Hello. Can someone tell me how it affects the flight of a 66" wing span, high wing .60 nitro-powered aircraft, if the engine is mounted at 45 degrees or 90 degrees.? Thanks in advance for your answer.

Provided the correct thrust angles are incorporated, no difference at all.

Many designs put the engine at 45 degrees so exhaust is pointed down. Personally, I like that.

Correct. It's all about how the plane looks and what you need to get the muffler in the right place. Inverted engines can cause some issues, but only in idling properly due the height of the carburetor in relation to the tank.

Hi!
Heard from someone many years ago that placing the engines in a boxer configuration (BMW style) eirher with the cylinders pointing out or in or to the right or left would increase vibrations. Best would be in a V -configuration , either having the cylinders pointing down or up.

I can't tell that it does. I've had several planes with sideways engines, several with straight up engines, and a couple of inverted ones. I don't see any difference in the vibrations assuming the prop is balanced.

Hello. I flew the modifiqued Das Ugly Stik
(seven difference) last week whit inclined engine at 45° and no difference. Thank for your comments. I send you a picture.