Editor’s Note: This series counts down the Top 10 engines of all time—see how the voting was done by reading our initial post.

426 Street Hemi engine in a 1966 Plymouth Satellite
(Image/OnAllCylinders)

“That thing got a HEMI in it?”

Yes, your Top 10 Engines of All Time list does have a HEMI in it—and it’s the legendary Chrysler 426 HEMI “Elephant.”

History

Mopar is celebrating the 50th anniversary of the (Gen II) 426 HEMI in 2014.

How great is the mighty 426? When introduced as a race-only motor in 1964, it struck fear in Ford Motor Company execs and necessitated the #10 engine on this list: the Ford 427 SOHC. (You can learn more about the 427 SOHC in our earlier post). The 426 HEMI engine powered Richard Petty to an upset NASCAR win at Daytona in 1964, and 426-powered cars finished 1-2-3 at the event. The 426 HEMI was so dominant in its debut NASCAR changed its rules for engines, eliminating the use of limited-production, race-only engines and requiring all engines to be available in production vehicles.

It turned out to be a good news/bad news move for Mopar fans.

The new NASCAR rules led Chrysler to sit out the 1965 season, but the company used this time to develop a street version of the HEMI, which began appearing in 1966 Dodge and Plymouth B-Bodies. The street HEMI featured a lower compression ratio (10.25:1) than the race version and had milder timing and different intake and exhaust manifolds. Because this engine was available for production vehicles, Chrysler returned to NASCAR in 1966 and won countless races and numerous championships.

Nicknamed “the Elephant” for its size, the 426 HEMI was also quite the force on the dragstrip. A lighter drag racing package, referred to as A-990, debuted in the NHRA Super Stock class in 1965 in Dodge and Plymouth vehicles with altered wheelbases, launching the popularity of Funny Cars. With the introduction of the street HEMI in 1966, the original race version was essentially discontinued as drag racers were offered the street HEMI, which they could modify their own way. The race HEMI did still appear under the hoods of limited-edition Dodge Darts and Plymouth Barracudas in 1968.

Fun Facts

  • Chrysler produced only 75 race HEMI-powered Darts and 75 race HEMI-powered Barracudas for 1968.
  • To this day, a version of the 426 HEMI still powers every single Funny Car and Top Fuel engine regardless of being badged by other manufacturers.
  • The 426 HEMI was, in fact, under the hood of the 1969 Dodge Charger immortalized on The Dukes of Hazzard.
plymouth barracuda with 426 hemi shaker engine

Specifications

Chrysler’s original (Gen I) HEMI engine debuted in 1951 and featured revolutionary hemispherical-shaped combustion chambers. The second generation (Gen II) 426 was based on this design, but unlike the street-based Gen I HEMI, it was originally built specifically for racing. The slightly detuned street 426 HEMI offered 425 horsepower at 5,000 rpm and 490 ft.-lbs. of torque at 4,000 rpm.

The 426 HEMI was offered in many vehicles across the Dodge/Plymouth platforms. This impressive list includes the Dodge Coronet R/T and Coronet Super Bee, Dodge Charger, Plymouth Belvedere GTX, Plymouth Satellite, Plymouth Barracuda, and Plymouth Superbird. It was discontinued in 1971.

Modifications

If you’re lucky enough to own a (Gen II) 426 HEMI, here are some common upgrades for the “Elephant:”

Editor’s Note: This series counts down the Top 10 engines of all time—see how the voting was done by reading our initial post.

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Author: David Fuller

David Fuller is OnAllCylinders' managing editor. During his 20-year career in the auto industry, he has covered a variety of races, shows, and industry events and has authored articles for multiple magazines. He has also partnered with mainstream and trade publications on a wide range of editorial projects. In 2012, he helped establish OnAllCylinders, where he enjoys covering all facets of hot rodding and racing.