Description
The Ford Model T Rajo Special was one of the most famous and desirable speed modifications of the Model T era, created by the Rajo Motor Company, founded by Joe Jagersberger in Racine, Wisconsin. While the Model T was a sturdy and affordable car, its modest 20-horsepower four-cylinder engine left little excitement for drivers seeking speed. Jagersberger, an accomplished racer and engineer, developed a series of aftermarket cylinder heads and kits that transformed the humble T into a true performance machine. These conversions became known collectively as the Rajo Specials.
At the heart of the Rajo Special was the replacement of the stock Model T’s L-head (flathead) cylinder head with Jagersberger’s overhead-valve (OHV) designs. The most famous of these were the Rajo Model 30, Model 31, and later multi-valve designs, which dramatically improved airflow and combustion efficiency. Depending on the head and setup, power could leap from the stock 20 horsepower to 40, 60, or even more than 100 horsepower in racing applications. This turned the Model T into a competitive car for dirt-track racing, hill climbs, and amateur motorsport across America in the 1920s.
The cars themselves were often stripped-down Model Ts fitted with lightweight speedster bodies—sometimes homemade, sometimes supplied by coachbuilders—that emphasized performance over comfort. Wide-track axles, lowered suspension, wire wheels, and improved brakes were often added to match the newfound power of the Rajo-equipped engine. The result was a nimble, fast, and affordable racer that ordinary enthusiasts could build themselves.
Rajo Specials quickly became a fixture in grassroots racing. Across America, young drivers modified their Ts with Rajo heads and took to local tracks, competing against Frontenac-equipped Fords (the famous “Fronty Fords” linked to the Chevrolet brothers) and other aftermarket conversions. The Rajo brand earned a reputation for quality and speed, and its products were among the most popular performance upgrades of the Model T era.
Beyond racing, the Rajo heads also found use among farmers and rural drivers who wanted extra pulling power or speed for everyday use. The durability of the designs meant they could handle hard work as well as thrills.
Today, surviving Ford Model T Rajo Specials are highly prized by collectors and vintage racing enthusiasts. Their combination of historical significance, mechanical ingenuity, and racing pedigree makes them some of the most exciting Model T-based machines. They represent the spirit of early American hot-rodding—taking a mass-market car and transforming it into something thrilling, competitive, and deeply personal. In many ways, the Rajo Specials foreshadowed the hot rod culture that would blossom in later decades, proving just how adaptable and influential the Model T truly was.