Throwing my hands up on this ignition!
Spark gap is a variable. Other variables are how well the fuel air mixture has been prepared and developed in the immediate location of the the spark plugs. Things like heat and compression play into that too.
Immediately after initiation, spark voltage drops dramatically. Most of the duration of the spark is at this lower voltage, usually called the spark line.
How much voltage is needed to initiate, and how much power (voltage x amps) is needed to keep the kernal of flame growing so the rest will burn well depends mostly on what is going on in the combustion chamber.
Shrinker summarizes flame development in depth here: Motorsports Village • View topic - Dyno time
Maybe post these questions about observing spark electric voltages and currents in Kit's thread about 'scopes.
Using a Scope for Diagnostics
Off the top of my head, initiation can be anywhere from 10 K to 15KV, but sometimes higher.
Spark gap is a variable. Other variables are how well the fuel air mixture has been prepared and developed in the immediate location of the the spark plugs. Things like heat and compression play into that too.
Immediately after initiation, spark voltage drops dramatically. Most of the duration of the spark is at this lower voltage, usually called the spark line.
How much voltage is needed to initiate, and how much power (voltage x amps) is needed to keep the kernal of flame growing so the rest will burn well depends mostly on what is going on in the combustion chamber.
Shrinker summarizes flame development in depth here: Motorsports Village • View topic - Dyno time
Maybe post these questions about observing spark electric voltages and currents in Kit's thread about 'scopes.
Using a Scope for Diagnostics