One of the biggest problems with the conversion in the beginning was the fact that in the Renault 4CV the flywheel and the clutch are buried within the engine, not in a clutch bell housing as in most other cars.
Here’s a video where I explain what the problem is:
To better understand the problem, here’s a closeup picture of the gearbox, on the side where usually a clutch bell housing would sit. But in the picture you can clearly see that the input shaft of the gearbox is protruding from a flat surface:
So we had to build a custom clutch bell housing, out of two adapter plates (once to the motor and once to the gearbox), and a cylindrical middle part which is held together by long screws with bolts. This is a solution I designed myself, first on paper, and then on CAD.
The parts were machined out of aluminium.
Here’s the result:
