Classic Car Engine Specs: 1954 Pontiac 268 (127 hp) Inline Eight

GENERAL SPECIFICATIONS

Year: 1954
Model Designation: Chiefton 8 with Hydramatic Transmission 54-28, Star Chief 8 with Hydramatic Transmission 54-28
Wheel Base: 122
Valve Location: In Block
Bore & Stroke: 3.3750 x 3.750
Piston Displacement, Cubic Inches: 268.4
Compression Ratio 7.7
Maximum Brake HP @ RPM: 122 @ 3800
Maximum Torque Lbs. Ft. @ RPM: 234 @ 2200
Normal Oil Pressure Lbs: 35

TUNE UP SPECIFICATIONS

Disconnect vacuum line when using timing light to set timing.
Ground Polarity & Voltage: N-6
Spark Plug Type: A.C. 44-5 Tighten to a torque of 15-25 lbs. ft.
Spark Plug Gap, Inch: .025
Distributor:
Point Gap, Inch .016
Cam Angle Degrees: 21-30
Firing Order: 16258374
Ignition Timing:
Timing Mark: When cranking engine first line to come under pointer is for std. head & second line for high compression head.
Timing Mark Location: Damper
Idle Speed RPM in Neutral: 450-475
Compression Pressure @ Cranking Speed Minimum: 139

VALVE SPECIFICATIONS

Running Clearance:
Int: .012H
Exh: .012H
Valve Seat Angle, Degrees: Intake 30 degrees exhaust 45 degrees.
Valve Timing (-BTDC: Before top dead center. ATDC: After top dead center.)
Intake Opens Deg. BTDC: 5
Exhaust Closes Deg. ATDC: 5
Valve Spring Pressure Lbs. at Inches Length: 105 @ 1 13/32
Valve Lift Zero Lash
Int: .2968
Exh: .2968
Stem Clearance:
Int: Guides taper .001" to the inch and when started in the guide the valve should fall through of its own weight.
Exh: Guides taper .001" to the inch and when started in the guide the valve should fall through of its own weight.
Stem Diameter, Std.
Int: .310-.311
Exh: .310-.311

ENGINE TIGHTENING SPECIFICATIONS

Torque specifications are for clean & lightly lubricated threads only. Dry or dirty threads produce increased friction which prevents accurate measurement of tightness.
Spark Plugs Ft. Lbs.: 25
Cylinder Head Bolts Ft. Lbs.: 60
Connecting Rod Cap Bolts Ft. Lbs. 45
Main Bearing Cap Bolts Ft. Lbs.: 95 (Rear 120.)
Flywheel to Crankshaft Ft. Lbs.: 105
Vibration Damper or Pulley Ft. Lbs.: 95

COOLING SYSTEM & CAPACITY DATA

Cooling System Data
Quarts No Heater: 18 3/4
Quarts With Heater: 20 1/2
Rad. Cap Relief Pressure: 6 1/2 - 7 1/2
Thermostat Opening Temp
-For permanent type anti-freeze: 170
-For alcohol type anti-freeze: 151
Fuel Tank Gals: 20
Engine Oil
Refill Quarts: (-Add one quart with filter change): 5
Summer Grade: 20
Winter Grade: 10W
Transmissions
Automatic Qts.: 11
Rear Axle Pints: 3 1/4

DISTRIBUTOR SPECIFICATIONS

Part No. (Stamped on plate riveted to side of Distributor housing): 1110831
Rotation: (-As viewed from top. CC-Counter Clockwise): CC
Cam Angle Degrees: 21-30
Breaker Point Opening, Inch: .016
Condenser Capacity, Mfds. (-Microfarads-as indicated on a condenser tester.): .18-.23
Breaker Arm Spring Tension, Ounces: 19-23
Centrifugal Advance Data Degrees @ RPM of Dist.
Advance Starts: 1 @ 400
Full Advance: 11 @ 1950
Vacuum Advance Data
Inches of Vacuum to Start Plunger Movement: 7-9
Inches of Vacuum for Full Plunger Travel: 20 1/2
Maximum Vacuum Advance, Dist. Degrees: 10

PISTON, PINS, RINGS, CRANKSHAFT & BEARINGS

Ring End Gap (-Fit rings in tapered bores for clearance given in tightest portion of ring travel)
Comp: .008
Oil: .008
Wristpin Diameter: .9372
Rod Bearings
Shaft Diameter: 1.9987-1.9997
Bearing Clearance: .0001-.002
Main Bearings
Shaft Diameter: No. 1, 2.3732-2.3742, No. 2, 2.4044-2.4254, No. 3, 2.4357-2.4367, No. 4, 2.4669-2.4679, No. 5, 2.4982-2.4992
Bearing Clearance: .0003-.0023
Thrust on Bear. No.: 4
Shaft End Play: .003-.008

GENERATOR & REGULATOR SPECIFICATIONS

Generator
Generator Number: 1102794
Rotation: & Ground Polarity (-C-Clockwise. N-Negative): C-N
Generator Output
Amperes: 45
RPM: 2350
Brush Spring Tension, Ounces: 28
Field Current Amperes: 1.87-2.0 (At 6 volts)

Regulator
Regulator Number: 1118827
Cutout Relay
Voltage to Close Points: 6.3
Armature Air Gap, Inch: .020
Voltage Regulator Setting Volts: 7.1
Current Regulator Setting Amperes: 44
Current & Voltage Armature Air Gap, Inch: .075

STARTING MOTOR SPECIFICATIONS

Part No: 1107107, 1107957
Rotation: (-As viewed from drive end): C
Brush Spring Tension, Ounces: 24 Min.
No Load Test
Amperes: 1107107 - 70, 1107957 - 80
Volts: 1107107 - 5.65, 1107957 - 5.67
RPM: 5500
Torque Test Amperes: 1107107 - 550, 1107957 - 600
Volts: 1107107 - 3.25, 1107957 - 3.0
Torque, Lbs.Ft: 1107107 - 11, 1107957 - 14

REAR AXLE & BRAKE CYLINDER SPECIFICATIONS

Ring, Gear & Pinion Backlash, Inch: .003-.012
Drive Pinion Adjustment: Shim
Drive Pinion Bearing Adjustment: Spacer
Axle Shaft End Play, Inch: None
Hydraulic Cylinder Bore Sizes, Inch:
Wheel Cylinder: Front: 1 1/16; Rear: 7/8
Master Cylinder: 1

WHEEL ALIGNMENT SPECIFICATIONS

Caster, Degrees: Limits: -1/2 to +1/2
Desired: 0
Camber, Degrees: Limits: 0 to +1
Desired: +1/2
Toe-In, Inches: 0 to 1/16
Toe-Out on Turns, Degrees: (-Incorrect toe-out, when other adjustments are correct, indicates bent steering arms)
Outer wheel: 18 1/2
Inner Wheel: 20
Kingpin Angle, Degrees: (-Incorrect kingpin angle with correct camber indicates bent suspension arms or steering knuckle support): 4 1/2 to 1/2 CAMBER