People often ask in the early Ford forums: “What does the number on my Model A engine mean?”
Is it a serial number? Is there a record of what body style and color of the car the engine was originally installed in? Can it tell me the date my Model A was built?
This video tries to briefly explain the history of the Model A engine numbers and what information you can find out about your car from it…
Please check out these informative web pages to learn more about the Model A Engine and about your car.
Want to know the exact date a Model A engine was stamped?
Want to know about milestone engines and design changes?
Want to know more about engine production, especially foreign “A” engines?
How The Model A Ford Engine Was Built; The Engine Assembly Line
Every Model A engine destined for one of Ford’s 30+ US assembly plants was cast and assembled at the Rouge Plant in Dearborn, MI.
Using 22 different archived videos spliced together, this video depicts the Model A engine being produced from sand molds to being dropped in a chassis.
Watch for the main bearing babbitts being poured, the flywheel being balanced, and the manifolds being assembled…
Ford Model A Engine Specifications
- Front Motor Mount Castle Nut: 7/16″-20
- Engine Head Nuts (grade 8): 7/16″-20
- Connecting Rod Castle Nut: 7/16″-20
- Ratchet Nut (attaches bottom pulley to the crankshaft): 5/8″-18
- Main Bearing Bolt Castle Nut: 1/2″-20
- Regular Head Studs: 3 1/2″ Long
- Water Neck Studs: 5 3/4″ Long
- Flywheel to Crankshaft Bolts: Four 7/16-20 by 13/16″ Long
- Flywheel Housing to Block: Four 7/16″-14 by 1 1/16″ Long and two 7/16-14 by 1 11/16″ Long
- Timing Cover Bolts: 3/8″-16 by 1 1/8″ Long
- Side Timing Gear Bolts: One 7/16″-14 by 2 3/16″ Long and one 7/16″-14 by 1 3/8″ Long (lock washers can be used)
- High Compression Head: 65 lbs
- Standard Head: 55 lbs
- Main Bearing Cap Torque 80-100 lbs
- Flywheel Bolt Torque 65 ft/lbs
- The stock compression ratio was about 4.22:1
- Piston displacement 200.5 cu. Inches
- Bore 3.875″
- Rated H.P. 24.03 SAE
- Brake H.P. 40
- Firing Order 1-2-4-3
- Stroke 4.250″
- Gas Tank
- 28/29– 10 GAL.
- 30/31– 11 GAL.
- Valve lift .287″
- Seat Angle: 45°
- Stem Diameter: .311″
- Port Diameter: 1 3/8″
- Valve Opening Diameter: 1 3/8″
- Valve Guide Clearance:
- Exhaust: .002″
- Intake: .001-.0015
- Valve Spring Length:
- Free: 2 15/16″
- Compressed Length: 2 1/4″
- Valve Spring Force (compressed): 57-64 lbs.
- Valve Timing:
- Opens 7 1/2° before TDC (top dead center)
- Closes 48 1/2° after BDC (bottom dead center)
- Opens 51 1/2° before BDC
- Closes 4 1/2° after TDC
- Weight: 63 lbs., 4 oz.
- Balance: Within .15 In/oz.
- Clutch Mounting Surface: True with crankshaft within .005″ TIR.
- Clutch Mounting Shoulder Diameter: Concentric with crank flange diameter within .005″ TIR.
- Throat Size: 1″
- Float Level: 1″ from float to machined surface.
- Main Jet: #63 drill bit
- Cap Jet: #63 drill bit
- Idle Jet: # 75 drill bit
- Exhaust Pipe: 2″ ID (Inside Diameter)
- Tail Pipe: 1-5/8″ ID
- Crankshaft weight 28 lbs.
- Engine Oil Capacity:
- From Empty: 5 Quarts
- Oil Change: 4 1/2 Quarts
- Spark Plugs: Champion 3X, 7/8″-18
- Spark Gap: .035″