Dual plugs,
This is so combustion happens faster from both sides of the head. Not going from the middle out, but from the 2 sides in.
Not true! The flame front propagates outward in a semi circle shape and this process starts before full compression is achieved at the top of the up stroke as it takes some time for this to complete, the comp forces it to be faster NOT more spark.Dual ignition systems were designed for aircraft engines as a redundancy system to prevent in flight failures and later used by other engine manufactures to aid in emission control,in these cases the spark has a slight delay between them like the Dodge Magnum hemi for cylinder clearing.Our magneto (wire loop) barely produces enough current to fire a single good plug even with a better secondary coil,when tested spark strength if you're lucky may be around 40k usually just under at best where as a strong spark is considered to be well above that,now try to fire two plugs with that same current and it will be far less on each!