Hier noch ein Artikel, in dem es auch um Standläufe geht:

https://www.flyingmag.com/aircraft/pistons/piston-engines-keeping-your-cylinders-happy#page-6

Ahealthy engine requires frequent use. The general consensus is that you need to fly at least once a month. While some people believe it’s sufficient to pull the airplane out of the hangar, start it up and run it for a few minutes, this can actually be detrimental. “The engine can’t get up to temperature on the ground, and all that moisture that was created during that ground run simply stays in the engine,” Palmatier said. Lycoming recommends flying a minimum of one