It appears with the air scoop in front, the only way for the air to get out of the cowling is through the pipe tunnel. When I flew the Magic back in the 80's I made the hole around the header pipe as large as I could. I also enlarged the exit holes in the rear of the pipe tunnel to draw air out of the plane. The engine, header and pipe are going to get quite hot, you need to get plenty of air moving through the structure.

Frank