The fuel air mixture in the combustion chamber needs to be ignited at the correct moment to ensure efficient combustion and power generation by the engine. This is the job of the ignition system, be that the old fashion magneto of the good old days or a modern fully electronic microprocessor controlled FADEC system. For safety reasons the ignition system does not rely on the the aircraft electrical system and is dual and each system operates one of the two spark plugs in each cylinder.
The document below describes the drop in electronic ignition from E-MAG Ignitions TX.
Installation and Operation Guide (27 pages) for models E and P-mag.
Excerpt from the document:
Your ignition is designed to make installation as straightforward and as simple as possible. To further assist you, this manual will supplement the installation steps with a variety of comments and tips that are shown in blue. Note: The term “E-MAG” shall apply to both E model and P model ignitions, unless specifically stated otherwise. P models have a built-in backup alternator and E models do not.
Certain segments of this manual are applicable to the Continental O-200 or the Lycoming ignitions only. Such segments will be identified with the bracketed notation “[Continental]” or “[Lycoming]” as appropriate. The “Lycoming” reference applies to Lycoming as well as other “Lycoming-like” engines.
To continue reading see the pdf below: