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 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:
- Intake:
- Opens 7 1/2° before TDC (top dead center)
- Closes 48 1/2° after BDC (bottom dead center)
- Intake:
- Exhaust:
- 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 System:
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- Exhaust Pipe: 2″ ID (Inside Diameter)
- Tail Pipe: 1-5/8″ ID
- To remove a stuck head from a “firing” engine you can loosen the head nuts about 1/8″ from the head and start the motor the compression will pop the head up and the motor will stall.
- 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″
Source: http://www.motormayhem.net/model-a-ford-reference-page/engine-specifications/
