ing coil

[hpk 53]

Ing resiator # 2 instaled new resiator what is the coil volts is it 6v or lower .

[hueyhoolihan]

i've had problems with the ignition (1941, is missing terribly, almost undriveable) after the engine warms up. have installed rebuilt helmet distributor and a new coil from one of the aftermarket vintage ford outfits. didn't help and now am not getting no spark at all. ...i suspect the new coil has been fried. so basically a waste of time and money.

my next step is to install one of those adaptor kits that permits the use of a slightly more modern canister type coil (which i bought a while back from e-fire) while still using the helmet distributor. ...we'll see how THAT works.

FYI, still running the positive 6v system. don't know if there's an artificial resistance added (aka ballast resistor?) when the engine is running, but absent when starting. which is how i understand that it works.

in any event, i plan on running a wire straight from the battery to the new canister (so as to bypass any ballast resistor in the wiring) style coil and then to the adaptor cap that is part of the kit.

[JayChicago]

Originally Posted by hpk 53

Ing resiator # 2 instaled new resiator what is the coil volts is it 6v or lower .

If the engine happened to stop with points open, voltage at the coil will just be battery voltage, 6.0-6.5 volts. That tells you nothing. Bump the starter one time to get the points closed and take another reading.

The ignition resistor produces a 3 volt drop. So depending on your battery condition, you should measure voltage at the coil about 3.0-3.5 volt.

Later with engine running, points open 20% of the time, the averaged voltage at the coil will jump up to about 4 volts.

BTW, don't forget to turn-off the ignition switch after each test. While engine is stopped with points closed there is maximum current is flow. Can cook that little coil.

[JayChicago]

Originally Posted by hueyhoolihan

don't know if there's an artificial resistance added (aka ballast resistor?) when the engine is running, but absent when starting. which is how i understand that it works.

That technology, (ballast resistor by-passed during cranking) came about in fifties. Our resistor doesn't do anything to help starting, is in the circuit at all times.

Resistor is there simply to limit the current running through the little coil. As told by RotorWrench in a previous post, when Henry insisted on a distributor-mounted coil, which had to be in a small package, they had to limit the current by use of an external resistor.