09/19/2026
Flatheads Forever.......
Before Zora Arkus-Duntov became the father of the Corvette, he designed hemispherical overhead-valve cylinder heads for the Ford Flathead V8. He offered them to Ford. Ford said no. So he built them himself, founded the Ardun Mechanical Corporation in New York with his brother Yura, and created one of the most significant pieces of speed equipment in American hot rod history. The name "Ardun" is a contraction of ARkus-DUNtov. About 200 to 250 pair-sets were made. Today, original Ardun heads are among the rarest and most valuable pieces of vintage performance hardware on earth.
The Ardun heads solved the Flathead's two fundamental problems: poor breathing and chronic overheating. The stock Flathead was a sidevalve design with intake and exhaust valves in the block beside the pistons. Exhaust gases had to travel through the block around the cylinders to reach the exhaust ports, creating massive heat concentration. Worse, the middle pair of exhaust ports on each bank were siamesed into a single tube, creating a thermal bottleneck that cooked the center cylinders. The Ardun conversion replaced the flat cylinder heads with cast-aluminum overhead-valve heads featuring hemispherical combustion chambers, centrally located spark plugs, and four equally spaced exhaust ports per bank (eliminating the siamesed center port). Short intake rocker arms and long exhaust rocker arms actuated the valves via pushrods from the stock Flathead camshaft. The conversion used the stock cam, the stock block, and the stock valvetrain components below the head. Installation took approximately six hours by a skilled mechanic.
Zora published an SAE paper in February 1947 claiming the conversion raised output from the stock 95 HP to 175 HP at 5,200 RPM with 225 lb-ft of torque at 2,500 RPM on a standard 239 CID Ford block at 7:1 compression. A "racing" version reportedly made 200 HP at 5,500 RPM. In the hands of Clem TeBow and Don Clark at C-T Automotive, Ardun-headed engines made 267 HP on alcohol and 303 HP on nitromethane. Their Ardun-powered 284 CID 1932 roadster averaged 162 mph at Bonneville in 1951. In 1952, the Hill and Davis "City of Burbank" streamliner set a flying-mile record of 229.77 mph with an Ardun engine. In 1953, Charlie Scott became the first person to top 200 mph in an open-wheeled car using an Ardun. Alex Xydias' legendary SO-CAL Speed Shop coupe ran Bonneville and the drags with a front-blown Ardun.
