This is a 1950 Ford Flathead V8 that’s been rebuilt and fitted with a set of Ardun overhead valve heads – a period-correct performance upgrade that vastly increased horsepower, making in a darling of the hot rod scene.
This engine is reportedly in fully operational condition and it’s fitted to a run stand, allowing it to be started and run normally. That said, it would look a whole lot better in the engine bay of a ’32 Ford highboy.
Ardun overhead valve heads were a period-correct performance upgrade that vastly increased horsepower, making in the darling of the hot rod scene. Image courtesy of Zora Arkus-Duntov.
History Speedrun: Ardun Heads
The Ardun overhead-valve conversion heads were among the most significant upgrades ever devised for Ford’s flathead V8. Developed in the late 1940s by brothers Zora and Yura Arkus-Duntov – Belgian-born engineers of Russian heritage based out of New York – the Ardun (a contraction of “Arkus-Duntov”) was designed to fix the flathead’s two biggest weaknesses – poor breathing and chronic overheating.
By 1947, the Duntov brothers had turned their engineering attention to Ford’s popular (but thermally challenged) V8. Their company, Ardun Mechanical Corporation, had built munitions and tooling during World War II, and after this they focused on designing automotive performance parts.
The Ford Flathead V8 was affordable and plentiful, but its side-valve design limited power and created hot spots around the exhaust ports. The Duntovs’ solution was to convert it into a hemispherical-chambered overhead-valve (OHV) engine. Each head was a complex aluminum casting with individual rocker assemblies and cross-pushrod actuation, placing the valves directly over the combustion chambers for better flow and cooler running.
The conversion kit was released in the late 1940s, not long after WWII, it included two aluminum heads, valves, springs, rocker arms, pushrods, lifters, intake and exhaust manifolds, rocker covers, and port plates. It improved airflow, cooling, and reliability while completely transforming the engine’s character. A stock Ford 239 cubic inch flathead made about 100 bhp, but with Ardun heads output rose to roughly 150 bhp in street trim and up to 175 bhp in race tune.
Compression ratios varied depending on piston design rather than the heads themselves. The setup added about 60 lbs of weight and made the engine noticeably wider, but those were small prices to pay for the performance gains on offer.
Original production of the Ardun conversion was short-lived – about 200 to 250 pair-sets were completed – but the idea never died. Image courtesy of Australian Motor Sports.
By the early 1950s, Ardun heads had become a fixture in American performance culture. Hot Rod Magazine’s 1956 feature The Ardun: What Makes It Run? detailed its intricate geometry and valvetrain design, noting both its ingenuity and its practical challenges – issues like lifter galling and gasket sealing that accompanied early castings.
When Zora Arkus-Duntov later joined General Motors, he brought with him an understanding of high-performance engine design that would influence Chevrolet’s Corvette program – in later years he would be nicknamed the “godfather of the Corvette.”
Original production of the Ardun conversion was short-lived – about 200 to 250 pair-sets were completed – but the idea never died. Interest revived in the 1960s and 1970s, and by the mid-1990s, California-based engineer Don Orosco produced 30 accurate reproductions.
Today, Don Ferguson Enterprises manufactures new Ardun heads with updated materials, improved geometry, and CNC machining. These modern versions remain popular among vintage racers, Bonneville competitors, and traditional hot rodders seeking both authenticity and performance.
The Ford Flathead V8 With Ardun Heads Shown Here
The engine you see here is a 1950 Ford Flathead V8 that has been rebuilt, and it’s been fitted with rebuilt Ardun heads. During the rebuild the engine was bored .060 over, and it was stroked, given new main bearings and rod bearings, a high volume oil pump, an electronic ignition, ARP main bearing bolts, a hew high performance cam, and a high torque starter.
The engine you see here is a 1950 Ford Flathead V8 that has been rebuilt, and it’s been fitted with rebuilt Ardun heads.
The engine is now fitted with dual 97 Stromberg carburetors, a Tremec 5-speed manual transmission with a hydraulic output shaft yoke included, and a new Radiator with an electric fan. It’s now running, and it’s fitted to an engine run stand that’s included in the sale.
It’s now due to roll across the auction block with Mecum in mid-January and you can visit the listing here if you’d like to read more or register to bid.
Images courtesy of Mecum
Articles that Ben Branch has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.
