Dodge Man

The Chevrolet D sold from 1917 to 1918 had their first production V8 engine. I've never knowingly seen one of these vehicles/engines in anything but a photograph. I suspect the prototype engine for this production run should be considered the first V8 but since the second V8 production run wasn't until 1955 there may not have been a prototype engine.

Here's some details on that engine...

http://jalopnik.com/5086646/engine-of-the-day-the-very-first-chevrolet-v8