distance btw the firewall and the Rotax engine attachment points
I am designing my first airplane, an LSA. My questions are what are the considerations in determining the distance btw the firewall and the Rotax engine attachment points, and how much it should be.
I plan to use composite for both the airframe and the firewall, and have not decided to use 912 or 914. I assume the 4 attachment points for Rotax 912 and 914 are the same, with a vertical distance of 270mm between upper attachment points and lower attachment points and a horizontal distance of 210mm between left attachment points and right attachment points.
I would like to have the spacing btw firewall and the attachment points as short as possible to keep the airplane compact. What are the limiting factors and possible values?
Jeffrey