Ardun hemi heads for the Ford flathead V8 have become legendary. They are very rare, and equally expensive. During the early-mid 50s, when Detroit’s new crop of ohv V8s were just becoming more available, a set of Ardun heads was the way to stay competitive.
The Ardun heads’ origin myth is not perfectly and consistently documented in every detail, but one can piece together enough elements to create a pretty clear picture. One thing is undisputed: they were originally designed to give Ford’s flathead V8 truck engines a significant boost in power, supposedly for an export order of garbage trucks being sent to Great Britain. That part seems a bit odd, but there’s some references to that. In any case, we do know that Ford passed on them (serious reliability concerns) and solved their truck power deficit by making the larger 336 c.i. Lincoln flahead V8 available in their trucks for 1949. The Duntov brothers then started to target the hot rod market.
The reference to “aircraft power” is because almost all aviation engines back then used hemi heads to optimize power output. But then there were of course some American cars that used them too, like the Duesenberg and other high performance models and racers. There had been hemi heads available for the Model T for some years.
Here’s a NYT article from August 18, 1947 about the near-completion of the Ardun heads. What’s not disputed is that recent Russian emigre George Kurdasch did the actual drafting of the heads.
This snippet is from the book “Ford Total Performance” by Martin L. Schorr. I find it somewhat questionable, for a couple of reasons: British trucks (and all over the continent) back then were generally of very modest power; less than even in the US. And it mentions that these were for London, and issues with climbing hills. There are essentially no hills in London. I find it quite unlikely that London would be importing garbage trucks from the US in the first place right after the war, when hard currency for imports was a serious problem. And if so, power seems unlikely to have been a big concern.
But it makes for a good story, although there’s absolutely no reference to it in the NYT article. And it’s certainly quite possible that one or more Ardun equipped engines found their way into trucks there, as the actual building of the Ardun heads was contracted to a firm in England.
If I had to guess, the Duntovs created the hemi heads on speculation, hoping to interest Ford generally, or possibly as a re-power alternative to existing trucks, as gas engines in trucks back then had a rather short service life and replacing them after some 30-50k hard miles was just par for the course.
Another reason given for Ford’s supposed cold shoulder was that the big and wide Ardun heads would never have fit into the rather slim engine compartments of their passenger cars and light trucks.
In any case, the early Ardun heads were quite problematic. D. Randy Riggs, in an Automobile Quarterly article on Ardun wrote: “Its cast-steel pushrods weighed the same as a connecting rod, and valve seats came loose from expansion differences of the aluminum and bronze materials. The stock Ardun valves were too heavy. Exhaust manifolds were constricted and head gaskets were a common failure. The coke bottle shaped lifters were originally made from Buick components and had a tendency to gall. Valve springs were inadequate. The two intake manifolds had no balance tube between them and were poorly designed. The spark plug tubes were a menace and the stock Ford ignition was not up to the task.”
Ardun also created a version for the smaller Ford V8-60, and these were targeted to midgets, sports cars and such from the get-go.
These were eventually reverse-engineered (copied) for the Brazilian Simca Chambord, where it was made until about 1968 there, when it was finally replaced by the Chrysler 318 V8.