The History of the Iconic HEMI: From Modern Workhorse to the Epic Hellcat and Demon

In the first part dedicated to the history of the HEMI we covered the origins of the first generation, how it evolved, and how it rose from the ashes to become one of the most spectacular V8s of the 1960s. In this article, we’ll take a look at the modern iterations that started life as workhorses, then morphed into insanely powerful Hellcats and Demons.
Dodge Challenger Demon's HEMI 21 photos
Photo: Stellantis North America
2002 Dodge Ram 1500 Sport Quad Cab2005 Chrysler 300C2005 Chrysler 300C's 5.7-liter HEMI2006 Dodge Charger SRT85.7-liter HEMI in Dodge Charger R/T Daytona2011 Dodge Challenger SRT8 392392 HEMI2018 Jeep Grand Cherokee TrackhawkHEMI Hellcat2018 Dodge Challenger SRT Demon2018 Dodge Challenger SRT Demon2018 Dodge Challenger SRT Demon2020 Dodge Charger SRT Hellcat Widebody Daytona 50th Anniversary2020 Dodge Challenger SRT Super Stock2021 Dodge Durango SRT 3925.7-liter HEMI6.1-liter HEMI392 HEMIHemi HellcatHellephant Crate Engine
By the mid-1970s, the famous 426 was history and so were the first-generation Dodge Challenger or the Plymouth Barracuda. Although the Challenger returned in 1978, it was a shadow of its former self, just like its Charger sibling.

HEMI fans would have to wait almost three decades to witness the second comeback of their beloved engine, as Dodge introduced the third, current, and probably final generation to the 2003 Ram pickup truck model range.

The combustion chambers are no longer truly hemispherical, but flatter and more complex. The modern HEMI uses a coil-on-plug, distributor-less ignition system, and two spark plugs per cylinder to attain shorter flame travel, a design that leads to far more consistent combustion and reduced emissions.

5\.7\-liter HEMI
Photo: Stellantis North America
Codenamed Eagle, the first modern version built since 2003 displaces 5.7 liters (345 ci.). Initially, a workhorse available only in trucks and SUVs, it delivered 345 hp in Ram pickups, and 335 hp in the Jeep Grand Cherokee, Dodge Durango, or Chrysler Aspen. Passenger cars got their first taste of the modern HEMI starting with the 2005 model year when the LX platform came out.

The 5.7-liter was heavily revised in 2009 when it gained a host of upgrades, including a new block, improved crankshaft, cylinder heads, and valve-spring designs. However, the biggest changes were the implementation of Variable Camshaft Timing (VCT) and the multi-displacement system (MDS), two advanced technologies that substantially improved the engine’s efficiency. Today, it makes around 370 hp in non-hybrid models, and close to 400 hp in those equipped with the eTorque mild-hybrid system.

In 2005, Chrysler’s Street and Racing Technology (SRT) division revealed the first modern, high-performance HEMI. A 6.1-liter (372 ci.), it featured a beefier, orange-painted block, a forged crankshaft, lighter pistons, strengthened conrods, and an unmistakable barrel-shaped aluminum intake manifold. Used in all the corporation’s performance vehicles built from 2006 to 2010, it could produce between 420 and 425 hp

392 HEMI
Photo: Stellantis North America
The 6.1-liter was discontinued starting with the 2011 model year when a larger, 392-ci. (6.4-liter) took its place. A tribute to the original 392 but mechanically unrelated, it was rated at 470 hp until 2015 when it got a few refinements that bumped the output to 485 hp. It is still in use today, and it’s also available as a crate engine.

In 2015, sixty years after the 300-hp FirePower shook the U.S. auto industry to its core, a new monstrous high-performance powerplant was released by the wizards at SRT, sending rival manufacturers into a frenzy. Nicknamed Hellcat, the supercharged 6.2-liter (378 ci) HEMI could spit out over 700 hp.

Just when everyone was getting used to Hellcats prowling the streets, SRT delivered a knock-out blow with the 808-hp Challenger SRT Demon. Available only for the 2018 model year in a limited run of 3,300 units, it could even make 840 hp when equipped with the $1 Demon crate package and fed 100-plus-octane fuel. This was made possible by comprehensively modifying the initial Hellcat design. The block and main caps were reinforced, a bigger 2.7-liter supercharger was added, while the cooling and lubrication systems were upgraded to cope with the insane output.

2018 Dodge Challenger SRT Demon
Photo: Stellantis North America
The engine was just too good to be a one-year wonder, so it was succeeded by the Hellcat Redeye in 2019. Still in production today, this variant shares several components with the Demon, such as the block or IHI-built, 2.7-liter, twin-screw supercharger.

In 2020, Dodge introduced the drag strip-oriented, yet street-legal Super Stock package which comes with an 807-hp Hellcat that can transform the Challenger SRT into the quickest muscle car you can currently buy from a dealership.

Apart from the Demon, Redeye, or Super Stock Hellcat versions, the most badass modern HEMI in existence is the 7.0-liter (426-ci), all-aluminum, 1,000-hp monster called Hellephant. It was unveiled at the SEMA show in 2018, and Mopar made it available to the general public a year later in crate engine form. Only a few units were available through special order, and they were all sold in just 48 hours. The guys at Demonology were among those lucky enough to get their hand on one, stuffed it inside a Challenger Demon, and performed a dyno test that you can watch below.

Hellephant Crate Engine
Photo: Stellantis North America
Rumors of a second production run of the Hellephant have been circulating for more than a year, but for now those who want to buy a crate HEMI have to settle for the Hellcat Redeye.

Some say that the HEMI is the greatest mass-produced, eight-cylinder ever conceived, while others are quick to oppose that statement. However, we can all agree that throughout its 70-year history, the HEMI became the most recognizable American-built V8 and one of the most legendary engines of all time.

Unfortunately, just like baby boomers had to witness the extinction of 1950s and 1960s versions, we also have to face the fact that the modern 392s and Hellcats will be gone soon, as the automotive industry is currently obsessed with electric motors instead of focusing more on the development of low-emission, synthetic fuels. When the third generation HEMI finally rides off into the sunset, we hope that Stellantis doesn’t decide to revive the legendary nameplate once again and slap it on the case of an electric motor.

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About the author: Vlad Radu
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Vlad's first car was custom coach built: an exotic he made out of wood, cardboard and a borrowed steering wheel at the age of five. Combining his previous experience in writing and car dealership years, his articles focus in depth on special cars of past and present times.
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