Quote Originally Posted by bruce.desertrat View Post
This is just an artifact of the photography. A photo of it parked clearly shows that that is just a shroud around the cylinders of the radial engine https://en.wikipedia.org/wiki/Abrams...140188595).jpg
Terrific article, Bruce, amplifies this post. Shrouded the cylinders probably aided cooling, many (most) have airfoil cross sections, IIRC early biplanes so-equipped.