1978 CHECKER

General Specifications:

Chasis:

Marathon:

Wheelbase: 120"

Overall Length: 204.8"

Tire Size: G78 X 15 Inches

Marathon DeLuxe

Wheelbase: 129"

Overall Length: 212"

Tire Size: G78 X 15 Inches

Rear Axle Ratio:

6 Cylinder Models: 3.07:1

8 Cylinder Models: 2.72:1

Body Data:

Checker Marathon Series:

6 Cylinder:

Model A12; 4 Door Sedan, 6 Passenger, Body #A12

Base Price: $6,419; Shipping Weight: 3,765 Pounds;

8 Cylinder:

Model A12; 4 Door Sedan, 6 Passenger, Body #A12

Base Price: $6,598 with 305 Engine.

Base Price: $6,741 with 350 Engine.

Shipping Weight: 3,862 Pounds;

Model A12; 4 Door DeLuxe Sedan, 6 Passenger, Body #A12E

Base Price: $7,472; Shipping Weight: 4,062 Pounds;

Engine Specifications:

6 Cylinder Engine, 250 Cu. In. 1 Barrel Carburetor, 110 HP:

Engine Type: Inline 6 Cylinder, Overhead Valve

Bore & Stroke: 3.875" X 3.53"

Engine Displacement: 250 Cu. In.

Compresssion Ratio: 8.2 to 1

Taxable Horsepower: 36.03

Horsepower: 110 @ 3,800 RPM

Torque: 195 Ft. Lbs. @ 1,600 RPM

Normal Oil Pressure: 36-41 Lbs/Sq. In

1Barrel Carburetor

8 Cylinder Engine-305 Cu. In., 145 HP:

Bore & Stroke: 3.736" X 3.48"

Engine Displacement: 305 Cu. In.

Compression Ratio: 8.50:1

Taxable Horsepower: 44.66

Horsepower: 145 @ 3,800 RPM

Torque: 245 Ft. Lbs @ 2,000 RPM

Normal Oil Pressure: 45 Lbs/Sq. In.

2 Barrel Carburetor

8 Cylinder Engine-350 Cu. In., 160 HP:

Bore & Stroke: 4.001" X 3.48"

Engine Displacement: 350 Cu. In.

Compression Ratio: 8.50:1

Taxable Horsepower: 51.22

Horsepower: 160 @ 3,800 RPM

Torque: 260 Ft. Lbs @ 2,400 RPM

Normal Oil Pressure: 32-40 Lbs/Sq. In.

4 Barrel Carburetor

Tune-Up Specifications:

6 Cylinder Engine:

Spark Plug Type: AC R46TS

Spark Plug Gap: .035"

Ignition Timing:

Without Air Conditioning: 10 Degrees BTDC

With Air Conditioning: 8 Degrees BTDC

Engine Idle Speed:

Automatic Transmission: 425 RPM in Drive (550 RPM w/idle solenoid energized)

Fast Idle Speed: 2,100 RPM

Fuel Pump Pressure: 4 to 5 PSI

8 Cylinder Engine, 305 Cu. In.:

Spark Plug Type: AC R45TS

Spark Plug Gap: .045"

Ignition Timing: 4 Degrees BTDC

Engine Idle Speed:

Automatic Transmission: 500 RPM in Drive

Fuel Pump Pressure: 7-1/2 to 9 PSI

8 Cylinder Engine, 350 Cu. In.:

Spark Plug Type: AC R45TS

Spark Plug Gap: .045"

Ignition Timing: 6 Degrees BTDC

Engine Idle Speed:

Automatic Transmission: 500 RPM in Drive (600 RPM w/idle solenoid energized)

Fast Idle Speed: 1,600 RPM

Fuel Pump Pressure: 7-1/2 to 9 PSI

Distributor Specifications:

Not Available. Use distributor number and refer to 1978 Chevrolet data for information.

