Pretty easily actually.

Tom had the cowl designed so it drops down below the bottom of the fuselage a little bit. It remains open at that point. It's design will create a nice low pressue zone that will assist drawing the heat from both the engine compartment and the header dump openings. The picture gives the general idea about how the cowl fits and remains open.

I added the louvered vent on mine, I'm using mufflers and wanted more exit area and won't have the benefit of the large cannister exit openings.