Speaking of coils

[katy]

Anyone know what would be the output (spark) voltage of a stock Model a coil?
TIA

 

[Canton_Model_A's]

From a google search:

The ignition coil in a Ford Model A, like many ignition coils, steps up the 6V or 12V battery voltage to a high voltage spark (around 20-35 kV) required to jump the gap in a spark plug. The Model A ignition coil is a transformer, typically with a 100:1 or higher turns ratio between the primary and secondary windings, achieving this high voltage.

 

[JayJay]

From a google search:

The ignition coil in a Ford Model A, like many ignition coils, steps up the 6V or 12V battery voltage to a high voltage spark (around 20-35 kV) required to jump the gap in a spark plug. The Model A ignition coil is a transformer, typically with a 100:1 or higher turns ratio between the primary and secondary windings, achieving this high voltage.

That sounds like AI, highly reliable (like the one recently that postulated that Deluxe cars had fewer fins in the hood...).

 

[nkaminar]

You can measure the amount of voltage your coil is putting out. Online references say it takes 30,000 volts to jump a gap in air of 1 cm. You can set up a tester with some copper wire that can be bent to provide a gap. Or you can just hold the end of the coil from the coil near the head with insulated pliers. Increase the gap in small steps until the coil cannot jump the gap. Measure the gap and ratio it to 1 cm. So a 1.2 cm gap would indicate you coil is putting out 1.2 X 30,000 or about 36,000 volts. You can open the points with a piece of wood or your finger to create a spark.

Because the plug is operating with increased air pressure, it takes more voltage to jump the gap. Coils put out about 30,000 volts for normal cars. For top fuel dragsters the voltage is much greater and the spark plug gap is much larger. The electrodes are burned away after each race and the plugs are replaced.

https://www.quora.com/How-many-volts-does-it-take-for-electricity-to-jump-to-another-metal-object