Looks like a Hall-Scott engine
NASM Photo (NASM 00073665 with permission)
Photo from Canadian Aircraft since 1909 by K.M. Molson & H.A. Taylor. Although the photo caption identifies the engine as a Cutriss C-6, I think this is a Hall-Scott engine. The intakes are on the wrong side for a Curtiss C-6 or K-6.
