For the 1923 season, the American Automobile Association (AAA) introduced a new Grand Prix-inspired formula, limiting engine displacement to two liters (122 cubic inches). Harry A. Miller & Co. responded with what would become one of the most influential racing car designs in history: The Miller 122. Compact, exquisitely engineered, and devastatingly effective, the 122 marked the first true series-built American racing car. Each car required more than 2,000 individual components, all designed and manufactured in-house at Miller’s Los Angeles works. The result was a remarkably light, rigid, and powerful single-seater that would dominate board tracks, dirt ovals, and championship racing throughout the 1920s, setting records that, in some cases, stood for decades.

By early 1924, Tommy Milton was among the best-known drivers in American motor racing. A fearless speedway star with national renown, Milton had already etched his name into history. In April 1920, he set the American Land Speed Record at Daytona Beach. One month later, he finished 3rd at the Indianapolis 500. In 1921, he won the Indianapolis 500 outright and secured the National Driving Championship. The following season brought numerous victories on the major board tracks, including Beverly Hills Speedway, and in 1923 he captured his second Indianapolis 500 victory – this time driving a Miller 122 sponsored by Harry Stutz – becoming the first two-time winner of the great race.

Flush with success and personally involved in the technical evolution of American racing machinery, Milton approached Harry Miller with a singular purpose. He envisioned a one-off machine built expressly for speed record attempts – sleeker, more specialized, and more adaptable than the standard championship cars. As documented in Mark L. Dees’ authoritative work The Miller Dynasty, the resulting project was conceived to accept either the two-liter 122 engine or Miller’s larger three-liter 183 straight eight. Factory drawings identified the car as the “183 Convertible,” a reference to its interchangeable powerplants. While broadly following the architecture of the 122 single-seaters, the larger engine necessitated a longer and slightly taller bonnet, giving the car a distinctive and purposeful stance.

Aerodynamics were paramount. With no need for repeated braking during straight-line record attempts, conventional wheel brakes were eliminated entirely and replaced with a single driveshaft-mounted brake, removing unnecessary mass and drag from the airstream. The car’s extraordinary narrowness was further emphasized by slim wire wheels fitted with full discs on both sides. Finished in stark, functional form, the completed machine bore “Miller Special” script and racing no. 5, its appearance vividly signaling its singular mission.

Milton’s association with the 183 engine ran deep. As early as 1920, he had been instrumental in the engine’s conception, persuading Miller to pursue a straight-eight design inspired by the best elements of contemporary French Ballot and American Duesenberg engines. Barney Oldfield famously borrowed $5,000 from Henry Ford to fund the project on Milton’s behalf. With Leo Goossen’s engineering brilliance, the collaboration yielded the foundation of the Miller engine dynasty. Once refined, the 183 came into its own, dominating the 1922 season and serving as the template for every significant American racing engine that followed, including Offenhauser and its successors well into the 1970s.

Although rendered obsolete for championship racing under the 1923 two-liter formula, the 183 remained an immensely powerful and well-developed engine – ideal for outright speed. One distinctive feature of the 183 was its availability with either left- or right-side exhaust discharge. The engine selected for the Convertible featured left-side exhaust, a configuration believed to trace to one of Milton’s own Leach Specials, or possibly an engine salvaged from the ill-fated Baby Chevrolet/Durant Special wreck at Kansas City in 1922.

All standard Miller 122 single seaters featured right-side exhaust with left-hand steering. The 183 Convertible stands alone as the sole Miller of its type with left-side exhaust and right-hand steering, making it instantly recognizable. The steering gear itself was likely adapted from late-1922 Durant Specials, and the 122 engine required only modest modification to reverse the cylinder blocks for left-side exhaust routing.

On April 4, 1924, Milton’s new car was transported to Muroc Dry Lake in the Mojave Desert. With the AAA present to officiate, Milton, Miller, and their crew prepared for record attempts. At the time, Milton himself held the American Land Speed Record at 156.03 mph, while the European record stood at 133.75 mph – set by the massive 18.3-liter Sunbeam driven by Kenelm Lee Guinness. These were colossal, multi-engine or large-displacement machines.

Against this backdrop, the results were extraordinary. With the three-liter 183 installed, Milton achieved a speed of 151.26 mph – less than five mph shy of his own national record, and fully 17 mph faster than any European record. On the same day, the engines were exchanged, and with the two-liter 122 fitted, Milton recorded 141.17 mph – an astonishing performance for a car of such modest displacement.

By mid-1924, the car appears to have seen limited further use. A Los Angeles Times article published on June 13, 1924, noted it sitting idle, prompting interest from Ralph DePalma, who reportedly tested the car at Ascot and inquired about its purchase. Photographs show DePalma posed in the Miller with Hollywood starlets, though no confirmed sale occurred. Miller historian Jim O’Keefe later claimed that Norm Batten drove the car in AAA Eastern fairground races while it was still owned by Milton.

During the late 1920s, the car passed into the hands of Jimmy Gleason, who campaigned it successfully at Langhorne, Pennsylvania, and Laurel, Maryland. It is widely believed that during this period the chassis was shortened from its original 100" wheelbase to approximately 94", a practical modification for improved handling on tight dirt tracks.

Following Gleason’s stewardship, the Miller faded into obscurity until the late 1960s, when it was rediscovered by noted dealer and collector Tiny Gould of Pennsylvania, languishing in the back of a repair garage alongside another derelict racer. Though Gould initially misidentified it, he ultimately sold the car at the 1975 Pocono Speedway auction, where it was acquired by David Uihlein – founder of the Harry A. Miller Club and one of the foremost champions of American racing history.

Under Uihlein’s care, the car was correctly identified as Tommy Milton’s 183 Convertible. A proper Miller 122 engine was sourced and installed, the car was cosmetically refurbished, and later comprehensively restored. While the original right-hand steering gear had been lost and replaced with a Schroeder unit, the car was returned to active use and displayed prominently at Miller reunions, including the Milwaukee Mile.

Retained in Uihlein’s renowned collection until 2007, Milton’s Convertible was then acquired by John Price, another devoted Miller enthusiast, and has since remained a highlight within a distinguished collection of American racing icons.

Harry Miller’s legacy remains one of the great, if underappreciated, achievements in automotive history. His cars – functional sculptures of precision and beauty – rivaled anything produced worldwide. Few genuine Millers survive, and this example claims the desirable attributes of a one-off build, documented record attempts, and associations with legends including Tommy Milton, Tiny Gould, and David Uihlein. Whether preserved and enjoyed as presented or further refined using today’s depth of scholarship, the 1924 Miller 183 Convertible stands among the most compelling expressions of American racing ingenuity.

*Please note that this vehicle has been in long-term static storage and may not be currently operational. It will require mechanical attention prior to road use.