It's not easy unless you have the machines and patience to do it, but I noticed on my motor, I could possibly externalize the camshaft shaft through the crank case, add a seal and do with whatever I want to. You'd have to drill and tap the camshaft end and screw an extended rod into it, then bore a hole through the crankcase and add your oil seal. On the external rod you could place a wheel and use an optical sensor real easy. Don't try this unless you have the equipment though.
I looked at doing the pickup on one of the valve stems, but my rocker cover is steel, so without making an aluminum or plastic one, I was hosed. The gears seem to work pretty good attached aft of the generator. This also allows you to adjust the timing real easy and it has a clear visible indication of where it's currently set.
If you are thinking about doing a completely electronic solution for timing delay, let me warn you, I have done this in the past but it's not easy. I finally ended up programming custom CLPDs to make it work. Doing this with an Arduino? Good luck. If you can do it accurately, you'll be my hero. Using one of these Cypress PSoC dev kits you can do it, but it's pretty close to rocket science to do it well. Thousands of man-hours were spent at GM, Ford, Chrysler and other automotive labs figuring this out well enough to make it reliable.
I looked at doing the pickup on one of the valve stems, but my rocker cover is steel, so without making an aluminum or plastic one, I was hosed. The gears seem to work pretty good attached aft of the generator. This also allows you to adjust the timing real easy and it has a clear visible indication of where it's currently set.
If you are thinking about doing a completely electronic solution for timing delay, let me warn you, I have done this in the past but it's not easy. I finally ended up programming custom CLPDs to make it work. Doing this with an Arduino? Good luck. If you can do it accurately, you'll be my hero. Using one of these Cypress PSoC dev kits you can do it, but it's pretty close to rocket science to do it well. Thousands of man-hours were spent at GM, Ford, Chrysler and other automotive labs figuring this out well enough to make it reliable.