If the B8 is the engine used on his record setting motorcycle then this engine in the photo appears to be very different from the B8.
The engine shown appears to be water cooled, his bike engines were air cooled with deep fins on the heads. This also appears to possibly be two V-4 engines mated together by the increased spacing between the middle cylinders, Curtiss engines were consistent spacing between all the cylinders on the banks.
I'm not sure what this engine is, but it may not be a Curtiss.