Hi. I am looking for a sensor that can measure the position of a flywheel of an engine.

Usually this is done with inductive sensors or hal sensors however my engine has 4 magnets on the flywheel so I think those would interfere with the signal I need.

The sensor would need to take over the ignition timing for my engine so I need one that is precise enough to do that..

I was thinking optical to measure teeth on the flywheel with one teeth grind out so it knows where the rotation starts/ends. Would this work for something like this? Rpm range would be up to 8000rpm and should work from standstill if possible for hand starting. Any help is appreciated.