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ENGINE SPECS

1951 De Soto 250 Inline Six Engine Specs

GENERAL SPECIFICATIONS

Model Designation: Six Cylinder
     De Luxe 6 - S15S
     Custom 6 - S15C

Wheel base: 125-1/2

Valve Location: In block

Bore and Stroke: 3-7/16 x 4-1/2

Piston displacement, Cubic Inches: 250.6

Compression ratio: 7.0

Maximum Brake Horsepower: 116 @ 3600 RPM

Maximum Torque Lbs.Ft. @ RPM: 208 @ 1600

Normal Oil Pressure Pounds: 50

TUNE UP SPECIFICATIONS

Spark Plug Make: Auto-Lite AR8

Spark Plug Gap, Inch: .035

Firing Order: 153624

Ignition Timing: 2 degrees BTDC Timing mark location: Vib. Damp.

Engine Idle Speed, RPM:  475

Cylinder Head Torque Lbs.Ft.: 85

Compression Pressure & Cranking Speed: 120 Min.

PISTON AND RING SPECIFICATIONS

Fitting Pistons with Scale:
Removed from above
Shim thickness to use: .002
Pounds on Pull Scale: 5 to 7

Rings: (Fit rings in tapered bores for clearance shown in tightest portion of ring travel.)
Compression: .007; Oil: .007
Clearance in groove: Compression: Top ring: .002-.004; second ring: .0015-.0035; Oil: .001-.0025

Wristpin Diameter, Inch: .8591-.8593

VALVE SPECIFICATIONS

Operating Clearance:
     Intake: .008 Hot  Exhaust: .010 Hot

Clearance for timing Intake: .014

Valve Seat Angle, degrees: 45

Valve Timing: (BTDC = before top dead center; ATDC = after top dead center)
         Intake opens: 12 degrees BTDC
         Exhaust Closes: 6 ATDC

Valve Spring Pressure Pounds at Inches Length:
     Spring: 40 @ 1-3/4

Valve Stem Clearance:
    Intake: .001-.003
    Exhaust: .002-.004

ENGINE BEARING SPECIFICATIONS

Connecting Rod Bearings:
    Journal Diameter, Inches: 2.124 - 2.125
    Bearing Clearance, Inch: .0005-.0015
    Rod End Play, Inch: .006-.011
    Rod Bolt Tension, Lbs.Ft.: 45-50

Main Bearings:
    Journal Diameter, Inches: 2.499-2.500
    Bearing clearance: .0005-.0015
    Shaft End Play: .003-.007 (Thrust taken by rear bearing)
    Main bolt tension, Lbs.Ft.: 80-85

CAPACITY DATA

Cooling System:
    Without heater: 15 quarts
    With heater: 16 quarts

Fuel Tank: 17 gallons

Engine Oil: 5 quarts

Transmission: 2-3/4 pints (with semi-automatic transmission: 3 pints)

Rear Axle: 3-1/4 pints

AUTO-LITE DISTRIBUTOR SPECIFICATIONS

Distributor part number: 1AT-4012 (distributor rotates clockwise)

Cam Angle, degrees: 39

Breaker Point opening, Inch: .020 Plus or minus .002

Condenser Capacity: .25-.28 Mfds.

Breaker Arm Spring Tension: 17-20 Oz.

Centrifugal Advance: (degrees at RPM of distributor)
   Advance starts 1 degrees @ 450
   Full Advance: 10 degrees @ 1425

Vacuum Advance Data:
   Degrees @ Inches of Mercury:
       Advance starts: 1 @ 6
       Full Advance: 9 @ 15

AUTO-LITE GENERATOR SPECIFICATIONS

Generator Number: GGW-6001J (generator rotates clockwise, 6 volts, Positive Ground)

Generator output: 45 @ 2125 RPM

Brush Spring Tension: 35-53 oz.

Field Current: 1.4-1.5 at 5 volts

AUTO-LITE REGULATOR SPECIFICATIONS

Regulator Number: VBE-6001A

Cutout Relay:
    Voltage to close points: 6.5
    Reverse current to Open Points (Amps): 4-6
    Armature Air Gap: .031

Voltage Regulator Setting: 7.3 volts

Current Regulator Setting: 45 amps

Current and voltage armature air gap, Inch: .048

AUTO-LITE STARTING MOTOR SPECIFICATIONS

Part number: MCL-6109 (starter rotates clockwise)

Bush Spring Tension, Ounces: 42-53

No Load Test: 65 amps, 5.0 volts @ 4900 RPM

Torque Test: 410 Amps, 2.0 volts, Torque, Lbs.Ft.: 8.0

WHEEL ALIGNMENT SPECIFICATIONS

Caster, Degrees
    Limits: -1 to -3
    
Desired: -2

Camber, Degrees
    Limits: -3/8 to +3/8 
    Desired:
0

Toe-In, Inches: 0 to 1/16

Toe-Out on Turns, Degrees: (If toe-out is incorrect, when other adjustments are correct, look for bent steering arms.)
    Outer wheel: 20
    Inner Wheel: 20-1/2 to 22-1/2

Kingpin Angle, Degrees: 5 to 6-1/2


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