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?
http://modelahouse.com/cgi-bin/enumbers/numdate
Want to know about milestone engines and design changes?
http://www.plucks329s.org/studies/studies_ep/studies_ep.html
Want to know more about engine production, especially foreign “A” engines?
https://www.fordgarage.com/
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
Nut Sizes:
- 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
 
Stud Sizes:
- Regular Head Studs: 3 1/2″ Long
 - Water Neck Studs: 5 3/4″ Long
 
Bolt Sizes:
- 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)
 
Torque Specs:
- High Compression Head: 65 lbs
 - Standard Head: 55 lbs
 - Main Bearing Cap Torque 80-100 lbs
 - Flywheel Bolt Torque 65 ft/lbs
 
Specifications:
- 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.
 
Valves:
- 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:
 - Intake:
 - Opens 7 1/2° before TDC (top dead center)
 - Closes 48 1/2° after BDC (bottom dead center)
 - Exhaust:
 - Opens 51 1/2° before BDC
 - Closes 4 1/2° after TDC
 
Flywheel:
- 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.
 
Carburetor:
- 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 System:
- Exhaust Pipe: 2″ ID (Inside Diameter)
 - Tail Pipe: 1-5/8″ ID
 
Miscellaneous:
- 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″
 

