In Reply to: Re: Front mount coil posted by Bruce (VA) on May 12, 2017 at 07:34:08:
Another thing to keep in mind is that copper windings of coil increase resistance as coil/copper heats up, thus reducing current and spark energy as temperature increases. Actually, with no other outside influences, energy can fall to only 60% of cold start value as it reaches fully hot running temperature strictly due to resistance increase if coil windings.. Now, as a "for instance", let us say that various things are marginal in the engine, maybe mixture, compression, points, condenser, plugs, plug wires, state of battery charge, on & on, but spark is just good enough to make it run even with its problems, but as temperature increases, the spark drops from 100% (cold), to 90%, then 75% and finally drops below what it needs to be to keep the engine running fine. Whereas if all engine systems were perfect, it might "run fine" with a spark of 60%. Food for thought.