If you want to see something neat, Google "1937 Ford V-8 tractor". I saw this many years ago at the Portland, Indiana show, and it sounded soooo sweet... There is a Youtube video of it running. If you search image's, there are several pics of it with the side panels up, showing the engine.
A one of a kind, built by Henry Ford. It was in the Henry Ford museum, but they sold it. Never figured out why they would sell a one of a kind item like that...