Ngk plug gap

[KiWinUS]

Originally Posted by Bored&Stroked

In my opinion the correct plug gap for MOST sparkplugs is driven by the ignition system components, not the plug itself. Most of our older ignitions tend to have plug gaps of around .020 to .025. I set all my flathead (points ignitions) to about .020 to .022. I also set my plug gap at .020 for my Vertex Mags (on flatheads).

On many racing magnetos (like a MSD ProMag), the plug gaps are really small - about .014 to 0.18 or so. This is because at starting RPMs, the ProMag doesn't put out a lot of energy to "jump the gap", but once the spark starts to jump it has a lot more duration than a typical points ignition. The amount of amps a ProMag puts out is amazing - even in the lower 20 amp versions. The top-fuel boys fun dual 44 amp ProMags.

Another tip --> do not run resistor plugs or wires on our early ignitions . . . too much resistance is put into the secondary and all sorts of erratic spark events can occur.

Totally agree with everything Dale stated here. This “low voltage ignition “ for lack of a better term works very well with all the correct components in working condition.