Oil Pump Specifications
Type: Pump, splash, gravity feed
Crankshaft Bearings: Gravity feed
Connecting Rods: Splash
Camshaft Bearings: Gravity feed
Oil Pump Type: Gear
Oil Pump Capacity: 9 pints, minimum at 1300 rpm
Oil Pump Pressure: 80-100 pounds
Oil Pump Shaft: 1/2" diameter (in 5/8" bore), except 1928 with 9/16" bore & undercut shaft (Model B used 5/8" bore with undercut shaft)
Oil Pump Gear Teeth to Housing Clearance: .001" to .002"
Housing Cover to Face of Gears Clearance: .001" to .002"
Drive Gear to Camshaft Gear Clearance: .003" to .005"
Transmission Specifications
Gear & Shaft Material: Chromium alloy steel
Gear Ratios:
High-1:1 (100%)
2nd-6.89:1 (53.8%)
Low-8.75:1 (32.04%)
Reverse-26.7%
Bearings:
Main shaft front (ball) 1208;
Main shaft rear (ball) 1306
Transmission Case Length: 6.560" to 6.565"
Case Front Bearing Hole: 3.1497" to 3.1507" diameter
Case Rear Bearing Hole: 2.835" to 2.836" diameter
Clutch Specifications
Material: Molded asbestos composition
Pressure Plate Weight: 15 pounds
Clutch Disc Weight: 2-1/2 pounds
Pivot Pedal Pressure: 30 pounds
Clutch Facings: 9" diameter, 9/64" thick
Inside Diameter: 5-3/4"
Total Acting Surface Area: 75 square inches
Clutch Pedal Clearance: 3/4" for multiple disc, 1" for single
Clutch Release Bearing Hub: 2.065" diameter
Clutch Throw Out Bearing: B7580 or B7580T
Clutch Pressure: 1100 pounds
Radiator Specifications
1928 Manufacturer Ford
1929 Manufacturer Flintcock, Long, McCord
1930-31 Manufacturer Ford
Standard Radiators 1928-29
Tubes Flat 1/2" seamless
Number of Tubes 101 in 3 rows, staggered at 9/16" centers
Number of Fins 5 fins/inch-98 fins
Core Size 19-3/4" x 19-1/8" x 2-3/16" centers
1928-29 Heavy Duty 8 fins/inch-158 fins
Standard Radiators 1930-31
Tubes Flat 1/2" seamless
Number of Tubes 95 in 3 rows, staggered at 9/16" centers
Number of Fins 5 fins/inch-100 fins
Core Size 20-1/8" x 18" x 2-3/16" centers
1930-31 Heavy Duty 8 fins/inch-167 fins
Zenith Carburetor Specifications
Throat Size: 1"
Float Level: 5/8" below upper body machined surface. Model B, 33/64" below upper body machined surface.
Main Jet: .037" ID (#63 drill bit)
Cap Jet: .037" ID
Compensator Jet: .035" ID (#65 drill bit)
Idling Jet: .021" ID (#75 drill bit)
How to Tell if You Have a Zenith or a Tillotson Carburetor?
It’s easy. The original Zenith carburetors had round-shaped cast iron bodies, while Tillotson carburetors were made of an aluminum alloy, with more of a “boxy” shape. Usually, Zenith carburetors are found painted black, while Tillotsons are normally unpainted aluminum color.
Water Pump Specifications
Water Pump Shaft: 5/8" diameter
Water Pump Shaft End Play: .006" to .010"
Radiator Hose:
Upper: 2" diameter, 6-1/4" long (28-29) 8" long (30-31).
Lower: (2 pieces) 1-3/4" diameter,
2-3/4" long.
Fan Blade & Belt Specifications
Fan Belt Width: 5/8"
Fan Belt Length: 42-7/8"
Fan Cooling Surface: 374 square inches
Fan Speed: 1-1/2 times engine rpm. Fan delivers about 855 cfm at 1,000 rpm, about 24 mph
4 Blade Fan: At 1,000 rpm, 62% increase in air flow,
82% increase in HP absorbed; at 2,000
rpm, 55% increase in air flow, 47%
increase in HP absorbed.
Gas Tank Specifications
Steel Thickness: .049" to .051" (terne plated)
Capacity: 28-29: 10 gallons 30-31: 11 gallons
Generator Specifications
Type: Two pole
Voltage Regulation: Fixed control
Brushes: 3 (1 adjustable)
Armature Bearings:
29-Mid ’30: Ball front & rear
After Mid 30: Ball front, bushing rear
Armature Speed: 1-1/2 of engine speed
Armature Length: 28-April ’30: 7-9/16" - uses 1-5/32" wide pulley
after April 30: 7-21/32" - uses 7/8" wide pulley
Max. Normal Charging Rate: 12 amps @ armature 1600 rpm (25mph)
Cutout Closes: Approximately 9 mph
Cutout Opens: Approximately 8 mph
Contact Gap: .015" to .020"
Core Gap: .010" (contacts closed)
Brush Spring Tension: 25 to 40 ounces each
Field Coils: 100 turns of #17 copper wire
Armature: 14 coils with 6 turns of #17 copper wire
Commutator: 28 copper segments
Field Current Draw: 6.3 amps at 7 volts, generator
(motoring draws 5.75 amps at 7 volts)
Maximum Current: 18 to 22 amps at 6 volts
Motoring Freely: 5 amps at 6 volts
Field Test: 5.2 amps at 6 volts
The very earliest Model A Fords were equipped with “Powerhouse” generators (shown below), which had a pancake shape & a body covered with sheet metal. Soon Ford replaced them with the more familiar generator that is shown below. These generators, when working properly, are simple, durable & reliable.
