1931 Plymouth Model PA Detailed Specifications

Detailed specifications, including tolerances and tune-up data are from [Chrysler 1934a] unless otherwise noted.

1. Axle, FrontI-Beam
   1. King Pin BushingsBronze
      1. Upper3/4" x 1-3/32"
      2. Lower3/4" x 1-15/32"
   2. Knuckle thrustBall - Top
   3. Wheel bearingsTaper-roller
      1. Maximum end play0.003"
   4. Toe in1/32" - 3/32"
   5. Caster1°
   6. Camber1-1/2°
   7. Pivot Angle7°
2. Axle, RearSemi-floating
   1. Gear ratio4.33 to 1
   2. Drive gearSpiral bevel
      1. Diameter and width8-3/4" x 1-3/16"
   3. Gear and Pinion backlash0.005" to 0.010"
   4. Pinion shaft end play0.0015" to 0.0025"
   5. Differential side gear and pinion backlash0.017"
   6. Axle shaft diameter outer bearing1-3/8"
3. Battery
   1. Ampere hour capacity84
   2. Cells3
   3. Plates13
   4. Voltage6
   5. Specific Gravity
      1. Charged1.250
      2. Discharged1.150
4. Brake, HandExternal Contracting
   1. LocationRear of transmission
   2. Drum diameter6"
   3. Lining width2"
   4. Lining to drum clearance1/16"
5. Brake, ServiceHydraulic Internal Expanding
   1. Drum Diameter11"
   2. Shoe width1-1/2"
   3. Shoe to drum clearance:
      1. Bottom0.006"
      2. Top0.012"
   4. Pedal to floor board free play, maximum3/4"
6. Camshaft
   1. Bearings3
   2. Size, diameter and length:
      1. No. 11-1/4" x 1-3/4"
      2. No. 22" x 1-1/16"
      3. No. 31-1/4" x 1-17/32"
   3. End play0.003" to 0.005"
7. ClutchSingle plate
   1. Driven disc diameter8-7/8"
   2. Release bearingBall
   3. Release lever to bearing clearance1/8"
   4. Disc run-out at rim (Maximum)0.015"
   5. Spring tension165 lb. to 175 lb. at 1-11/16"
8. Connecting RodDrop forged I section
   1. Between centers8-9/16"
   2. BearingsBabbitt cast in rod
      1. Diameter and length2" x 1-3/8"
      2. Clearance0.00075" to 0.0025"
      3. Side play0.003" to 0.009"
   3. Weight variation limit1/4 oz.
   4. Alignment limits at pin:
      1. Twist0.002"
      2. Bend0.002"
9. CoolingPump
   1. Capacity3 5/8 Gallons
10. Crankshaft
    1. BearingsBabbitt
       1. Diameter and length
          1. No. 12-1/4" x 2 1/8"
          2. No. 22-1/4" x 1-5/8"
          3. No. 32-1/4" x 2-3/8"
       2. Clearance0.001" to 0.002"
       3. End play0.003" to 0.006"
    2. Run-out center bearing maximum0.001"
11. Cylinders
    1. Maximum taper before reconditioning0.0015"
    2. Maximum out of round before reconditioning0.002"
    3. Reconditioning working limits0.0005"
12. EngineL-head
    1. Number of cylinders4
    2. Bore3-5/8"
    3. Stroke4-3/4"
    4. Piston displacement196.1 cu. in.
    5. N.A.C.C. horsepower21.03
    6. Developed horsepower56
    7. Compression pressure74 PSI at cranking speed [SK 2002 27]
13. FramePressed steel
    1. Length155-17/32"
    2. Depth of channel5-1/2"
    3. Flange width2"
    4. Thickness9/64"
    5. Cross members4
14. Fuel SystemPump
    1. Tank capacity11 gal.
15. Generator
    1. Maximum cold charging rate at 20 MPH16 amp.
16. Horn
    1. Standard EquipmentKlaxon 16
       1. Horn Type1306-A
       2. Amps @6v5 to 7.5 [SK 1984 10]
       3. Air Gap (High Note)0.015 - 0.017" [SK 1984 10]
       4. Air Gap (Low Note)0.020 - 0.022" [SK 1984 10]
17. IgnitionFull Automatic
    1. Breaker Points
       1. Breaker point gap0.020"
       2. Cam Angle (Degrees)52° [Sk 2002 27]
       3. Set points to open before top dead center0.046" piston travel
    2. Spark plugs18 mm. metric
       1. Original PlugsAC G12 [SK 2002 27]
       2. Gap0.025"
18. Lamps
    1. Head1110 [Chilton 1931 292]
    2. Instrument63 [Chilton 1931 292]
19. Lubrication, EnginePressure
    1. Oil capacity6 quarts
    2. Oil pressure at 30 MPH30 to 40 P.S.I.
20. Piston PinsClamped in rod
    1. Diameter and length3/4" x 3"
    2. Clearance in piston0.00025" to 0.00075"
       Light thumb push at normal room temperature
21. Piston RIngs
    1. Number per piston4
    2. Width
       1. Upper - Compression1/8"
       2. Center - wiper1/8"
       3. Lower - oil control5/32"
    3. Gap clearance
       1. Upper - compression0.007" to 0.015"
       2. Center - wiper0.007" to 0.015"
       3. Lower - oil control0.004" to 0.009"
    4. Maximum side clearance in groove0.003"
22. PistonsLight alloy
    1. Length4-1/8"
    2. Feeler gauge clearance
       1. Head0.022"
       2. Skirt
          1. Top0.003"
          2. Botton0.001" to 0.0015"
    3. Weight variation limit1/4 oz.
23. Speedometer Data
    1. Tire size4.75/19
    2. Axle ratio4.33 to 1
    3. Speedometer gear teeth in transmission5-15
24. SpringsSemi-elliptic
    1. Front:
       1. Length and width35-1/2" x 1-3/4"
       2. Leaves7
    2. Rear:
       1. Length and width53-3/8" x 1-3/4"
       2. Leaves7
25. Steering Gear
    1. Steering wheel17" three spoke
    2. TypeWorm and sector
26. Tires4.75/19
    1. Pressure
       1. Front40 lbs.
       2. Rear35 lbs.
27. Transmission3 speed
    1. High and intermediateConstant mesh with sliding clutch
       1. Type of gearsSpur and helical
    2. Second speed gear maximum end play0.002"
    3. Free wheel drive shaft bearing end play0.002"
28. Valves
    1. InletChrome nickle
    2. ExhaustSilcrome
    3. Clearance diameter of opening
       1. Inlet1-11/16"
       2. Exhaust1-7/16"
    4. Stem diameter3/8"
       1. Clearance in guide
          1. Inlet0.002" to 0.004"
          2. Exhaust0.003" to 0.005"
    5. Seat angle45°
    6. Lift5/16"
    7. Tappet clearance
       1. Hot engine
          1. Inlet0.005"
          2. Exhaust0.007"
       2. For valve timing
          1. Inlet0.008"
          2. Exhaust0.009"
    8. Timing
       1. Inlet opens past top center6°
       2. Inlet closes past bottom center46°
       3. Duration of inlet220°
       4. Exhaust opens before bottom center42°
       5. Exhaust closes past top center8°
       6. Duration of exhaust230°
    9. Springs
       1. Length, valve closed1-7/8"
       2. Tension, valve closed40 to 44 lbs.
       3. Limit of compression1-9/16"