1949 Oldsmobile 303 V8 Engine Specs

About This Site

GENERAL SPECIFICATIONS

Model Designation: 88, 98

Wheel base: 88: 119-1/2; 98: 125

Valve Location: In Head

Bore and Stroke: 3-3/4 x 3-7/16

Piston displacement, Cubic Inches: 303.7

Compression ratio: 7.25

Maximum Brake Horsepower: 135 @ 3600 RPM

Maximum Torque Lbs.Ft. @ RPM: 263 @ 1800 RPM

Normal Oil Pressure Pounds: 40

TUNE UP SPECIFICATIONS (all models)

Spark Plug Make: AC 46-5

Spark Plug Gap, Inch: .030

Firing Order: 18736542 (left bank: 1-3-5-6; right bank: 2-4-6-8)

Timing Mark: between 2 balls or slot, location: pulley

Engine Idle Speed, RPM: Standard transmission: 425; w/automatic 375 (in drive)

Cylinder Head Torque Lbs.Ft.: 60-70

Compression Pressure & Cranking Speed: 120

Voltage & Polarity: 6 volts, negative ground

PISTON AND RING SPECIFICATIONS

Fitting Pistons with Scale: Pistons removed from above. Shim thickness: .0015

Pounds on a Pull Scale: 10 to 18

Ring End Gap: In tapered bores, fit rings in tightest portion of ring travel
Compression: Sealed Power: .008; Perfect Circle: .010
Oil: Sealed Power: .008; Perfect Circle: .010

Clearance in Groove: Compression: .001-003; Oil: .001-.0025

Wristpin Diameter, Inch: .9803-.9807

VALVE SPECIFICATIONS

Operating Clearance:
Intake: 0 Exhaust: 0

Valve Seat Angle, degrees: 45

Valve Timing: (BTDC = before top dead center; ATDC = after top dead center)
Intake opens: 13-1/2 BTDC
Exhaust Closes: 14-1/2 ATDC

Valve Spring Pressure Pounds at Inches Length:
Inner Spring: 65 @ 1-3/4

Valve Stem Clearance: Intake: .002-.004; Exhaust: .0025-.0045

Clearance for Timing Intake: 0

ENGINE BEARING SPECIFICATIONS

Connecting Rod Bearings:
    Journal Diameter, Inches: 2.488-2.2498
    Bearing Clearance, Inch: .0009-.0029
    Rod End Play, Inch: .002-.011
    Rod Bolt Tension: Lbs.Ft.: 45-50

Main Bearings:
    Journal Diameter, Inches: Nos. 1, 2, 3, 4: 2.498; No. 5: 2.623-2.624
    Bearing clearance: For Rear Main: .002-.0035; others: .0005-.003
    Shaft End Play: .004-.008    (Thrust is taken at rear bearing)
    Main Bolt Tension: Lbs.Ft.: Rear: 140 ft/lbs; all others: 100 ft.lbs

CAPACITY DATA

Cooling System:
Without heater: 21-1/2 quarts
Without heater: 22-1/2 quarts

Fuel Tank: 18 gallons

Engine Oil: 5 quarts

Transmission: w/out overdrive: 2 pints; Automatic: 11 quarts

Rear Axle: 3-3/4 pints

DELCO-REMY DISTRIBUTOR SPECIFICATIONS

Distributor part number: 1110814 (distributor rotates counter-clockwise)

Cam Angle, degrees: 21-30

Breaker Point opening, Inch: .016

Condenser Capacity: .18-.23 Mfds.

Breaker Arm Spring Tension: 19-23 Oz.

Centrifugal Advance: (degrees at RPM of distributor)
    Advance starts: 2 @ 400 RPM
    Full Advance: 16 @ 1850 RPM
    Inches of Vacuum to Start Plunger Movement: 6-1/2 - 8-1/2
    Inches of Vacuum for Full Plunger Movement: 19-21
    Maximum Vacuum Advance Dist., Degrees: 10

DELCO-REMY GENERATOR SPECIFICATIONS

Generator Number: 1102706, 1102707 (generator rotates clockwise, 6 volts, Negative Ground)

Generator output: 40 amps @ 2150 RPM

Brush Spring Tension: 28 oz.

Field Current at 6 Volts: 1.87-2.0

DELCO-REMY REGULATOR SPECIFICATIONS

Regulator Number: 1118300

Cutout Relay:
    Voltage to close points: 6.4
    Reverse current to open points: 0-3
    Armature Air Gap: .020

Voltage Regulator Setting: 7.3 volts

Current and Voltage Armature Air Gap: .075 inches

Current Regulator Setting: 42 amps

DELCO-REMY STARTING MOTOR SPECIFICATIONS

Part number: 1107956 (rotates clockwise)

Bush Spring Tension, Ounces: 24-28

No Load Test: 60 amps, 5.0 volts @ 6000 RPM

Torque Test: 600 Amps, 3.0 volts, Torque, Lbs.Ft.: 15

WHEEL ALIGNMENT SPECIFICATIONS

Caster, Degrees
Limits: -3/4 to 0
Desired: - 3/8

Camber, Degrees
Limits: -3/4 to +3/4
Desired: 0

Toe-In, Inches: 1/16 to 1/8

Toe-Out on Turns, Degrees: (If toe-out is incorrect, when other adjustments are correct, look for bent steering arms.)
Outer wheel: 20
Inner Wheel: 22-1/2 to 23-1/2

Kingpin Angle, or Steering Axis Degrees: (If king pin or spindle support angle are incorrect, but camber is correct, look for bent suspension arms or steering knuckle support)
4-1/2