Valve Specifications:

6 Cylinder Engines:

Valve Lash: Hydralic Lifters-1 Turn Down From Zero Lash

Valve Angles:

Seat: 46 Degrees

Face: 45 Degrees

Valve Spring Height, Installed: 1-21/32"

Valve Spring Pressure: 175 Lbs. @ 1.26"

Valve Stem Clearance:

Intake: .0010" to .0027"

Exhaust: .0010" to .0027"

Valve Stem Diameter:

Intake: .3410" to .3417"

Exhaust: .3410" to .3417"

8 Cylinder Engines:

Valve Lash: Hydralic Lifters-1 Turn Down From Zero Lash

Valve Angles:

Seat: 46 Degrees

Face: 45 Degrees

Valve Spring Height, Installed: 1-23/32"

Valve Spring Pressure: 200 Lbs. @ 1.25"

Valve Stem Clearance:

Intake: .001" to .0027"

Exhaust: .001" to .0027"

Valve Stem Diameter:

Intake: .3410" to .3417"

Exhaust: .3410" to .3417"

Pistons, Pins, Rings, Crankshaft, & Bearing Specifications:

6 Cylinder Engine:

Piston Clearance: .0010" to .0020"

Ring End Gap:

Compression: .010"

Oil: .015"

Wrist Pin Diameter: .9272"

Rod Bearings

Shaft Diameter: 1.9928" to 2.000"

Bearing Clearance: .0010" to .0026"

Main Bearings:

Shaft Diameter: 2.2979" to 2.2994"

Bearing Clearance:

#1-#6: .0010" to .0024"

#7: .0016"-.0035"

Thrust on Bearing #7

Shaft End Play: .002" to .006"

8 Cylinder Engine, 305 Cu. In.:

Piston Clearance: .0007" to .0017"

Ring End Gap:

Compression: .010"

Oil: .015"

Wrist Pin Diameter: .9272"

Rod Bearings

Shaft Diameter: 2.0986" to 2.0988"

Bearing Clearance: .0013" to .0035"

Main Bearings:

Shaft Diameter:

#1: 2.4484" to 2.4493"

#2, 3, 4: 2.4481" to 2.4490"

#5: 2.4475" to 2.4488"

Bearing Clearance:

#1: .0008" to .0020"

#2, 3, 4: .0011" to .0023"

#5: .0017" to .0033"

Thrust on Bearing #5

Shaft End Play: .002" to .006"

8 Cylinder Engine, 350 Cu. In.:

Piston Clearance: .0007" to .0017"

Ring End Gap:

Compression: .010"

Oil: .015"

Wrist Pin Diameter: .9272"

Rod Bearings

Shaft Diameter: 2.099" to 2.100"

Bearing Clearance: .0013" to .0035"

Main Bearings:

Shaft Diameter:

#1: 2.4484" to 2.4493"

#2, 3, 4: 2.4481" to 2.4490"

#5: 2.4475" to 2.4488"

Bearing Clearance:

#1: .0008" to .0020"

#2, 3, 4: .0011" to .0023"

#5: .0017" to .0033"

Thrust on Bearing #5

Shaft End Play: .002" to .006"

Engine Tightening Specifications:

6 Cylinder Engine:

Spark Plugs: 15 Ft. Lbs

Cylinder Heat Bolts: 95 Ft. Lbs. (Left Hand Front Head Bolt: 85 Ft. Lbs.)

Exhaust Manifold: 30 Ft. Lbs.

Rocker Arm Cover: 45 Inch Lbs.

Connecting Rod Cap Bolts: 35 Ft. Lbs.

Main Bearing Cap Bolts: 65 Ft. Lbs.

Flywheel to Crankshaft: 60 Ft. Lbs.

Vibration Damper or Pulley: 60 Ft. Lbs.

8 Cylinder Engine, 305 Cu. In.:

Spark Plugs: 15 Ft. Lbs

Cylinder Heat Bolts: 65 Ft. Lbs.

Intake Manifold: 30 Ft. Lbs.

Exhaust Manifold:: 20 Ft. Lbs.

