The ignition load on an SI engine isn't "that" significant - you can get a battery operated Tazer that'll produce quite a significant spark for a fair length of time off of a few cells.
You can flick the magneto on a small engine and get two significant sparks with only a "few" joules of energy.
Higher calorific values, higher compression ratios and more effective operating temperatures of CI engines and diesel fuel are more significant.
You can flick the magneto on a small engine and get two significant sparks with only a "few" joules of energy.
Higher calorific values, higher compression ratios and more effective operating temperatures of CI engines and diesel fuel are more significant.