[johnneilson]

Interesting discussion about multi plug engines, some dyno testing has shown the Yapp Lion head likes just a bit of stagger between the firing of the plugs.

Brass era cars had multiple plugs, this is a Buddy's Pierce Arrow Roadster small inline six (540 cu in approx)
It has 3 plugs per cylinder, a mag that fires 2 and dist for 1.

Dist is used for starting and turned off once running.