I just wanna try it, but of course I have a little calculation too.
.30 engine max rpm is around 22000, with standart gear ratio I find the max rotor speed is around 2300rpm.
.50 engine max rpm is around 20000, if I still use standart gear ratio then I find that max rotor speed is only around 2000. So to maintain the max rotor speed at around 2300, I must use the 1:8.5 gear ratio. The tremendous torque of 50 engine is a bonus
In my humble oppinion.....
I used header thank, but the fly time is only slightly down

Albertus Herinanto