The Stovebolt Site Forums The Shop Area The Electrical Bay Appropriate plug wires with electronic ignition install

The resistance of a metal core wire is so low that there's enough current flow to damage the secondary windings of a "high voltage" coil. For a few milliseconds there's the equivalent of a dead short across the secondary until the inductive reactance of the windings kick in to limit the current

There will be plenty of spark, but the voltage cannot rise above the 8KV to 12KV that's required to ionize the gap, no matter what the "open circuit" capacity of a high voltage coil might happen to be. Once the spark starts to flow across the gap, the voltage cannot rise any higher. Therefore, it's IMPOSSIBLE to get 40KV applied to anything other than a disconnected spark plug wire that's hanging out where there's nowhere for the spark to find a ground.