco, Plymouth drops the Gran Fury
    • Last year for the Dodge Monaco and Plymouth Fury
    • Chrysler hires Lee Iacocca
    • Last year for the 440-cid (7.2 litre) V-8, the 400 (6.6 litre) V-8 is standard except in LeBaron
    • LeBaron engine choices are the Slant Six, 318-cid (5.2 litre) V-8, or 360-cid (5.9 litre) V-8
    • Magnum XE joins Dodge’s Charger SE. 400-cid (6.6 litre) V-8 is top engine option
  • AMC news:
    • AMC drops the Hornet name, but facelifts the model calling it Concord
    • Last year for the Gremlin
    • Last year for the Matador
  • Other makes news:
    • Volkswagen of America produces front-drive Rabbit in Pennsylvania
  • Top American Automobile Corporations for 1978


1. General Motors5,444,492
2. Ford2,728,326
3. Chrysler1,322,878
4. AMC137,860
5. Others728


  • Top model year production for 1978
Chevrolet2,375,436
Ford1,923,655
Oldsmobile1,015,805
Pontiac900,380
Buick803,187
Skyhawk24,589
Skylark114,220
Century87,746
Regal236,652
LeSabre171,932
Estate Wagon25,964
Electra 225121,549
Riviera20,535
Mercury635,051
Plymouth501,129
Dodge467,720
Chrysler354,029
Cadillac349,684
Seville56,985
DeVille206,701
Eldorado46,816
Fleetwood Brougham36,800
Fleetwood Limousine2,382
Lincoln169,620
AMC137,860
Gremlin22,104
Concord117,513
Pacer21,231
AMX2,540
Matador10,576
Checker300
Excalibur263
Avanti II165