How does the 123ignition function? In a 123 ignition distributor, all moving parts – like the original points, the centrifugal weights, the springs, the bearings and the vacuum-diaphragm – have been replaced with just one moving part: the central shaft with the rotor. The internal electronics provide the right advance and the optimum dwell-angle throughout the rev. range to maintain peak energy and peak performance. There is no wear altering the timing of the 123ignition: once set, you’ll never have to worry about it again! With a little switch behind an opening in the billet-housing, you can select the best advance-curve for your engine. This version with pre-programmed advance curves therefor also is called the ‘switch’ version. Please select the right brand below to see which 123 ignition products are suitable for your classic car.