Stock Model A & B Camshaft Grind Specifications
By Marco Tahtaras

The following is for original NEW Model A and B cams only Regrinds will have substantially different characteristics regardless of what they are called.

The Model A cam was ground as follows: Lobe Lift = 302″
Valve lift = 289″ @ 013″ clearance
duration @ valve seat to seat = 236 crankshaft degrees @ 015″ clearance
Lobe centers = 112 crankshaft degrees
Intake center = 110 5° after TDC

Intake opens = 7 5° before TDC
Intake closes = 48 5° after BDC
Exhaust opens = 51 5° before BDC
Exhaust closes = 4 5° after TDC

The Model B cam was ground as follows: Intake lobe lift = 334″
Intake Valve lift = 319″ @ 015″ clearance
Exhaust lobe lift = 341″
Exhaust Valve lift = 319″ @ 022″ clearance
duration @ valve seat to seat = 244 crankshaft degrees @ above clearances
Lobe centers = 114 crankshaft degrees
Intake center = 114° after TDC

Intake opens= 8° before TDC
Intake closes= 56° after BDC
Exhaust opens= 56° before BDC
Exhaust closes= 8° after TDC


Rear Frame Stampings

Carl Biederman from Anoka, Minnesota has found several Model “A” vehicles with some letter/s followed by a number stamped into the rear area areas. The locations of the stampings have been noted on the rear end axle housing, top of the rear frame cross member and the right rear corner of the rear frame cross member (see picture below from Eldon Frisk).

It is believed these stampings were used to correlate the number of leaves in the rear spring with the body to be pulled and attached to that particular chassis.

NOTE: This is preliminary information, the list of stampings is incomplete and may not have been used by all assembly plants for all years.

Following are the stampings noted to date with their interpretations:

Body Style
Rear Spring Leaves
Seven leaves
Eight leaves
Open Cab Pickup
Ten leaves
Ten leaves
Town Sedan
Ten leaves
Ten leaves
storiesFrame stamp web
Additional front and rear spring information for both Model A Passenger cars and Trucks may be found in the Restoration Guidelines and Judging Standards Area 4 – Undercarriage. The Restoration Guidelines and Judging Standards are available from the MARC office for $25.

Specifications and License Data

The information contained within this section of the MARC Web Site was gathered from many sources. The information in general reflects original Ford data and was the best information available at the time of collection. It is not intended to be all-inclusive nor does it reflect all design changes. The intent is to provide some general information regarding various specifications for the “New Ford”. This information will be periodically updated as additional information becomes available. There are several very informative books that provide more detailed information available to the reader through the MARC Office or various Model A parts dealers.
Engine Type
4 cylinder, L head
Engine Material
Gray Cast iron
Engine Cylinders
4, cast engine block, 1/8” offset
Engine Firing Order
1, 2, 4, 3
Engine Displacement
200.5 cu. inches
Diameter of Cylinder Bore
Diameter of Pistons
Crankshaft Material
Ford Carbon Manganese Steel
Crank Gear
Steel, 25 spiral-cut teeth
Diameter of Crankshaft
Main Bearings
Diameter of Crankshaft
Pin Bearings
SAE rating, 24.03
Brake, 40 @ 2200 RPM
128 ft-lbs @ 1000 RPM
Compression ratio
4.22 to 1
76 psig
Cast iron
Flywheel Ring Gear
Steel, 14.2 inch outside dia, 112 teeth
Camshaft Bearings
early 5 bearings (later 3), 1.560
Camshaft Lift
Camshaft Gear
Phenolic resin material, 50 spiral-cut teeth
Valve lift
Valve Clearance
0.010 to 0.013
Breaker point gap
0.018 to 0.022
Spark plug gap
Oil System
Engine lubricated by gear pump, splash and gravity feed. Capacity 5 quarts.
Selective sliding rear type, three speeds forward and reverse. Capacity 1 pint.
Early to mid 28, Multiple disc
Later 1928 to end – Single Plate
Four wheel internal expanding service brakes operated by the foot petal. Also an emergency or parking brake on both rear wheels operated by the emergency brake lever. Emergency brakes are entirely separate and distinct from the four- wheel service brakes. Total braking surface 225 1/2 sq inches.
Cooling System
Pump and thermo-syphon. Capacity 3 gallons.
Water pump shaft end play
0.006 to 0.010
Zenith design, cast iron; manual adjustment and choke control on dash panel
Gasoline tank
10 gallons
Rear Axle
Three-quarter floating type. Torque tube drive. Spiral bevel drive pinion and gear. Capacity 1.5 pints
Wheel Base
103.5 inches
Turning radius
17 ft, circle 34 ft.
56 inches
Road Clearance
9.5 inches
Average Summer Charging Rate
– 6 to 8 amps @ 1500 RPM
Average Winter Charging Rate
– 10 to 12 amps @ 1500 RPM