Tech info wanted; Lean Burn Dist

Crank degrees is 2x distributor degrees. The distributor moves 1 revolution for 2 crank revolutions.

This scope picture was done long ago. This is for V8 not 6. I think the bottom trace is the primary pickup, the upper is the secondary. In the lower the zero crossings are a cylinder apart or 90 crank degrees. On the right shows measured timing in ms, using the grid the placement of the upper trace can be estimated. 90* 12.2/27.8 = 39.5 degrees. I think mopar actually used it for a ~50 degree advance, and electronic time delay from there. That is similar to what I do with shutter wheels with opto or Hall and a micro. Technology has vastly improved in the 40 years after lean burn.

I get queasy looking at the waveforms, nothing I would consider using for accurate timing control. The variation in amplitude is not a good thing, nor the magnetic leakage from second pickup magnetic circuit.