Evolution of the HEMI engine

They don't call it a legend for just any old reason. The return of Chrysler's "Hemi" engine in 2003 resurrected a blast from the past that began more than five decades ago. So named for its effective hemispherical (dome-shaped) combustion chambers, the "Hemi" was capable of ingesting huge volumes of air and fuel, essential for making high horsepower.

During the Second World War, Chrysler's 16- cylinder Hemi-headed engines were used to power fighter aircraft through the 500-mph barrier in level flight. Later, a V8 version was developed for use in passenger cars.

In 1951, Chrysler released the Saratoga Coupe with a "Fire Power" Hemi that shot to the front of the performance race. In short order, Hemi-powered vehicles were dominating the highways and races tracks.

Under the guiding hand of stock-car racing icon Richard Petty and drag-racing legend Don Garlits, respect and admiration for the Hemi vaulted to mythical proportions.

By the end of the 1960s, the Hemi eventually became an option in most popular Chrysler body styles, including the Charger, Road Runner, Barracuda and Challenger, putting out a conservative 425 horsepower from its 426-cubic-inch (seven-litre) displacement.

The Hemi ceased production in the early 1970s, a casualty of rising insurance premiums, the oil crisis and tighter emission regulations. Of all the major racing formats, only drag racing managed to maintain its use in sanctioned events.

Now, it is good-old-days nostalgia plus the skyrocketing values of original Hemi-equipped iron that keeps it from being forgotten. The Hemi's triumphant return, in a smaller and a much more modern state, is certainly reason to celebrate.

Key to the new engine's success was an aggressive marketing campaign linking the present to the past, as well as the 425-horsepower rating given to Chrysler's top-performing models, equal to the horsepower rating of the Hemi from the muscle car era. Even better is the return of the Dodge Challenger.

The nostalgia circle is complete. It's a fitting tribute to an engine that has proven to be not only unbeatable, but apparently unstoppable.