1949 to 53 Tune-Up OEM Specifications
239 and 255 Cubic Inch Flathead

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Note: Ford specs are in black and Mercury specs are in red
Year Model Displacement Cubic Inches HP Compression Ratio Compression Pressure Spark Plugs
1949 8BA 239.4 100 6.80 110 Champion H10 .030"
1949 9M 255.4 110 6.80 115 Champion H10 .030"
1950 0BA 239.4 100 6.80 110 Champion H10 .030"
1950 0M 255.4 110 6.80 115 Champion H10 .030"
1951 1BA 239.4 100 6.80 120 Champion H10 .030"
1951 1M 255.4 112 6.80 115 Champion H10 .030"
1952 B2 239.4 110 7.20 125 Champion H10 .030"
1952 BC 255.4 125 6.80 115 Champion H10 .030"
1953 B3 239.4 110 7.20 125 Champion H10 .030"
1953 BG 255.4 125 6.80 115 Champion H10 .030"

All Specifications are per Motor's Auto Repair Manual and/or Ford-Mercury Shop Manual

Year Ford Model   Valve Clearances *  Exhaust         Intake Ignition Timing Engine Idle Speed Manual      Autom. Breaker Gap (inches) Dwell Angle (degrees)
1949 8BA .014-.016" .010-.012" 2 BTDC 475 440 .014-.016 28
1949 late 8BA .017-.019" .013-.015" 2 BTDC 475 440 .014-.016 28
1950 0BA .017-.019" .013-.015" 2 BTDC 475 440 .014-.016 28
1951 1BA .017-.019" .013-.015" 2 BTDC 475 440 .014-.016 28
1951 1BA .017-.019" .013-.015" 2 BTDC 475 440 .014-.016 28
1952 B2 .017-.019" .013-.015" 2 BTDC 475 440 .014-.016 28
1953 B3 .017-.019" .013-.015" 2 BTDC 475 450 .014-.016 28

  Note: Valve (exhaust and intake) clearances on the flathead V8 engine are set COLD ( * )

  Mercury tune up specifications are the same as Ford specs shown above and below except as noted in red color.

  Note: Valve specs shown here are from the Ford Service Manuals (1949-51 and 1952). The MOTORS MANUAL differs slightly on valve clearance specs.

Note (*): Valve clearances on the flathead V8 are set COLD.

Loadamatic Distributor Specifications
(per Motor's Auto Repair Manual)

Year Distributor Distributor Vacuum Advance Specifications
    AT 500 RPM AT 1000 RPM AT 1500 RPM AT 2000 RPM
    Degrees Advance Inches Vacuum Degrees Advance Inches Vacuum Degrees Advance Inches Vacuum Degrees Advance Inches Vacuum
1949 to early 1950 7RA-12127C 1-2 0.40 4-5 1.70 6-7 2.80 7-8 3.70
Late 1950 to 1953 8BA-12127 0-1 0.30 5-6 1.32 8-10 2.85 10-11 3.70
Late 1950 to 1953 0BA-12127 0-1 0.30 5-6 1.32 8-10 2.85 10-11 3.70
1949-53 7RA-12127C 1-2 0.40 4-5 1.70 6-7 2.85 7-8 3.70

Note: A 3/8" x 24 adapter may be fitted to the carburetor for your vacuum gauge

Timing Mark: Groove on front pulley
Distributor Rotation: Clockwise
Cylinder Numbering (front to rear): Right Bank: 1-2-3-4     Left Bank: 5-6-7-8     
1-5-4-8-6-3-7-2
Condenser Capacity: 0.21 to 0.25 microfarads
Breaker Spring Arm Tension: 17 to 20 oz.

distr-sparkplugwiring_49-53v8.jpg (144549 bytes)

Adjusting Ignition Timing

When checking engine timing with a strobe type timing light, disconnect the vacuum line from the carb to the distributor. Engine should be at idle speed. Connect timing light high voltage lead to wire going to Number 1 spark plug and the appropriate low voltage leads to the battery connections per timing light instructions. Be sure to check polarity of connections....stock electrical systems are 6 volt positive ground. Loosen distributor hold-down bolt and adjust timing by twisting distributor until timing marks line up between groove on pulley and indicator. Tighten distributor hold-down bolt and re-check timing. Re-connect vacuum line to distributor.

Spark advance in the LoadaMatic distributor is controlled entirely by the vacuum differential at the carburetor, which regulates the vacuum control diaphragm on the distributor. The diaphragm is connected to the breaker plate and works against two springs. On 1949 Ford distributors the two springs are of separate tension. 1950 to 53 distributors have identical springs. The springs are mounted on posts with eccentric mounts. Turning the post adjusts the spring tension. Vacuum for the LoadaMatic distributor does not come from a simple vacuum fitting off the intake manifold (ie for windshield wipers), but must come from the vacuum connection on the carburetor. The stock Ford/Holley carb has the necessary two vacuum circuits internally, that are absolutely necessary for control of this distributor. In general, earlier Stromberg carbs will not have these vacuum circuits that would allow them to be used on the 49-53 distributor. Likewise, when using multiple carburetor manifolds, there will not be sufficient air velocity in either carb to operate the vacuum advance of this distributor correctly. Most builders who use aftermarket manifolds and carbs will convert the ignition distributor to the earlier "crab" type with its vacuum brake advance mechanism. We have no recommendations at this time relating to use of other after-market distributors or ignition systems.

When setting breaker point gap be sure to check ignition timing after making the adjustment. There is an oiler on the stock distributor body to provide lubrication for the distributor drive shaft. Also, a light film of breaker point grease should be applied to the eight-sided cam (or rubbing block) when the points are serviced.

The condenser is rated at 0.21 to 0.25 microfarads. This can be checked properly with a meter designed to read condensers and capacitors. A simple ohmmeter can test for complete failure, but will not give an accurate reading for specified ratings. If moving a condenser to a more remote location than its original mount in the distributor, be sure to check its rating with the longer lead wire.

We stock engine tune-up parts for the 1949-53 flathead V8 engines. Click here for available items.

Picture of Typical 1949-53 Distributor

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