Thanks Guys for all your previous respones .
I have a question about the engine's installation angle.
i have install my engine on the new funtanas 40 on it's side as the manual says but while picking the fuselage up gently to turn it around i found a very noticeable tendency to roll over to the heavy side.

doesn't installing the engine that way causes a bad lateral balance ?
won't it be better to install it upside down especially on those 3d models which flies slower and requires an exact later balance ?