| ewall | -- 07-07-2014 @ 1:15 PM |
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What causes a hot coil
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| 40 Coupe | -- 07-08-2014 @ 3:52 AM |
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If you have a sock Ford system either the coil is going bad or the resistor that limits the current to the coil is shorted or missing. If the system is modified, usually too much current is allowed in the coil circuit. This excessive current just heats up the coil. If you still have a point distributor, the current in the coil circuit should be between 3.5 to 4.5 Amp. anything above this will cause excessive wear on the points and heating of the coil resulting in early coil failure. Measure the ohmage of the coil secondary as well as the resistance of the ignition resistor add the two together then I(coil circuit current)=7.0/R(resistance of the ignition circuit) to limit the current to 4.0A the resistance should be approximately 1.75 Ohm.
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| JM | -- 07-08-2014 @ 9:13 AM |
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A hot coil can also be caused by shorted windings/turns within the coil. The insulation used in these coils back in the day, 70-80 years ago, are so inferior to todays insulations, that IMO, any of these original coils are suspect and should be rewound with modern components and insulations. Skip Haney in Punta Gorda, FL does an excellant job on this type of rewind. I would not leave my driveway in my old Ford without one of his rewound coils on the distributor. John
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| carcrazy | -- 07-08-2014 @ 9:57 AM |
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If you are using an aftermarket coil which has an internal resistor, the heat is generated in the resistor.
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| EFV-8 Club Forum : | https://www.earlyfordv8.org/forum |
| Topic: | https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=7488 |