The choice of engineSince we don't need to use fossil fuel for the combustion engine, we can store the tank, refueling socket, fuel pipes, etc. in the drawer. My first idea was to install a classic Rotomax 50CC on the model (the one launched by Hobbyking and which can be found almost everywhere online but due to the fact that it was not available and that in Europe it was sold at prices according me out of the market, I surfed the web a bit and on the various specialized forums finding the solution that I considered a good compromise: a Dualsky GA6000 160Kv 28 poles (180Kv also exists) which can be powered up to 12S. The weight is 1 .2kg approximately and develops a peak power of 8.4HP at 130A. Compared to the 180Kv one, it has a lower power of approximately 9% but a maximum absorption of 7%. Various recommended propellers ranging from 22x10, 23x8, 23x10 at 24x8, 24x9, 24x10, 25x10. I had a 24x10 carbon Mejzlink at home and therefore I used this one which in the Dualsky tests on the bench at 12S develops 17kg of pull at peak power with 125A of absorption in the performance curve this engine with half the throttle delivers around 6kg of pull with just over 25° of absorption (!).