What was the valve arrangement of the Model T engine?

The Ford Model T engine used side valves, also called an L-head or flathead arrangement. Its valves sat beside the cylinders in the engine block rather than above them in the cylinder head.

The engine was a 177-cubic-inch, four-cylinder gasoline unit producing about 20 horsepower. Ford favored the layout because it was mechanically simple, compact, inexpensive to manufacture, and relatively easy to service—important qualities for a car intended for mass ownership.

The Model T’s engine and two-speed planetary transmission formed a closely integrated power unit. Its gravity-fed fuel system also reflected the car’s straightforward engineering: fuel normally flowed from a tank beneath the front seat without a fuel pump.

“Overhead valves” and “overhead cam” describe later, different valvetrain arrangements. The Model T was a flathead, although the term “flathead” can sometimes be confused with the later Ford flathead V8 introduced for the Model 18 in 1932.