Photo Captions:
1. Cut-Out
2. Cover band
3. Pulley
4. Rear End Plate
Battery Specifications
Terminal Grounded Positive
Voltage 6 volt
Capacity 80 amp hours, starting capacity 98 amps
Number of Cells 3
Number of Plates 13 per cell
Charging Rate 10 to 12 amps
Starter Motor Specifications
Type of Drive: Bendix (except early 1928)
Terminal Grounded: Positive
Rotation: Counterclockwise (viewed from commutator or bushing end)
Armature: 21 segments
Brush spring: 35 to 40 ounces
Distributor Assembly Specifications
Rotor Revolution Direction: Counterclockwise
Point Gap: .018" to .022"
Point Spring Tension: 16 to 18 oz.
Condenser Capacity: .20 to .25 mfd
Yellow Wire Ignition Circuit: 12 gauge
All Other Wiring: (except high tension circuit) 16 gauge
Camshaft to Bearing Clearance: .001" to .002"
Spark Control Manual Advance: 20° (28° camshaft travel)
Rotor End Cap to Distributor Terminal: .020"
Ignition Circuit: .62 amps at 6.2 volts (engine at 1500 rpm)
4 amps at 6.2 volts (engine stopped)
Set point gap at .018"-.022" (.022" for new points). The rubbing block on the points will wear down .003"-.005" after approximately 400-1,000 miles. After this point, wear might only be .001" over the next 10,000 miles. Therefore, be sure to reset the point opening to .022" by the end of the first 1,000 miles.
Spark Plug Specifications
Spark Plugs: Champion 3X, 7/8" x 18 thread
Spark Plug Gap:
.035" (A6050A cylinder head),
.030" (B6050 cylinder head),
.025" (A6050B cylinder head)
Interior Lights Specifications
Instrument Panel: 3 candle power, single contact, B13466
Dome: 3 candle power, single contact, B13466
Commercial Dome: 21 candle power, single contact, B13465
Cylinder Block Specifications
Length: 19-5/16"
Width: 7-13/16"
Height: 11-1/2"
Bore: 3.875" to 3.876"
Bottom of Block to Camshaft Centerline: 2.876" to 2.878"
Top of Block to Camshaft Bore Centerline: 8.624" to 8.627"
Valve Lifter & Guide Bore: .594" to .5945" diameter
Distributor Drive Gear Bore: .9365" to .9375" diameter
Cylinder Outside Diameter: 4-3/8" outside diameter
Flatness of Top of Block: .003" to .005"
Cylinder Bore Perpendicular
to the Top of the Block: .001" to .002"
Windshield Wiper Information
From the start of production, the Model A was equipped with windshield wipers. Early wipers were either manual (commercial & open car) or electric (closed car). All ’28 electric wipers were made by the Owen-Dyneto Company, who used zinc die-castings (also known as pot metal) for the base, cover & levers. This was a very brittle metal that broke & warped over the years, leaving very few intact wipers.
Beginning in February ’29, Ford began using electric wipers from Heinz Electric Company & in March ’29 from E.A. Laboratories, Inc. These new wipers were made from pressed steel & were much more durable.
General Sheet Metal Information
When faced with rusted or missing Model A sheet metal, yesterday’s restorer had to rely on used metal panels & body parts from a dry climate, or hand-made panels hammered out by highly talented metalsmiths.
But today, MAC's Antique Auto Parts is proud to offer a tremendous selection of precision-crafted sheet metal panels & components for many different Model A body styles. Like the original panels, MAC's sheet metal parts are die stamped from heavy gauge steel, with correct flanges, contours & seams as original. You’ll like working with new solid steel instead of thin & rust-weakened panels full of body filler.
As with any new body part, these panels might require some fitting & minor metal work & must be welded by a competent body person. Return that new-steel “solid” feeling to your Model A with brand new steel sheet metal parts & panels from MAC's!
MAC's DISCLAIMER:
The content MAC's presents on its "Vehicle Identification & Specification" pages & in its catalogs is for information use only and is intended to be used as a guide. While MAC's makes every effort to ensure accurate content, occasionally errors may occur. MAC's does not take responsibility & will not be held liable for any automotive parts purchases, repairs or restoration decisions made as a result of information presented here or anywhere in its catalogs.