The engine is a unique design. Fire departments back in the day were heavily invested in horse-drawn pumper equipment that was too cost-prohibitive to replace. So inventor J. Walter Christie devised a front-wheel-drive engine that could hitch up to the pumper wagon, simply replacing the team. Leno says it was cheaper to operate in the long run than feeding and stabling the horses, but who knows.
The further curiosity about the design of Christie's 1911 fire engine is that only the outer rim of the front wheels turn — the center is stationary. "It's fascinating to watch," Jay says. "Looks like Michael Jackson moonwalking."
Christie, by the way, was the inventor of a eponymous suspension system that allowed military tanks to move faster over rough ground, along with a convertible drive system that let them run on either wheels or tracks. (Jay incorrectly says Christie invented the tank, then peddled it to the Russians. It's true that Christie's innovations were crucial to the tanks Russia used to defeat Hitler.)
This isn't the first Christie engine Leno has crossed paths with. In an episode years ago, he was driving a Christie when it threw a piston though the side of the engine. (Leno shows the piston and bent connecting rod in this episode.) The repair took years. Meanwhile, Leno was intrigued by the machine.
Back in the 1970s, Los Angeles had sold the engine in this episode to the fire department in Wayne, N.J., as an antique for use in parades, but it broke down a few years later. The department wanted to put it in a museum, but Jay called, whisked it away and restored it, and plans on donating it to the Los Angeles Fire Department Museum.
Jay goes on to show off the 20-liter, four-cylinder T-head engine. "Each piston's about a 327 Chevy engine," he says.
It's a sweet episode, and a fascinating engine to listen to. And as always, it's wild to watch Jay drive such a thing in L.A. traffic.