Denny, The point sets are wired so that if either set is open, the coil is being energized. The coil's ground is completed only when both sets are closed, that's when the coil discharges, creating a spark. So, with more 'build-up' time, you should get a hotter spark when it discharges. Higher voltage sparks are required to ignite leaner mixtures & in higher compression ratio conditions. At slower RPM's the coil has enough saturation time to reach its maximum output voltage using only one point set. At somewhere around 4,000 to 6,000 RPM the 'dual-point' setup becomes a definite asset. Note-there were other, some OEM, & some aftermarket, distributors made with dual point sets & these used a dist. cam with 1/2 the number of lobes as there were cylinders. They used two coils, ea. point set triggering its own seperate coil. With only 1/2 the number of cam lobes, it could be shaped to allow more sat. time. Doug
