Solid wire ignition

the gap works to some extent
and you are right a higher voltage can in some cases produce a spark when a lower voltage won't

in the old days there was always some fella at a car show with a coil, a plug and wire, on a bench, selling a "spark booster" it will have had a nice box a nice price and well yes it certainly does something

(he was on the stall next to the fella with a briggs 2hp motor and a magic oil additive
running the motor at 2000 rpm with no oil.... something they will do quite happily for quite a while, additive added previously or no additive, just a low stress motor that will take ages to seize with no oil)

this was a small box that you put in the king lead and it boosted your spark
his demo was always impressive, you could hear the cracking of the spark,once the box was fitted and its seemed to be quite vicious at the plug as well .

A simple version of the booster plug mentioned above

it was basically a box with 2 pointed contacts facing each other with a small gap two screw terminal ignition lead connectors at either end.

in order for a spark to happen at the plug the voltage in the coil had to build to a much higher level to breach the gap in the box and hence once that gap was jumped the voltage seen at the plug was higher and you got a noiser, and in viewing terms, bigger spark

the problem with this is you waste spark energy making it jump
The gap in the special box
The rotor tip to contact
before it gets to the plug gap

increasing the voltage this way reduces length of time the current flows through the spark at the plug which ultimately is the carrier of the energy across the spark gap

The process basically stresses the coil for a little more performance from a marginal ignition system until your coil fails

the coil is surrounded by a magnetic field that collapses at high speed when the points open or the ignition box switches off

it collapses into the core of the coil that generated it, and makes a current and voltage in the windings around that core.
If the current can't flow, the voltage increases and increases, is pushed to an extreme by the collapsing field......... until a current can flow i.e a spark jumps the gap and starts at the plug

but the coil is made from varnished wire, the higher the voltage goes above specification the more likely the voltage is to find an inconsistency in the varnish and start arching out to the coil case or another compromised winding.

and eventually your coil fails

higher voltage needed to start the spark results in a shorter period of current flow,

it can have benefits i.e less likely to burn out a carbon rotor button

but really its all just better to run the stuff as intended without messing

if the plug gap is supposed to be 30 thou fine
if its supposed to be 45 fine

don't add in an equivalent of another 45 somewhere in the chain

diminishing returns messing with the voltage needed to spark
adjust it slightly by adjusting plug gaps rather than adding in a hurdle


and that's all before we get to arcing to the wrong place in the dizzy and the detrimental effect it has on the cap contacts

Dave