1939 WILLYS



Model Designations:

Willys, Model 48, 4 Cylinder

Overland, Model 77, 4 Cylinder


Willys, Model 48, 4 Cylinder Body Styles


Coupe, Base Price: $495


2 Door Sedan, Base Price: $535


4 Door Sedan, Base Price: $555


Speedway Coupe, Base Price: $596


Speedway 2 Door Sedan: $616


Speedway Sedan, Base Price: $631


Special Speedway Coupe, Base Price: $610


Special Speedway 2 Door Sedan, Base Price: $631


Special Speedway Sedan, Base Price: $646


DeLuxe Coupe, Base Price: $646


DeLuxe 2 Door Sedan: Base Price: $667


DeLuxe 4 Door Sedan: Base Price: $689



Overland, Model 77, 4 Cylinder


No Body Data Available





General Specifications, Model 48


Wheelbase: 100 Inches

Engine Type: Inline 4, L-Head

Bore & Stroke: 3-1/8" X 4-3/8"

Engine Displacement: 134.2 Cu. In.

Compresssion Ratio: 5.70:1

Taxable Horsepower: 15.63

Horsepower: 48 @ 3,200 RPM

Torque: Not Available

Rear Axle Ratio: Not Available

Carburetor: Not Available .

Tire Size: 5.50 x 16 inches; Inflation Pressure, Front 28, Rear, 30


General Specifications, Model 77


Wheelbase: 100 Inches

Engine Type: Inline 4, L-Head

Bore & Stroke: 3-1/8" X 4-3/8"

Engine Displacement: 134.2 Cu. In.

Compresssion Ratio: 6.35:1

Taxable Horsepower: 15.63

Horsepower: 61 @ 3,400 RPM

Torque: Not Available

Rear Axle Ratio: Not Available

Carburetor: Not Available .

Tire Size: 5.00 x 16 inches; Inflation Pressure, Front 30, Rear, 30




Tune Up Specifications, Model 48


Spark Plug: Gap .025"

Spark Plug Type: Champion J-8 (2 Rib), J-11, or Equivalent

Point Gap: .020"

Distributor Cam Angle: 41 degrees

Ignition Timing: "IGN" Mark on Flywheel

Firing Order: 1342

Tappet Clearance, Hot: Intake .004", Exhaust .006"

Cylinder Head Torque: 60-65 Ft Lbs


Tune Up Specifications, Model 77


Spark Plug: Gap .025"

Spark Plug Type:

Point Gap: .020"

Distributor Cam Angle: 41 degrees

Ignition Timing: Early Models: "IGN" Mark on Flywheel; Late Models, 5 Degree Mark on Flywheel

Firing Order: 1342

Tappet Clearance, Hot: Intake .014", Exhaust .014"

Cylinder Head Torque: 60-65 Ft Lbs


Carburetor Specifications:



Valve Specifications, Model 48


Tappet Clearance, Running Hot: Intake .004"; Exhaust .006"

Clearance for Timing: Intake: .010"; Exhaust: .010"

Valve Timing: Intake Opens At Top Dead Center

Exhaust Closes 5 degrees After Top Dead Center

Valve Seat Angle: Intake 45 degrees; Exhaust 45 degrees,

Valve Spring Pressure: 46 Lbs @ 2-1/4 inches (New Springs)

Valve Stem Clearance: Intake .002"-.004"

Exhaust .003"-.005"



Valve Specifications, Model 77


Tappet Clearance, Running Hot: Intake .014"; Exhaust .014"

Clearance for Timing: Intake: .020"; Exhaust: .020"

Valve Timing: Intake Opens 9 Degrees Before Top Dead Center

Exhaust Closes 12 degrees After Top Dead Center

Valve Seat Angle: Intake 45 degrees; Exhaust 45 degrees,

Valve Spring Pressure: 53 Lbs @ 2-7/64 inches (New Springs)

Valve Stem Clearance: Intake .0015"-.003"

Exhaust .002"-.004"


Piston & Ring Data


Piston Removal: From Above

Piston Clearance (Minimum):

Top Land Inch .018"

Top of Skirt, Inch: .002"

Fitting Pistons with Spring Scale:

Shim Thickness: .0025 using a 3/4" wide feeler gauge

Pounds Pull on Scale: 5 to 10

Width of Ring End Gap (Minimum):

Compression Ring: .008"

Oil Ring: .008"

Clearance Between Ring & Grooves:

Compression Ring: .0005"-.001"

Oil Control Ring: .001"-.0015"


Engine Bearing Data


Camshaft End Play: Automatically controlled by spring & plunger at front

Camshaft Bearing Clearance: .002"-.0035"

Rod Journal Diameter: 1.9375"-1.9385"

Rod Bearing Clearance: .001"-.0025"

Rod End Play: .005"-.009" inches

Rod Bolt Tension: 50-55 Lbs. Ft.

Main Bearing Journal Diameter: 2.3335"-2.3340"

Main Bearing Clearance: .001" -.0025"

Crankshaft End Play: .004"-.008"

Main Bolt Tension: 60-70 Lbs. Ft.



Capacities, Model 48


Cooling System: 11 Quarts

Fuel Tank: 8 Gallons;

Engine Oil Refill: 4 Quarts;

Grade of Oil: Above +32F 20;

Above +10F 20W;

Above -10F 10W

Transmission: 1-1/4 Pint

Grade of Oil: Summer 90, Winter 90

Rear Axle: 1-1/4 Pints

Grade of Oil: Summer 90, Winter 90




Capacities, Model 77


Cooling System: 11-3/4 Quarts

Fuel Tank: 8 Gallons;

Engine Oil Refill: 4 Quarts;

Grade of Oil: Above +32F 20;

Above +10F 20W;

Above -10F 10W

Transmission: 1-1/4 Pint

Grade of Oil: Summer 90, Winter 90

Rear Axle: 1-1/4 Pints

Grade of Oil: Summer 90, Winter 90



Beginning Engine Numbers: Model 48: 89001

Model 77: 1001



Beginning Serial Numbers:



Brake Specifications, Model 48


Lining Material: Primary Shoe: Molded; Secondary Shoe, Woven.

