Wires from the silicon chip connected each electrode to a plug sitting on top of his head, and a cable attached to this plug transferred data from the wires to a computer for analysis.

The most common "hole" in a cylinder occurs where the top of the cylinder (holding the valves and spark plug and also known as the cylinder head) attaches to the cylinder itself.

The spark plug must form a good seal inside the cylinder head to avoid leakage of without the high-tension current shorting-out.