Home » Racing Engines » Cadillac V8 OHV 331
Specifications
Cadillac V8 OHV 331 genereation I, V8 (90o) cyl, 4 stroke, petrol engine
Introduced in 1949
Cadillac 331 OHV Technical information
Dimensions
Cylinders arrangement: V8 with 90ยบ included angle
Strokes: 4
Bore x Stroke:
96.8375 x 92.075 mm (3.8125" x 3.625")
Capacity: 5425.1 cc, 331ci
Construction materials
cast iron block 268.2 mm deck height, 115.9 mm (4.5625") bore spacing
steel head
steel crankshaft with 5 main bearings 63.5 mm (2.5") diameter, 57.1mm (2.249") big end bearing diameter
connecting rod distance center to center 168.3 mm
Cylinder-head
side camshaft in block with overhead valves (OHV). 2 valves per cylinder - 16 valves total
Aspiration
Natural
- 2 x Carter WCD 722S two-barrel carburetor
- 2 x Carter WCD 845S two-barrel carburetor
- 2 x Rochester BB two-barrel Model 7004200 carburetor
Ignition
Spark Plug: AC
Firing Order: 18436572 (front to rear: Right bank 2-4-6-8, left bank 1-3-5-7)
1949: 6 volts
1951: 12 volts
negative ground
Cooling and lubrication
Water cooled
wet sump
Models used and Output
| Year | Model, Engine | Induction | Compression ratio | Power | Torque |
|---|---|---|---|---|---|
| 1950 | Allard J2 | 2 x Carter WCD 722S carb | 7.5:1 | 158 HP / 118 kW @ 4000 rpm | 423 Nm / 312 ft-lb @ 1800 rpm |
| 1951 | Allard J2X | 1 x Carter WCD 845S two-barrel or 1 x Rochester BB 7004200 carb |
8.25:1 | 210 @ 4150 rpm | 330 Lbs.Ft @ 2700 rpm |
| 1952 | Allard J2X LM | 2 x Rochester Carbs | 9.0:1 | 250 HP @ 4600 rpm | 345 ft-lb @ 2800 rpm |
| 1953 | Allard J2R | 2 x Rochester Carbs | 10.0:1 | 300 bhp / 224 KW HP @ 5000 rpm | 508 Nm / 375 ft-lb @ 2800 rpm |
Photos
Source
Source
SourceCarter WCD 722S carburetor
SourceCarter WCD 845S carburetor
SourceRochester BB 7004200 flange kit
Service features
| Year | 1949 | 1951 | 1952 | |
|---|---|---|---|---|
| Normal Oil Pressure | 35 Pounds | |||
| Spark Plug | AC 48X | AC 46-5 | AC 44-5 | |
| Spark Plug gap | 0.035" gap | |||
| Timing Mark | "A" mark for premiurm fuel; "C" mark for regular fuel; location: Vib. Damper | |||
| Engine Idle Speed (rpm), Standard transmission | 375 | 450 (in drive) | ||
| Engine Idle Speed (rpm), Automatic transmission | 375 | 400 (in drive) | ||
| Cylinder Head Torque Lbs.Ft. | 65-70 | |||
| Compression Pressure & Cranking Speed | 140 | 150 | 165 | |
| PISTON AND RING SPECIFICATIONS | ||||
| Fitting Pistons with Scale Pistons removed from above | Shim thickness: .002 | |||
| Pounds on a Pull Scale | 11 | |||
| Ring End Gap (In tapered cylinder bores, fit rings in tightest portion of ring travel) | ||||
| Compression Ring End Gap | .007 | .010 | ||
| Oil Ring End Gap | .007 | .010 | ||
| Compression Ring Clearance in Groove | .0022-0035 | .0017-.0035 | ||
| Oil Ring Clearance in Groove | .0015-.003 | .0015-.003 | ||
| Wristpin Diameter, Inch | 1.000 | |||
| VALVE SPECIFICATIONS | ||||
| Operating Clearance, Intake / Exhaust | 0 / 0 | |||
| Valve Seat Angle, degrees | 44 | |||
| Valve Timing: (BTDC = before top dead center; ATDC = after top dead center) | ||||
| Intake opens | 15 BTDC | 19 BTDC | ||
| Exhaust Closes | 40 ATDC | 30 ATDC | ||
| Valve Spring Pressure Pounds at Inches Length | ||||
| Inner Spring | 60 @ 1-11/16 | |||
| Intake Valve Stem Clearance | .001-.0025 | .0005-.0025 | ||
| Exhaust Valve Stem Clearance | .0015-.0035 | .001-.0025 | ||
| ENGINE BEARING SPECIFICATIONS | ||||
| Connecting Rod Bearings | ||||
| Journal Diameter, Inches | 2.2488-2.2493 | |||
| Bearing Clearance, Inch | .0005-.002 | |||
| Rod End Play, Inch | .008-.014 | |||
| Rod Bolt Tension: Lbs.Ft. | 40-45 | |||
| Main Bearings | ||||
| Journal Diameter, Inches | 2.4990-2.4995 | |||
| Bearing clearance | .0008-.0025 | |||
| Shaft End Play | .001-.005 (Thrust on Rear Bearing) | |||
| Main Bolt Tension: Lbs.Ft. | 90-100 | |||
| CAPACITY DATA | ||||
| Cooling System (Without heater) | 18 quarts | |||
| Cooling System (With heater) | 19 | Series 60, 62, 75: 20-1/3 quarts Series 75: 22-4/5 quarts |
||
| Fuel Tank | 20 gallons | |||
| Engine Oil | 5 quarts | |||