Crank Trigger Wheel Flying Magnet Bbc 8 In. Replacement Wheel For Crank Trigger Kit (P/N: 8620) MSD IgnitionFor a long time, racers have known that one of the best things to do to an engine to improve its performance is to stabilize the ignition timing. The MSD Flying Magnet Crank Trigger systems do exactly that by using four magnets embedded in an aluminum wheel. Although similar in appearance to other crank triggers, the MSD Flying Magnet design works on a different principle. Most crank triggers have a wheel, with steel studs sticking out, bolted to the