Specifications & More

Torque specs

Axel Housing to Differential ……………… 35 ft lbs

Camshaft nut ……………………………….  100 ft lbs

Crank pulley ………………………………….  80 ft lbs

Exhaust / intake Manifold ………………..  45 ft lbs

Head nuts  ……………………………………  55 ft lbs

Fly wheel ……………………………………..   55 ft lbs

Flywheel housing – cylinder block bolts .. 55 ft lbs ( use safety wire )

Main Bearings ……………………………   70-80 ft lbs

Oil Pan …………………………………………..  20 in lbs   (snug) don’t over tighten

Pressure plate …………………………….  20-25 ft lbs

Rear axle nut …………………………………   100 ft lbs

Rod Bearings ……………………………………  35 ft lbs

Spark plugs …………………………………….    25 ft lbs

Timing Cover ……………………………………   25 ft lbs

Torque tube to Differential …………………   35 ft lbs

Valve Cover ………………………………………  20 ft lbs

Water Inlet ……………………………………….   40 ft lbs

Wheel lug nuts   64 ft lbs

CAPACITIES

Cooling System: 3 gallons
Gasoline tank: 1928-29, 10 gallons / 1930-31, 11 gallons
Engine oil pan: 5 quarts
Transmission: 1-1/2 pints
Steering gear: 7-3/4 oz
Differential: 2-1/4 pints

ENGINE

Rated horsepower: 24.03 SAE
Brake Horsepower: 40 HP @ 2200 rpm (Model AF 28 @ 2000 rpm)
Firing order: 1-2-4-3
Compression ratio: 4.22 to 1
Compression pressure: A-6050A head, 76 PSI; A-6050B head, 110 PSI; B-6050 head, 90 PSI
Piston displacement: 200.5 cu. inch
Bore: 3.876″ (Model AF: 3.050″)
Stroke: 4.250
Torque: 128 ft/lbs. at 1000 rpm
Cylinder offset from crankshaft centerline: 1/8″
Crankshaft to camshaft centerline: 4.155″

CYLINDER BLOCK

Length: 19-5/16″
Width: 7-13/16″
Height: 11-1/2″
Bore: 3.875 to 3.876″
Bottom of block to camshaft bore centerline: 2.876 to 2.878″
Top of block to camshaft bore centerline: 8.624 to 8.627″
Valve lifter and guide bore: .594 to .5945″ diameter
Distributor drive gear bore: .9356 to .9375″ diameter
Cylinder outside diameter: 4-3/8″ (wall thickness 1/4″)
Flatness of the top of block: .003 to .005″
Cylinder bore perpendicular to top of block: .001 to .002″

CRANKSHAFT

Material: Special Ford carbon manganese steel
Weight: 28 lbs.
Length: 26 inches
Diameter: 1.624″ main bearings, 1.499″ crank pins
Length of main bearings: Front and center, 2″; rear, 3″
Length of crank pins: 1-5/8″
Crank pin taper and roundness: ,0005 to .001″
Total main bearings surface: 11-1/2 sq. inches
Rear flange thickness: 3/8″
Crankshaft gear: 25 spiral teeth
End clearance: .004 to .007″
Main bearing clearance: .001″
Crankshaft straightness: .0005 to .001″
Main bearing cap torque: 55-65 ft. lbs.
Distance from top surface cross-member to crankshaft centerline: 2-33/64″

CONNECTING RODS

Material: Steel Forging
Weight: 1 lb., 6 oz.
Balance weight: 552 grams +/- 1 gram, crank end; 198 grams +/- 1 gram, pin end
Length: 7-1/2″ center to center
Crankshaft bearing: 1-1/2 diameter, 1-5/8″ wide
Piston pin bearing: 1″ diameter, 1-5/8″ wide
Bearing side clearance: .008 t0 .012″
Pin side clearance: .040 to .053″ between pin bosses
Piston pin clearance: .0005′”
Crank shaft clearance: .001″
Bearing cap bolt torque: 40-50 ft. lbs.
Connecting rod assembled with oil clippers toward camshaft.

PISTONS

Displacement: 200.5 cu. inches
Material: aluminum
Weight: 1 lb. 1-7/8 oz. (476.8 grams)
Variance in weight of pistons: +/- 2 grams
Weight with rings installed: 1 lb. 4-1/2 oz. (581.2 grams)
Weight with rings and pin: 1 lb.  8-3/4 oz. (701.7 grams)
Diameter: 3.8745″ (Bore: 3.875)
Length: 3-29/32″‘
Piston skirt: .001″ smaller at the top than the bottom of skirt
Piston pin hole: .9996 to .9998′” diameter
Piston pin diameter: 1.0001 to 1.0004″
Pin length: 3.536 10 3.546”
Compression Height (t0p of piston to pin centerline): 1-29/32″
Variation in piston compression height: .003 to .005″‘
Piston pin bushing: I.D.  .991″, O.D. 1.0675″, Length 1.593″
Pin fit in rod bushing: .0003″ max.
Pin fit in piston: .0002 to .0005″ shrink fir (not normally used today)
Pin bore parallel to head to piston: +/- .001″
Piston fit in cylinder: .002″ max.
Ring diameter: same as piston, 3.875″ stock
Ring groove: depth, 7/32″‘; grove width-upper two. 1/8″; lower. 5/32″
Ring taper: .001″ narrower at top than the bottom
Ring clearance in groove: .001 to .002″
Ring end gap: top, .012 to .015″; middle, .010 to .012″: lower, .008 to .010″

