The most powerful automobile engine to come out of Detroit fitted in a production car, Ford's mighty 427 "Cammer" was of course really produced for racing, but popular racing series required production cars to be fitted with the engine for homologation purposes; the maker had to document that a certain number of cars had been sold to the public fitted with the engine before it could be used.
As its name implies, this engine was derived from Ford's already famous 427 racing engine, well-known for being fitted to Shelby Cobras among many others, and successful in racing prior to Ford's competitors bringing out newer, bigger and more powerful engines. The Cammer took the 427 one step further, removing more of the hitherto fundamental limitations of the big block Ford FE engine family. The means was the employment of overhead camshafts to remove the RPM limitations inherent in a pushrod V8. The Cammer was a Single Overhead Camshaft (SOHC) design, with one chain driven camshaft per bank (two in total). A dummy camshaft still occupied the regular camshaft position, to power accessories, including the distributor, that took their power from there. The Cammer was incredibly high-revving, developing a stupendous 657 horsepower at 7500 rpm. Maximum torque was 550 lb-ft, also astounding.
On its introduction in 1965, the Cammer was fitted to a very, very small number of production cars, mostly Ford Galaxies and Ford LTDs, as well as being available over the counter as an order-able part for racers. Very few were made; possibly as few as 50 were sold to the general public. They were, really, totally unsuitable as a street engine, and it's unlikely any were bought for any purpose other than as a racecar. The 12:1 compression ratio calls for racing gasoline only, and the engine, despite its huge size and amazing statistics, doesn't feel that powerful around town; the engine really needs to be revved hard to feel that power. A regular Ford 427 or 428/429 Cobra Jet is a much better street engine.
The racing series Ford intended to take its new powerplant to was of course NASCAR, to challenge Chrysler's all-conquering Hemi. NASCAR changed its rules that year, though, and Ford's new engine was barred from competition because too few had been produced and sold to the public under the new regulations. The Hemi continued unchallenged, and Ford, disheartened, gave up; possibly in the knowledge that producing enough Cammers to qualify under the new rules would only give foolish young street racers more than enough to kill themselves with, and in the process give Ford more than enough bad publicity.
Those surviving Cammer engines mostly ended up in drag racing, powering some of the next decade's successful cars. "Sneaky" Pete Robinson was the primary user of the Cammer in Top Fuel Dragster until his death in 1971 at Pomona, California, ending the career of the Cammer at the top level of drag racing.
Some have been fitted in Shelby Cobras, more likely replicas than originals, and a few lucky individuals still own production cars fitted with America's most powerful car engine ever built.
Thanks to Transitional Man for the info about "Sneaky" Pete Robinson.