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Second Chance Garage

For the Car Restoration Enthusiast

Second Chance Garage

Second Chance Garage

For the Car Restoration Enthusiast

Second Chance Garage

For the Car Restoration Enthusiast

Second Chance Garage
Rust bullet

ENGINE SPECS

1951 Mercury 255 V8 Engine Specs

GENERAL SPECIFICATIONS

Model Designation: 1M

Wheel base: 118

Valve Location: In block

Bore and Stroke: 3-3/16 x 4

Piston displacement, Cubic Inches: 255.4

Compression ratio: 6.80

Maximum Brake Horsepower: 112 @ 3600 RPM

Maximum Torque Lbs.Ft. @ RPM: 206 @ 2000 RPM

Normal Oil Pressure Pounds: 57

TUNE UP SPECIFICATIONS

Spark Plug Make: Champion H10

Spark Plug Gap, Inch: .030

Firing Order: 15486372 (front to rear: Right bank 1-2-3-4, left bank 5-6-7-8)

Timing Mark: Groove in Pulley

Engine Idle Speed, RPM: 475

Cylinder Head Torque Lbs.Ft.: 65-70

Compression Pressure & Cranking Speed: 115 Min.

Voltage & Polarity: 6 volts, positive ground

PISTON AND RING SPECIFICATIONS

Fitting Pistons with Scale: Pistons removed from above. Shim thickness: .002;

Pounds on a Pull Scale: 6 to 12

Ring End Gap: In tapered bores, fit rings in tightest portion of ring travel
Compression: .007
Oil: .010

Clearance in Groove: Compression: .0015-003; Oil: .0015-.003

Wristpin Diameter, Inch: .7501-.7504

VALVE SPECIFICATIONS

Operating Clearance: Intake: .014 ColdExhaust: .018 Cold

Valve Seat Angle, degrees: 45

Valve Timing: (BTDC = before top dead center; ATDC = after top dead center)
Intake opens: 5 BTDC
Exhaust Closes: 9 ATDC

Valve Spring Pressure Pounds at Inches Length: Inner Spring: 40 @ 1.89

Valve Stem Clearance: Intake: .0015-.003;Exhaust: .002-.004

ENGINE BEARING SPECIFICATIONS

Connecting Rod Bearings: Journal Diameter, Inches: 2.1390
Bearing Clearance, Inch: .0005-.003
Rod End Play, Inch: .006-.020
Rod Bolt Tension: Lbs.Ft.: 45-50

Main Bearings: Journal Diameter, Inches: 2.4985
Bearing clearance: .001-.0026
Shaft End Play: .002-.006(Thrust on Rear Bearing)
Main Bolt Tension: Lbs.Ft.: 90-105

CAPACITY DATA

Cooling System: Without heater: 22 quarts
With heater: 23 quarts

Fuel Tank: 19-1/2 gallons

Engine Oil: 5 quarts

Transmission: w/out overdrive: 3-1/4 pints; w/overdrive: 4-1/4 pints; Automatic: 9 quarts

Rear Axle: 3-1/2 pints

LOADAMATIC DISTRIBUTOR SPECIFICATIONS

Distributor part number: 7RA-12127C (distributor rotates clockwise)

Cam Angle, degrees: 28

Breaker Point opening, Inch: .014-.016

Condenser Capacity: .21-.25 Mfds.

Breaker Arm Spring Tension: 17-20 Oz.

Vacuum Advance: (degrees at RPM of distributor)
At 500 RPM: 1-1/4 - 2-1/4 Degrees advance; .4 Inches Vacuum
At 1000 RPM: 4-1/2 - 5-1/4 Degrees advance; 1.7 Inches Vacuum
At 1400 RPM: 6-1/4 - 7-1/4 Degrees advance; 2.8 Inches Vacuum
At 2000 RPM: 7-1/2 - 8-1/2 Degrees advance; 3.7 Inches Vacuum

GENERATOR SPECIFICATIONS

Generator Number: 8BA-10000B (generator rotates clockwise, 6 volts, Positive Ground)

Generator output: 36 @ 1700 RPM

Brush Spring Tension: 30 oz.

REGULATOR SPECIFICATIONS

Regulator Number: 8M-10505A

Cutout Relay: Voltage to close points: 6.3
Reverse current to open points: 0-8

Voltage Regulator Setting: 7.3 volts

Current Regulator Setting: 30 amps

STARTING MOTOR SPECIFICATIONS

Part number: 7RA-11001

Bush Spring Tension, Ounces: 48-56

No Load Test: 70 amps, 6 volts @ 3000 RPM

Torque Test: 700 Amps, 3.5 volts, Torque, Lbs.Ft.: 16

WHEEL ALIGNMENT SPECIFICATIONS

Caster, Degrees
Limits: -1 to +1/2
Desired: -1/4

Camber, Degrees
Limits: 0 to +3/4
Desired: +3/8

Toe-In, Inches: 3/32 to 5/32

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: 23 to 24

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) 5 @ 3/4 Camber