Lining Dimensions/Wheel in Inches: 19-3/16"

Width: 1-3/4",

Thickness: 5/32"

Pedal Free Play: 1/2"




Brake Specifications, Model 77


Lining Material: Primary Shoe: Molded; Secondary Shoe, Woven.

Lining Dimensions/Wheel in Inches:

Front Wheel: 18-13/16"

Rear Wheel: 16-3/8"

Width: 1-3/4",

Thickness: 5/32"

Pedal Free Play: 1/2"



Wheel Alignment Specifications


Caster: +3 Degrees

Camber: +2 Degrees

Toe In; 3/32"

Kingpin Angle: 7-1/2 Degrees



Rear Axle Data


Ring Gear & Pinion Backlash: .004"-.008"

Drive Pinion Adjustment: Shims

Drive Pinion Bearing Adjustment: Shims

Axle Shaft End Play: .004"-.006"



Auto-Lite Distributor Specifications:


Distributor #1GS-4007B

Cam Angle: 47 Degrees

Breaker Point Opening: .020"

Condenser Capacity: .20-.25 Mfds

Breaker Arm Spring Tension: 17-20 Ounces

Centrifugal Advance Data:

Advance Starts: 2 Degrees @ 550 RPM

Full Advance: 9-1/2 Degrees @ 1,500 RPM

Vacuum Advance Data:

Advance Starts: 1 Degree @ 6-1/2" Vacuum

Full Advance: 7 Degrees @ 15" Vacuum


Distributor #1GW-4129

Cam Angle: 41 Degrees

Breaker Point Opening: .020"

Condenser Capacity: .20-.25 Mfds

Breaker Arm Spring Tension: 17-20 Ounces

Centrifugal Advance Data:

Advance Starts: 2 Degrees @ 550 RPM

Full Advance: 9-1/2 Degrees @ 1,500 RPM

Vacuum Advance Data:

Advance Starts: 2 Degrees @ 5-3/4" Vacuum

Full Advance: 10 Degrees @ 15" Vacuum



Auto-Lite Generator Specifications:


Generator #GAM-4504A

Brush Spring Tension:

Main: 18-22 Ounces

Third: 18-22 Ounces

Direction of Rotation: Clockwise

Field Current at 6 Volts: 3.89-4.31 Amperes

Low Output Test: 8 Amperes, 8 Volts @ 1,070 RPM

Maximum Output: 17.5 Amperes, 8 Volts



Generator #GAM-4504B

Brush Spring Tension:

Main: 18-22 Ounces

Third: 18-22 Ounces

Direction of Rotation: Clockwise

Field Current at 6 Volts: 3.89-4.31 Amperes

Low Output Test: 8 Amperes, 8 Volts @ 1,070 RPM

Maximum Output: 17.5 Amperes, 8 Volts



Generator #GBM-4612A

Brush Spring Tension:

Main: 50-60 Ounces

Third: 50-60 Ounces

Direction of Rotation: Clockwise

Field Current at 6 Volts: 3.80-4.20 Amperes

Low Output Test: 8 Amperes, 7.6 Volts @ 1,250 RPM

Maximum Output: 21 Amperes, 8 Volts



Generator #GCJ-4811A

Brush Spring Tension:

Main: 53 Ounces (Maximum)

Third: 53 Ounces (Maximum)

Direction of Rotation: Clockwise

Field Current at 6 Volts: 1.90-2.10 Amperes

Low Output Test: 8 Amperes, 8 Volts @ 1,135 RPM

Maximum Output: 26 Amperes, 8 Volts



Auto-Lite Regulator Specifications:


Regulator Type: Regulated by Third Brush

Regulator Number: CB-4025

Armature Air Gap: .010" to .030"

Point Gap: .015" to .045"

Voltage to Close Points: 6.5-7.25

Amperage to Open Relay Points: 0.5-2.5

Maximum Operating Amperage: 15 Amperes


Regulator Type: Voltage

Regulator Number: VRD-4004A

Ground Polarity: Negative

Voltage to Close Points: 6.4-7.0

Amperage to Open Relay Points: 0.5-3.0

Maximum Operating Amperage: 15 Amperes

Maximum Operating Voltage:

Before #8R-000001: 7.65 Volts

#8R-000001 & Later: 7.45 Volts





Auto-Lite Starting Motor Specifications:


Unit #: MZ-4049

Brush Spring Tension: 42-53 Ounces

No Load Test:

70 Amperes; 5.5 Volts; @ 4,300 RPM

Lock Test:

560 Amperes; 4.0 Volts; Torque 11.8 Ft Lbs


Unit #: MZ-4064

Brush Spring Tension: 42-53 Ounces

No Load Test:

70 Amperes; 5.5 Volts; @ 4,300 RPM

Lock Test:

560 Amperes; 4.0 Volts; Torque 11.8 Ft Lbs



Tillitson Carburetor Adjustments:


Idle Screw: 1 Turn Open

Main Adjustment: -3/8 Turns Open

Fuel Level: 3/4" below upper rim of float bowl.



Fuel Pump Data:


Pump Model: AF

Maximum Pressure: 3 PSI





Dash Gauge Manufacturers:


Gasoline: King-Seeley

Temperature: King-Seeley

Oil Pressure: King-Seeley

Ammeter: King-Seeley








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