Prototype parts were 3D printed using the SLA procrss where a laser solidifies a resin. This process was needed for the required dimensional accuracy. The prototype parts were then assembled, along with 123 electronics, into an original distributor body and tested on Jacques distributor test machine. All worked as it should.
The next step was to make a small run of production parts. The new shaft and magnet plate are shown below. Disassembly of the original distributor is the first step. Assembly of the retrofit kit is then fairly straightforward as shown in the photos below. As of this morning I have proof of concept . I set the 123 retrofit distributor up last night and then started the car this morning. Everything worked perfectly.
The motor I am testing on is a 587/1 rebuilt to 904 specs. Ignition system prior to the 123 retrofit consisted of 2 original distributors with mechanical advance and Pertronix 1 in place of points. The distributors are run in a master/slave arrangement with two Winterburn CD boxes. The motor ran well with this system and never fouls plugs.
After calibrating the 123 electronics as they recommend I started the car and it started easily. Timing was about 3 to 4 degrees out but quickly fixed with a timing light.
- There is far less jitter in the timing mark - rock steady. This is compared to a stock mechanical advance distributor with a Pertronix 1 with the mechanical advance functioning properly.
- Upon startup it idled steady at 800 rpm. With the stock distributor it would idle at 600 until warm. When warm it idled at 1000 and came down to that rpm smoothly. No slowly wandering down.
- The engine seemed more responsive and seemed to have more torque at low rpm’s - probably due to the stock distributor advance curve not following the stock curve - ie, not enough advance early enough.
All in all I am very happy. Now I need to put a few more miles on the system to make sure it is reliable before offering retrofit kits for sale.
One thing I would recommend potential buyers consider is to retrofit only 1 distributor and use it in combination with the Winterburn twin CD master/slave set up. That way only 1 distributor needs conversion, there is redundancy in being able to quickly rewire to reverse the master/slave relationship and the system eliminates plug fouling and other problems.
I mounted my CD boxes inside the car on the rear firewall which gives me very short wire runs. But this is not practical for most people. And there is not a lot of room in the engine compartment. I corresponded with Fred Winterburn and he confirmed that placing the CD boxes in the passenger footwell would work fine as long as 2 of the wires were separated for the run back to the engine compartment.
If anyone is interested in future purchase of a retrofit kit please let me know offline and I will keep you posted. Please feel free to email me questions.