Speedway Motors: Vintage Overhead Valve Conversions for the Flathead

Our friends at Speedway Motors‘ Museum of American Speed have done a great job at documenting all forms of racing, paying close attention to circle track racing specifically. Speedway Motors founder, the late “Speedy” Bill Smith, was personally invested in dirt circle track racing. 

Smith was considered a “career-builder” by many in the sprint car circles. Being selected to drive the Speedway Motors house car could make or break a driver’s career. Most of the Speedway Motors’ Sprint Car drivers ended up in the Sprint Car Hall of Fame.

That being said, it doesn’t surprise us that Smith’s Museum of American Speed has many examples of the Flathead Ford engines with Ardun heads. Few people equate Ardun head Fords with dirt track racing, but there were many cases where these engines showed up on the dirt in the “Champ” cars, Sprint Cars, and even in the Mighty Midget race cars.

An Ardun-powered open-wheel car. Photo from www.jalopyjournal.com.

Ardun Heads

Zora Arkus-Duntov (Ar-Dun), would later become known as the “Father of the Corvette,” originally began business with his brother Yura. They operated Ardun Mechanical Corporation in New York. In 1947, they were hired by Ford to improve the power of their truck engines.

The brothers worked with staff engineer George Kudasch and came up with an overhead-valve cylinder head with hemispherical combustion chambers that improved the breathing and combustion efficiency of the flathead Ford engines.

Being racers, they took their work to other flatheads Ford engines, including the popular dirt track V8-60 engines used in Midget auto racing. The Ford Motor Company decided they needed larger displacement engines, but the cylinder head conversion kits made by Ardun Mechanical Corporation began to filter into the hands of racers.

The Museum of American Speed Pays Tribute To The Ardun Heads

Recently the Museum of American Speed paid deep respect to the legendary Ardun conversions with an article by Joe McCollough on the Speedway Motors’ publication The Toolbox, which highlights how-to and historic work. As purveyors of dirt track and historical race engine information, we wanted to repost McCollough’s article here and direct our readers to The Toolbox where more of these type articles are published.

Republished article:

Vintage Overhead Valve Conversions for the Ford Flathead by Joe McCollough

Hot Rod Ingenuity

The early history of hot rodding was built on the back of the Ford Flathead V8. The formula was simple; strip an early Ford down to its essentials, lower it a little, and swap the banger engine for a more powerful flathead V8. But then as now, in the quest for speed and power, more is never enough. It wasn’t long before the limitations of Ford’s valve-in-block design became apparent. This was made even more apparent when the hot overheads from Detroit started to make their way between the frame rails of hot rods and race cars at the lakes. A stock Hemi, Olds, or Cad overhead was capable of putting the hurt to a seriously built flathead.

But hot rodders are a resourceful bunch, and even before the factory overheads became a threat, they were repurposing and fabricating overhead conversions of their own to be fitted to the beloved flathead. The result: big power (for the time) and new records at the lakes. But there was a second, unintended consequence to these feats of engineering: they were absolutely beautiful. Check out the gallery below for evidence of this.

Not only does the Ardun have solid performance chops, but they are also beautiful engines that look like jewelry when places between the rails of a hot rod or Bonneville streamliner.


The Ardun is the best known of all the early overhead conversions. Developed by Zora Arkus-Duntov and his brother Yuri in the late ’40s. Zora would go on to great success at GM as the “Father of the Corvette” and author of the now legendary memo encouraging GM to do more to appeal to the burgeoning hot rod crazy “youth” market. But before he rose to fame, he created these heads to improve upon the flathead’s relatively low power and tendency to overheat. They featured large ports and hemispherical combustion chambers (which reportedly had more than a little to do with the development of the Chrysler Hemi) and claimed 175 horsepower on a stock Mercury flathead. But they really came into their own as record-setting race heads in the hands of Clem TeBow and Don Clark at C-T Automotive. After serious work improving the valvetrain, they made 267 horsepower on alcohol and 303 horsepower on nitro. From there, the Ardun became a force to be reckoned with at Bonneville and the drags.

Cotton Werksman’s famous T ran an Ardun long before repops were available. In addition to Tom Senter’s “Ardun White Papers”, Werksman’s T did a lot to remind the hot rodding world of the Ardun legend.

The Ardun remains famous today thanks to the efforts of Clark and TeBow as well as several hot rodders that have continued to develop them over the past 70 years. Sidney Allard used them in his famous J2 sports cars. Tom Senter wrote a series of “Ardun White Papers” that appeared in Rod & Custom in the early ’70s. The famous Ferguson racing family would continue to develop them to set Bonneville records. Ultimately, Don Ferguson Jr. would take over Don Orosco’s effort to reproduce them, making it possible for hot rodders to purchase a brand new set of Ardun heads.

Ardun’s are rare, but the smaller versions made for the V8-60 are super rare.



Lee’s Speed Shop in Oakland, CA was one of the first speed shops in the country, having been founded by Lee Chapel in the early ’30s. Chapel created the Tornado OHV Conversion seen here. This engine also features a Lee Chapel custom made intake manifold.


This engine ran at the August 1950 Bonneville Speed meet in a streamliner sponsored by Lee’s Speed shop. It reached 175 mph and set a record for OHV V-8 engines, but was not the fastest on the flats. The Tornado ran at Bonneville with a 180-degree crankshaft also.


These heads were built by Rudy Moller and Kenny Adams and used a hemispherical combustion chamber that was similar to the Ardun but used some complex rocker geometry to make it happen. In spite of the Rube Goldberg nature of this setup, they were very successful, especially in the hands of flathead masters Clem TeBow and Don Clark at C-T Automotive (see above for more on their work with the Ardun).



They built the very engine you see here using these heads and a sophisticated slide-valve injector to run Bonneville. On a load of nitro, this engine made 320 horsepower and ran 229.77 mph in the Hill-Davis City of Burbank streamliner in 1952, breaking a record held since the ’30s by Germany’s Auto Union.



This wild DOHC design was developed by Joe Davies and a pair of these heads appeared at Indy in the Bob Estes Special in ’51, having been run the previous year with an Ardun flathead. Later versions were driven by a belt, but those pictured here are the earlier shaft drive versions.



These cast-iron heads were built by “Colonel” Alexander before WWII. These heads were of an “F-head” design, which relied on the stock flathead intake passages and moved only the exhaust valves and ports out of the block. This helped to rectify the age-old flathead heating issue caused by the exhaust passages winding through the block and its water passages but didn’t do a whole lot to help actual airflow.



These heads were developed for the early 21 stud blocks and were surprisingly sophisticated, featuring four intake and four exhaust ports (unlike other contemporary designs like the Alexander which forced multiple cylinders to share an exhaust port). Early versions reportedly had the intake coming in on the outside of the head. Later versions (like those featured here) used adapters to allow for a stock-style flathead intake manifold.



These imposing looking heads were reportedly built in the ’50s for a Pike’s Peak entry and resemble a big cast-iron version of the Ardun head. Only 3-4 sets are known to exist.


For More Information

If you want more information on the Speedway Motors’ Museum of American Speed, visit them online www.museumofamericanspeed.com. If you want more information about The Tool Box or Speedway Motors, visit them online www.speedwaymotors.com.

Article Sources

About the author

Bobby Kimbrough

Bobby grew up in the heart of Illinois, becoming an avid dirt track race fan which has developed into a life long passion. Taking a break from the Midwest dirt tracks to fight evil doers in the world, he completed a full 21 year career in the Marine Corps.
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