Plymouth: The First Decade
1928 Plymouth Model Q Detailed Specifications
Detailed specifications, including tolerances and tune-up data are from [Chrysler 1934a] unless otherwise noted.
| Item | Reference | |
|---|---|---|
 |
|
|
| Axle, Front | I-Beam | |
King Pin Bushings | Bronze | |
Upper | 3/4" x 1-3/32" | |
Lower | 3/4" x 1-3/32" | |
Knuckle thrust | Ball - Top | |
Wheel bearings | Taper-roller | |
Maximum end play | 0.003" | |
Toe in | 0" - 1/8" | |
Caster | 0° - 2° | |
Camber | 0° - 4° | |
Pivot Angle | 7° | |
| Axle, Rear | Semi-floating | |
Gear ratio | 4.3 to 1 | |
Drive gear | Spiral bevel | |
Diameter and width | 8-5/8" x 1-3/16" | |
Gear and Pinion backlash | 0.005" to 0.010" | |
Pinion shaft end play | 0.0015" | |
Differential side gear and pinion backlash | 0.017" | |
Axle shaft diameter outer bearing | 1-3/8" | |
| Battery | ||
Ampere hour capacity | 90 | |
Cells | 3 | |
Voltage | 6 | |
Specific Gravity | ||
Charged | 1.250 | |
Discharged | 1.150 | |
| Brake, Hand | External Contracting | |
Location | Rear of transmission | |
Drum diameter | 7" | |
Lining width | 2" | |
Lining to drum clearance | 1/16" | |
| Brake, Service | Hydraulic Internal Expanding | |
Drum Diameter | 11" | |
Shoe width | 1-1/2" | |
Shoe to drum clearance: | ||
Bottom | 0.006" | |
Top | 0.012" | |
Pedal to floor board free play, maximum | 3/4" | |
| Camshaft | ||
Bearings | 3 | |
Size, diameter and length: | ||
No. 1 | 1-1/4" x 1-9/16" | |
No. 2 | 2" x 1" | |
No. 3 | 1-1/4" x 1-3/8" | |
End play | 0.003" to 0.005" | |
| Clutch | Single plate | |
Driven disc diameter | 8-7/8" | |
Release bearing | Ball | |
Release lever to bearing clearance | 5/32" | |
Disc run-out at rim (Maximum) | 0.015" | |
Spring tension | 160 lb. to 170 lb. at 1-11/16" | |
Pedal free play | 1-1/4" to 1-3/8" | |
| Connecting Rod | Drop forged I section | |
Between centers | 7-7/8" | |
Bearings | Babbitt cast in rod | |
Diameter and length | 1-7/8" x 1-1/2" | |
Clearance | 0.0015" to 0.002" | |
Side play | 0.003" to 0.005" | |
Weight variation limit | 1/4 oz. | |
Alignment limits at pin: | ||
Twist | 0.002" | |
Bend | 0.002" | |
| Cooling | Thermo-syphon | |
Capacity | 3 1/2 Gallons | |
| Crankshaft | ||
Bearings | Babbitt | |
Diameter and length | ||
No. 1 | 1-7/8" x 2 13/32" | |
No. 2 | 2-1/4" x 1-5/8" | |
No. 3 | 1-7/8" x 2-13/16" | |
Clearance | 0.001" to 0.002" | |
End play | 0.003" to 0.005" | |
Run-out center bearing maximum | 0.001" | |
| Cylinders | ||
Maximum taper before reconditioning | 0.0015" | |
Maximum out of round before reconditioning | 0.002" | |
Reconditioning working limits | 0.0005" | |
| Engine | L-head | |
Number of cylinders | 4 | |
Bore | 3-5/8" | |
Stroke | 4-1/8" | |
Piston displacement | 170.3 cu. in. | |
N.A.C.C. horsepower | 21.03 | |
Developed horsepower | 45 | |
Compression Ratio | 4.6 | |
Compression pressure | 68 PSI at cranking speed | [SK 2002 27] |
| Frame | Pressed steel | |
