I want to measure the position of the crankshaft with my homemade car computer and compare it to the signal from the no. 1 spark plug so I can measure the engine timing while driving. I was thinking the best way to do this would be to use JB Weld and glue 2 magnets to either side of the harmonic balancer so there would be 1 magnet at the 0 degrees TDC and another 180 off. Then use a hall-effect switch mounted near the magnets. Of course, I would be getting 4 signals from my make-shift CPS for every signal from the no. 1 spark plug, but the firmware would have to account for that.