Rocker Arm Cover: 45 Inch Lbs.

Connecting Rod Cap Bolts: 45 Ft. Lbs.

Main Bearing Cap Bolts: 70 Ft. Lbs.

Flywheel to Crankshaft: 60 Ft. Lbs.

Vibration Damper or Pulley: 60 Ft. Lbs.

8 Cylinder Engine, 350 Cu. In.:

Spark Plugs: 22 Ft. Lbs

Cylinder Heat Bolts: 65 Ft. Lbs.

Intake Manifold: 30 Ft. Lbs.

Exhaust Manifold:

Outside Bolts: 20 Ft. Lbs.

Inside Bolts: 30 Ft. Lbs.

Rocker Arm Cover: 45 Inch Lbs.

Connecting Rod Cap Bolts: 45 Ft. Lbs.

Main Bearing Cap Bolts: 80 Ft. Lbs.

Outer Bolts on Engines with 4 bolt caps: 70 Ft. Lbs.

Flywheel to Crankshaft: 60 Ft. Lbs.

Vibration Damper or Pulley: 60 Ft. Lbs.

Alternator Specifications:

Not Available. Use alternator number and refer to 1978 Chevrolet data for information.

Starting Motor Specifications:

6 Cylinder Engine:

Starter #1108774

Free Speed Test: 50-80 Amperes, 9 Volts @ 5,500-10,500 RPM

8 Cylinder Engine, 305 Cu. In.:

Starter #1109056

Free Speed Test: 50-80 Amperes, 9 Volts @ 5,500-10,500 RPM

8 Cylinder Engine, 350 Cu. In.:

Starter #1109052

Free Speed Test: 65-95 Amperes, 9 Volts @ 7,500-10,500 RPM

Rear Axle Specifications:

Information Not Available.

Brake Specifications:

Information Not Available.

Capacities:

Fuel Tank: 21.6 Gallons

No other information is available.

Wheel Alignment:

Information is not available.

Rochester Carburetor Specifications:

1 Barrel:

Carburetor #: 17058020

Float Level: 5/16"

Metering Rod: .100"

Choke Coil Lever: .120"

Choke Rod: .180"

Vacuum Break: .200"

Unloader: .500

Choke Setting: Index

2 Barrel:

Carburetor #: 17058108B

Float Level: 19/32"

Float Drop: 1-9/32"

Pump Rod: 1-21/32"

Intermediate Choke Rod: .150"

Vacuum Break: .160"

Automatic Choke Setting: Index

Choke Rod: .260"

Choke Unloader: .325"

4 Barrel:

Carburetor #: 17058504A

Float Level: 15/32"

Pump Rod Hole: Inner

Pump Rod: 9/32"

Fast Idle Turns on Bench: 3

Choke Coil Lever: .120"

Choke Rod: 46 Degrees

Vacuum Break: 31 Degrees

Air Valve Dash Pot: .015"

Automatic Choke Setting: 2 Lean

Choke Unloader: 42 Degrees

Air-Valve Valve Spring Wind Up: 7/8"

1978 CHECKER

Popular Options:

Air Conditioning, Dual Air Conditioning, Auxiliary Underseat Heater, Tinted Glass, Power Rear Door Locks, Transmission Oil Cooler, Rear Window Defogger, Spotlight, AM Radio, AM/FM Radio, Two-Way Radio Antenna, Whitewall Tires, Full Wheel Discs, Two-Tone Paint, Heavy Duty Shock Absorbers, Jump Seats, Vinyl top, Heavy Duty Battery, Limited Slip Differential, HR78 X 15 Tires, 305 Cubic Inch V-8 Engine, 350 Cubic Inch V-8 Engine.

1978 Checker Historical Data:

Automatic Transmission, Power Disc Brakes, and Power Steering were Standard Equipment;

1978 Checker Model Year introduction date is not available.

Model Year Production:

307 Private Passenger Cars

5,196 Taxi Cabs

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