Engine theory
When I did my exams x years ago I questioned what good it was learning all about two and four stroke engines and having to take an exam about same when the opportunity to get out and tinker with them while actually flying was a bit limited.
The general reply was that you had to understand how the donkey works in case you needed to diagnose a problem when flying etc.
When converting to injection, diesel and jet engines a 'type' approval must obviously be obtained to fly these but, as I understand it, no theoretical examination on the workings of these is mandated.
Does the importance of understanding how an engine work disappear when a different type of motor is substituted?