From experience I can tell you that the installation as per manufacturer is clean and the holes to the fuse are relatively small. If you try and mount the engine sideways you will have a big hole for the head and probably more than that. Remember that the engine mount is on the center of the crank case so the majority of the engine body will be sticking out the side. I do not want to discourage you from experimenting but I think the enjoyment you will gain from flying this plane will more than pay for when you weight the cleaning issues...

I am on my second 40 size Rascal, this time electric - NO COWLING HOLES... Still waiting for batteries but it should fly some time soon.