The ignition system will be next on the list.
The circled part below had me stumped. Just what is it and how does it work. It has no wires connected to it and in looking at several different engine builds it is completely disconnected and sometimes with out the springs.
I found this article in Popular Science from June of 1963 by George De Angelis where he was given access by the Ford Museum to the original Quadricycle and the engine was partially dissembled.
Here are his words from the article.
My engine won't have these but instead will have a CDI module with a hall sensor and a magnet attached to the flywheel.
This is only half the story and Ford came up with a elegant solution.
One ignition coil can not have two spark plugs connected to it in series or parallel. It can not reliably direct the spark to the correct plug and since one of the plugs would be on the intake stroke that plug would have an easier path to ground and would spark there not the one on compression where it is needed.
The wood block attached to engine has a center pivot post. The output from the ignition coil is attached to this post. It has a metal arm that pivots on it and it is not insulated from the post so in effect the coil is directly attached to that arm. The arm is moved via an insulated strap that is attached to it and the rocker arm so it moves with the rocker arm. There are two metal straps attached to the board with one plug wire attached to each one. When one of the pistons is close to TDC the arm has moved so that it presses against the end of the metal strip for that cylinder. It acts as a closed switch. When the ignition module fires there is now a complete path for the spark to travel to that plug. The opposite end of this arm is not touching the other metal strip so it acts like an open switch.
When the other piston comes up on compression the same thing happen but now the switches have been reversed.
That's the next part to build.
Thanks for looking
Ray