The bluetooth elm327 readers are like 10 bucks and can connect to multiple applications on the phone or even a computer.
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Back when we were experimenting with the Lister clone at APL, we had an adjustable timing device. It was electronic with a simple potentiometer control with some sort of arduino circuitry. It started out working great. Simply turn a knob to change the timing. Then it seemed to drift - needing constant advancing of the potentiometer. I was told once by Mike Anthony that it needed 2 magnets and 2 pickup’s. One magnet & pickup for base signal and the other pair for the reference for the advance/retard. At the time we were simply taping a small neodymium magnet to one of the flywheels as the trigger for the hall effect sensor. It was really nice to simply move the magnet to get the timing in the desired range of the potentiometer control. Then just turn the knob to get the timing set for optimum power.
To date I’ve not been able to find out more about the circuit. I’m not really sure why.
I have a thesis a gent wrote on converting a Corvair auto engine for aviation use. He incorporated 2 spark plugs to each cylinder by making a Y shaped adapter that was affixed to the cylinders in place of a spark plug. The screwed 2 spark plugs into the Y adapter. This concept works but unfortunately has some undesirable effects. One is that it increases combustion chamber volume - thus lowering compression. Another issue is that it acts as a precombustion chamber that effectively retards timing. There is a slight increase in thermodynamic losses. The real advantage lies in how it allows 2 totally separate ignition systems without modifying the engine cylinder heads - aside from possibly milling the head(s) to compensate for compression lost using the Y adapter.
I had a multi cylinder Johnson outboard boat engine that had a belt driven magneto. I’d saved it from the scrap yard as a possible means of providing an independent ignition source or at least as a reference concept. I lost it in the fire. I do not think it had an impulse coupling which would have improved low rpm starting and retarded timing for starting. I figured that the belt sprocket could possibly be fitted to an engine’s harmonic balancer.
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Somehow a handy programmer might tune according O2 sensor and Knock sensor to adjust the timing.
I had on a smal motorbike , 125cc Honda, the injection mapped according the O2 sensor and the timing according knock sensor…
been doing similar with the tata pickup ( ran on CNG and or Charcoal gas )
Trying to implement on each engine i put gas in … 
i have even a set for converting from carb to injection, free programmable…
Some things might be expensive to do, but could or can be done…
I am always on the look for cheap versions, most of time not as succesfull as i would like…
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The circuit that we had at APL was a rather simple appearing one that fit in a plastic case. It apparently appeared too simple as it was mounted before I got there with a screw through what appeared to be an unused part of the circuit board. Unfortunately when they drilled the hole for the mounting screw it cut a trace on the underside of the board. It used a coil on spark plug type ignition coil.
We were driving a belt driven alternator off one of the open flywheels of an Indian clone of a Lister 6/1. Given the low 650 rpm operation it would have been rather easy to advance the timing so far as to effect detonation - if the wood gas were prone to detonate. I don’t think we ever got the engine to detonate. Performance would have been severely compromised by the time timing advanced to a detonation point.
The alternator that was used was capable of absorbing all the power that the engine could produce. We had a number of electric heaters and fans that we used to create a much of a load as the engine was capable of driving. Thus we could adjust timing and air/fuel ratio for best operation.
Ken Boak had hoped to test what changing compression might do to effect changes in power/fuel economy. I made a number of spacers for the change over plug that would allow this. I do not think that he was able to continue the testing.
Ken has his own web site and more. I just found a video from 17 years ago that I had not seen. One of his sites was powercubes.com For some reason it is not functional for me today.
Here is some of the Listeroid at APL. https://www.youtube.com/playlist?list=UUflU33iK5PXwpCJ7nje096g
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It looks like @spaco did video’s on this.
with code here and I don’t know if that is his final version or not. He probably should have it on a github page. (it is a version control system where you can update the code, or revert the code). In a different video, he has the wiring.
https://spaco.org/Computing/CodeForIgnitionControllerJan232016.txt
I think in this video, he figured out the ‘dwell time’ which is the time it takes for the coil to energize. This guy does an okay job of explaining it, and uses both 555 and an arduino to test coil packs.
With the cheap hall effect sensor, they run into hysteresis/bouncing and skipping issues. which IIRC is the sensor they were using at APL because they are cheap.
As far as the wiring, you are replacing the points with the IGBT, The points are just a mechanical switch, the igbt is a solid state switch, or alternatively, they could have driven it off say a battery.
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One thing about mechanical ignition points in coil ignition system . . .
The points will boost the primary circuit voltage.
Rapid gating on/off tends to not. Why the need for capacitnece storage (charging) then release. Lengthen out the spark duration.
S.U.
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It is called transient voltage.
The capacitor is on the primary side. It would assist in loading up the primary, which I can only see it being useful at higher speeds to make sure the primary is full. One of it’s main purposes is to prevent arcing in the points, which of course would destroy them.
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Use an oscilloscope trace.
Use no capacitor.
DO use a large deep battery source as your direct current voltage.
Get the current circuit flowing through a load . . .
Then slowly open your contact ‘circuit interrupter’ points.
The flowing current will want to keep flowing . . .
the voltage will rise up to 10X the supply voltage to try and continue that flow. Metals will arc and vaporize. Bite you hard if you were bare-handing becoming part of that forced pathways.
This old old stuff discovered from back in the long-lines telegraphs 1800’s. Then used forwards to the early spark-gap wireless transmitters.
Yeah. A capacitor is added to absorb this voltage spike, temperarily storing the energy wave. The wave peak and declines, the charged capacitor then discharges back into the open leg of the circuit. The energy decaying in deminshing voltage waves.
CDI is different. The larger capacitor is charged. Then gate isolated for a timed intended energy boost kick discharge into the primary side system. Giving 100’sX voltage boost ups from battery input voltage.
20th century Auto Ignitions 101. 1900’s -1999.
S.U.
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I’ve been looking at CDIs for chargas’d points engines. It would allow for easier timing advance, spark adjustments, dual sparking and other types of variation.
For small engines, coil on flywheel is really simple and simple is good. A CDI allows for additional adjustments for a little more complexity, and the CDIs are pretty cheap. You do need a voltage source… easy if you have electric start but not easy on like a lawn mower.
It’s not a common situation but if you swapped out the existing magnetic flywheel on an engine for say, a heavy belt pulley, you’d lose ignition from the points/coil and a CDI would be needed. Direct coupling is standard on generators but for chargasing you might run the engine at lower RPM and use belts to get the frequency back up for the genhead. Again… not a common case but I’d offer it up.
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Good job at finding at least something about an arduino ignition. I can’t say it is the same as what we used. I remember the name Pete Santis from years gone by but can’t place him. I think it was Michael Shilo who repaired the damaged arduino circuit board. The hall effect sensor was small. If I recall correctly it was simply a T03 cased component.
We got so frustrated with ignition issues when time was of the essence that we simply pulled the MSD ignition system off of a high performance engine that had been saved prior to burning the artwork it had been part of. Had there been a scrap yard near by, we would have dragged an old lawnmower in to reuse the magneto off from it. Unfortunately - Berkeley is not a place that has scrap yards or much in the way of industry.
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