I'll bet you find you like the difference the condensors add into it!
The (continued) use of condensors at the breakerpoints in combination with a transistor ignition appears strange to me. Usually with such a module there's very little current left at the points. I was advised to disconnect my condensors when I installed my homebuilt transistor ignition.
Yes, that's what I was thinking. Why is there any need for condensers at this point.
The need for condensors in these type of Ignitions is not the "normal think" reason: it is to resolve the vagaries of a mechanical trigger driving [much] faster electronic switches. Here's what often happens: with enough miles (and neglect to the advancer) the points cam develops quite some slack between it and the middle post spindle (bearing). Then, when the points are first pried open, they tend to push the cam away from them, while the other set of points is just then trying to push the cam TOWARD the newly-opening ramp side. This can make the cam 'bounce' or jiggle a bit. With points alone, the cam is busy at that moment trying to bash open the pit that welded shut after the last spark cycle, and the slack is pushed back onto the spindle until enough ramp and force builds up to pop open the contacts (and make a tiny pit). Then you get one spark.
Enter the transistors: there is no arcing left, so the points do not weld shut: but the points cam is already worn and wiggly. So, when the cam comes to, say, the 1-4 set of points and starts to gently slide them open, the spring on the 2-3 side is still pushing the cam (and slack) toward the 1-4 side just then. This can (and blow 3000 RPM often does) cause the points to START to open, then the slack is pushed back by their spring as the 2-3 side is letting go, and the points momentarily close again. Here's the "rub": this first opening event triggers the [very] fast transistors to open and start the coil's magnetic collapse, only to close and [very] quickly snuff it out by switching the current fully back ON again until the cam slack is gone: then it finally opens 'for real' to make the spark. The problem: the coil is now caught in mid-field-collapse, so the spark is about 60% of a normal spark (or, as others know it, a "Dyna S spark...") from being OFF too short a time to recharge the field.
All of this is due to the mechanical parts, which were not designed specifically to interface tight tolerances to much faster electronic parts. So, what to do? If you leave the condensors in place, they slow down the actual "open" signal to the transistors by :
(100 ohms x 0.24uF) = 2.4 milliseconds
which is 8x as long as it takes the ramp to open the points at 2500 RPM, which is:
(5 degrees opening ramp/360 degrees) * (60 sec/min / 2500 Rev/min) = 0.3milliseconds opening event.
Thus, this condensor "smooths out" the mechanical irregularities of the cam itself by "holding the points closed" until they REALLY open. In practice, I have found that it delays the timing by about the width of the "F" mark on the advancer if you set up the timing on points, then plug in the box, and look at it again with the timing light. So, it provides a stronger spark below 3500 RPM, which can (and has, by me...) be directly measured with an oscilloscope clipped onto the sparkplug leads. It was fun to dig this out, way back in 2006 when this all started.
