The inner tubes are insulated from each other and the 1 inch one is connected to the bolt through the bottom. The delivery tube and outer case must be isolated from the rest of the car. The deliver tube runs towards the carby or throttle body. The cell is filled with specially charged water and the timing is adjusted over a couple of days . At the end the fuel is cut off all together and the motor will be running with a advance between 25 and 80 degrees.
Castiron engines are the hardest to do.
This photo taken just a current is beig applied notice the gas bubbles being formed, a few seconds later the entire glass is filled with a white mass of bubbling foam Aluminium is the easiest to do. The exhaust is ice cold, the radiator has ice on it and it has twice the power of a petrol engine. I believe it may be worthwhile to remove the water from the block and replace it with Auto Transmission Fluid as it freezes at a much lower temperature. I would expect that the water pump vanes would need to be clipped or drilled to decrease efficiency and drag in the oil. The bolt on the bottom is connected to the chassis.