CAMSHAFT

shaft diameter: 7/8″‘
Bearing diameter: 1.560″
Block bore diameter: 1.561″
Bearing clearance (max.): .003″
Bearing length: Front 1-3/4″; center, 2″; rear 1″; 4th (1928), 7/8″
Lift of cam: .303″ (Model B: .339″ exhaust; .334″ intake)
Duration: 236°
Lobe center angle: 113-1/2″
End play spring tension: approximately 35 lbs.
Timing gear mounting flange: 2-5/16′” diameter 5/16″ thick
Camshaft material: Special Ford carbon manganese steel
Camshaft gear: made from resinated laminations of textile fabric
No. of gear teeth: 50
Camshaft gear type: spiral teeth
Gear backlash: .003 to .oo5″
Gear rotation speed: 1/2 of crankshaft
Camshaft straightness: .0005 to .001″
Variation in eccentricity of pitch diameter of gear teeth: .0015″
Variation in maintaining center distance of mating gear: +/- .001″
Gear tolerance in regular spacing of teeth: 0.0″

VALVES

Lift .287″ with .015″ clearance
Scat angle: 45°
Seat Width: 3/32″
Stem diameter: .311″ Valve length: 5.677″
Head diameter: 1.537″
Valve opening diameter: 1-3/8″
Port diameter: 1-3/8″
Clearance. exhaust valves in guides: .002″
Clearance. intake valves in guides: .001 to .0015″
Valve lifter clearance: .010 to .013″
Lifter diameter clearance: .0015″
Valve guides: I.D.-.3135″; O.D.-.5938″; length-2.125″ (early 2.375″)
Valve spring: O.D.-1.022″; free length-2-15/16″; Compressed lcngth-2.250″ (57-64 lbs.); tension (closed) -34 to 38 lbs.
Valve lifter: A-6500A (used with “A” camshaft), length – 2.486″  head diameter – 1.117″; B-6500 (used with “B” camshaft), length 2.158″ head diameter – 1.187″
Valve timing:
Model A:
Intake opens 7-1/2° before TDC (Top Dead Center)
Intake closes 48-1/2° after BDC (Bottom Dead Center)
Exhaust opens 51-1/2° before BDC
Exhaust closes 4-1/2° after TDC
Model B:
Intake opens 8° before TDC
Intake closes 56° after BDC
Exhaust opens 56° before BDC
Exhaust closes 8° after TDC

HEAD

1928 head: 4.3 to 1 compression ratio, 47.3 HP. 242cc displacement: Compression in individual cylinders: 80, 85, 83, 82 PSI
1930 Head: 4.1 compression ratio, 44.3 HP, 258cc displacement: Compression in individual cylinders: 77, 79, 82, 79 PSI
Nominal listed compression: A-6050A, 75 lbs.; A-6050B, 110 lbs.; B-6050, 90 lbs.
Head nut torque: 55 ft./lbs.

SPARK PLUGS

(also see Ignition)
type: Champion 3X
Thread: 7/8-18

IGNITION

Distributor rotor revolves: counter-clockwise
Point gap: .018 to .020”
Point Spring tension: 16 to 18 oz.
Condenser capacity: .20 10 .25 MFD
Spark plugs: Champion 3X, 7/8 x 18 thread
Spark plug gap: .035″ (6050 A head), .030″
(B-6050 head), .025” (A-6050B head)
Yellow wire ignition circuit, 12 gage. All other wiring except high tension circuit is 16 gage.
Cam shaft to bearing clearance: .001 to .002″
Spark control manual advance: 20° (28° crankshaft travel)
Rotor end cap to distributor body terminal: .020″
Ignition current: .62 amps at 6.2 volts – engine at 1500 rpm; 4 amps at 6.2 volts (engine stopped)

CARBURETOR

Throat size: 1″
Float level: 5/8” below upper body machined surface (Model B, 33/64″ below body machined surface)
Main jet: .037″ LD. (No. 63 drill bit)
Cap Jet: .037″ I.D.
Compensator jet: .035” I.D. (No. 65 drill bit)
Idling jet: .021″ I.D. (No. 75 drill bit)

OIL PUMP & LUBRICATION

Type: Pump. splash. gravity feed
Crankshaft bearing: gravity feed
Connecting rods: splash
Camsl1af1 bearings: gravity feed
Oil pump type: gear
Oil pump capacity: 9 pints/min at 1300 rpm
Oil Pump pressure: 80-100 lbs.
Oil pump shall: 1/2” diameter (in 5/8″ bore). except 1928’s with 9/16” bore and undercut shaft
(Model B used 5/8” bore with undercut shaft.)
Oil pump gear teeth to housing clearance: .001 to .002″
Housing cover to face of gears clearance: .001 to .002″
Drive gear to camshaft gear clearance: .003 to .005″

FLYWHEEL

Weight: 63 lbs.  4 oz. (Model B: 52 to 55 lbs.)
Balance: Within .15 inch/oz.
Ring gear shoulder diameter: 12.470”
Model Ring gear outside diameter: 12.2″
No. of ring gear teeth: 112
Ring gear to starter drive ratio: 11.2 to 1
Flywheel bolt torque: 65 ft./lbs.
Pilot bearing holes concentric with crankshaft flange shoulder within .002 TIR (total indicator reading)
Clutch mounting surface and clutch disc surface must run true to crankshaft within .005″: TIR
Clutch mounting shoulder diameter must be concentric with crankshaft flange diameter within .005″ TIR