Length | 153-1/4" | |
Depth of channel | 5" | |
Flange width | 1-3/4" | |
Thickness | 9/64" | |
Cross members | 4 | |
| Fuel System | Vacuum | |
Tank capacity | 11 gal. | |
| Generator Maximum cold charging rate at 20 MPH | 16 amp. | |
| Horn | ||
Standard Equipment | Klaxon 12C | |
Horn Type | 900-A | |
| Ignition | Semi-automatic | |
Breaker Points | ||
Breaker point gap | 0.020" | |
Set points to open before top dead center | 0.050" piston travel | |
Spark plugs |
7/8"-18 S.A.E. | |
Gap |
0.025" | |
Original Plugs |
AC A AC Y for cast iron high compression “Red Head” |
[Buton2009] |
| Lamps | ||
Head | 1110 | [Chilton 1931 292] |
Instrument | 63 | [Chilton 1931 292] |
| Lubrication, Engine | Pressure | |
Oil capacity | 4 quarts | |
Oil pressure at 30 MPH | 35 to 40 P.S.I. | |
| Piston Pins | Clamped in rod | |
Diameter and length | 3/4" x 3" | |
Clearance in piston | 0.0005" to 0.001" Light finger push at normal room temperature | |
| Piston RIngs | ||
Number per piston | 3 | |
Width | ||
Upper - Compression | 1/8" | |
Center - wiper | 1/8" | |
Lower - oil control | 1/8" | |
Gap clearance | ||
Upper - compression | 0.010" to 0.015" | |
Center - wiper | 0.010" to 0.015" | |
Lower - oil control | 0.005" to 0.010" | |
Maximum side clearance in groove | 0.003" | |
| Pistons | Light alloy | |
Length | 4-1/8" | |
Feeler gauge clearance | ||
Head | 0.022" | |
Skirt | ||
Top | 0.003" | |
Botton | 0.001" | |
Weight variation limit | 1/4 oz. | |
| Speedometer Data | ||
Tire size | 4.75/20 | |
Axle ratio | 4.3 to 1 | |
Speedometer gear teeth in transmission | 5-15 | |
| Springs | Semi-elliptic | |
Front: | ||
Length and width | 35-1/2" x 1-3/4" | |
Leaves | 9 | |
Shackle washer clearance | 1/16" | |
Rear: | ||
Length and width | 53-1/2" x 1-3/4" | |
Leaves | ||
Coupe and Roadster | 7 | |
Touring | 8 | |
Sedans | 9 | |
Shackle washer clearance | 7/16" | |
| Steering Gear | Worm and sector | |
| Tires | 4.75/20 | |
Pressure | ||
Front | 40 lbs. | |
Rear | 35 lbs. | |
| Transmission | 3 speed | |
High and intermediate | Sliding gear | |
Type of gears | Spur | |
| Valves | ||
Inlet | Chrome nickle | |
Exhaust | Silcrome | |
Clearance diameter of opening | ||
Inlet | 1-9/16" | |
Exhaust | 1-7/16" | |
Stem diameter | 3/8" | |
Clearance in guide | ||
Inlet | 0.002" to 0.004" | |
Exhaust | 0.0035" to 0.004" | |
Seat angle | 45° | |
Lift | 9/32" | |
Tappet clearance | ||
Hot engine | ||
Inlet | 0.004" | |
Exhaust | 0.006" | |
For valve timing | ||
Inlet | 0.008" | |
Exhaust | 0.008" | |
Timing | ||
Inlet opens past top center | 5° | |
Piston travel | 0.010" | |
Inlet closes past bottom center | 45° | |
Duration of inlet | 220° | |
Exhaust opens before bottom center | 49° | |
Exhaust closes past top center | 3° | |
Piston travel | 0.004" | |
Duration of exhaust | 232° | |
Springs | ||
Length, valve closed | 1-7/8" | |
Tension, valve closed | 38 to 40 lbs. | |
Limit of compression | 1-9/16" |