What Do Ford Model A Engine Numbers Mean + Engine Specifications

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…

• Ford Model A Engine Specifications

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″