Is it possible to use an existing gear box with a long prop extension? In other words let's say you have a 2 cylinder standard Rotax meaning a known engine with a known gear box. Is adding a prop extension in bearings and a coupler an entire new design project for the engine and gear box? I know that adding a long shaft in bearings is another design story but assuming you isolate the engine from radial and axial loads from the added prop shaft assembly would you need to modify the engine of gear box for the added system. Another way to do that would be to remote the gear box and put the extension shaft between the motor and the gear box. The reason I am asking is for smooth pusher cowling reasons and for possibly adjusting the CG of pusher designs without screwing up the airflow or layout. It gives you a degree of freedom in the engine installation restrictions of the engine assembly by itself.
