I'm on the fence here. I say maybe it's somehow possible that these could be functional or somehow made functional if they are not. However, I do see some flaws that seem to support the contrary. In at least one of the shots, the angle at which the engines are mounted seem to be blocking the pedals. I don't see a way they could be mounted and not block the pedals. Even if the pedals were not blocked from making a full rotation, how do you get you legs around 6 (7?) engines? Therefore, pedal starting would seem to be an impossibility. Also, no centrifugal clutches that I noticed. So how do you start them? At the top of a hill? How many clutch levers? One cable for all engines? Won't work. And even if they do start and run, I can't see where they would be legal in any state, and they are not practical either. I lean more towards display/conversation piece, because even if somehow functional, they are not practical in the loosest sense of the word.