While talking to a friend about REP, he asked me about how the engine temperature and cooling would be modelled. I replied that the engine management will track the engine temperatures and simulate their impact on the engine behavior (and failures). This will make the pilot motivated to take care of his engine.
Eventually, his point was about how the shock cooling is simulated in REP.
There are two theories about engine cooling. Someone says that the shock cooling actually does not exists. Someone else says that it’s an important factor to keep in mind when it comes down to correct engine management.
Let’s start with a number: 30.
30°F/min is more or less the temperature difference at wich, in theory, a cylinder should start cracking. So, if you follow the first theory, you must be very careful when flying because that temperature ratio is not that hard to reach sometimes. But what about the engine shut down?
When you shut down the engine at the end of each flight, for few seconds you get a much higher ratio than that but no cylinder cracks.
So which theory is right? You can find a very interesting article about this topic on AVweb.
That said, REP will work in between the two theories as I think it better fits my own real flight experience.
You will mainly have to follow the rule that says to keep the needles in the green arc. So, for example, after starting up your engine, do not boost up your RPM if the Oil Temperature, the Oil Pressure or the CHT are under the green arc.
With a modern Continental or Lycoming engine, if you fly with this rule in mind you will hardly encounter a problem when flying.
If you won’t follow this rule, your flight would end up before takeoff as a failure would be very likely to occur.
The engine temperature affects the startup behavior too. For example, a cool engine will require some priming before startup while a warm engine will be more prone to be flooded by fuel.
That’s it! The main mission of REP, apart having fun, is learning more about our planes, right?