i have been searching high and low and asking on the facebook rutan site as well as here for any concrete info on the rotax 912 being used in a Variez. There are lots of rumors but no one can even come up with a photo. Trying to put a rotax into a Varieze would require lots of time and money trying to figure out how to mount it , How to cool it, and the proper prop. With no flying examples it would not be easy . It would be an ideal engine probably but the examples i see of it being used as a pusher the engine is not inside a cowl . So you really dont know what will happen when you mount it backwards inside a cowl as far as CHT etc let alone how many props you would have to go through to find what works the best .