The 5.7-liter HEMI V-8 was installed in the Jeep CJ66 concept vehicle with a Mopar 345 Crate HEMI Engine kit.

The 5.7-liter HEMI V-8 was installed in the Jeep CJ66 concept vehicle with a Mopar 345 Crate HEMI Engine kit. 

Mopar | November 10 2016

Heart Transplant: Classic Mopar Lines, Modern HEMI Power

The HEMI® V-8 engine is the heart of many of today’s most-popular FCA US vehicles. The 5.7-liter and 6.4-liter V-8s combine healthy amounts of horsepower and torque with refinement and smoothness.

We’re not the first to consider this: What if you transplant the HEMI V-8 from a modern-day muscle car such as the Dodge Charger or Challenger into one of the legendary Dodge or Plymouth muscle cars from the 1960s and early ‘70s? It would be the best of both worlds.

Now, it’s easier than ever.

Mopar’s new 345-cubic-inch (5.7-liter) and 392-cubic-inch (6.4-liter) Crate HEMI Engine Kits, unveiled at the 2016 Specialty Equipment Market Association (SEMA) show in Las Vegas, take a lot of the guesswork out of upgrading a pre-1975 vehicle with the power of a modern V-8.

Consider this: A brand-new 1971 Plymouth ‘Cuda fitted with a 426 HEMI V-8 was advertised with 425 gross hp (tested on a stand with no accessories) and 350 net hp (tested with accessories.) Dropping in a 2014 or newer 5.7-liter HEMI V-8 with the Mopar Crate HEMI Engine Kit delivers 383 hp. Make it a 6.4-liter HEMI and you get 485 hp.

The magic of Mopar’s Crate HEMI Engine Kit is the included powertrain control module (PCM), loaded with a factory-certified tune. It ensures that the transplanted V-8 runs as good as possible. The PCM is unlocked, so tuners can make changes to the software if they decide to upgrade engine components such as the camshaft.

“With the PCM we’re getting the full potential out of the engine and it’s safe,” says Ed Hessell, Mopar Performance Parts Manager. “A lot of tuners can make power all day long by leaning it out.’ Well, our HEMI doesn’t like to run really lean, it likes a lot of fuel to make power. That’s what makes the calibration in our PCM so important.”

The Crate HEMI Kit also contains a water-tight power distribution center, accelerator pedal with throttle position sensor, oxygen and charge air temperature sensors and wiring harnesses for the engine and chassis. Mopar has also created kits of popular accessories for the HEMI engines – power steering, air conditioning, front end accessory drive (FEAD) – to make this a true plug-and-play swap. You just need to add engine mounts.

“Our team has worked the last two years to create a package with factory-validated parts and the factory calibration,” says Hessell. “That’s essential when you’re working with systems that have variable cam timing, and the 6.4-liter has a dual-plane intake manifold that has to be actuated. That’s a challenge for many aftermarket options.”

Note that the components in the Crate HEMI Engine Kit are engineered to work with a manual transmission. You can bolt up an automatic but be prepared to tinker – the calibration in the PCM does not contain enough spark advance for some idle on a transmission with a torque converter, and the kit does not include provisions for a throttle kick down cable, so you would have to command shift changes manually.

Selecting your own gears with a clutch pedal is the best way to roll with your muscle car, in our humble opinion.

The potential for awesomeness is unlimited. Need inspiration? Just look at two Mopar concept vehicles unveiled at SEMA: the Dodge Shakedown Challenger and Jeep CJ66.

The Dodge Shakedown Challenger concept packs a modern 6.4-liter HEMI V-8, easily installed with a Mopar Crate HEMI Engine kit.

The Dodge Shakedown Challenger concept packs a modern 6.4-liter HEMI V-8, installed with a Mopar Crate HEMI Engine kit.

Underneath the 1971-era sheetmetal of the Dodge Shakedown Challenger is a modern 6.4-liter HEMI V-8, transplanted with the components of the 392 Crate HEMI Engine Kit. The HEMI’s 485 hp flows to the rear wheels through a six-speed manual transmission borrowed from the Dodge Viper.

The concept hood of the Jeep CJ66 covers a 5.7-liter V-8 installed with the 345 Crate HEMI Engine Kit. That 383 hp, augmented with a Mopar cold air induction kit, cat-back exhaust system and 35-inch tires and beadlock wheels accent the serious off-road nature of this Jeep.

Getting the Crate HEMI Engine kit is easy. Head to the parts department of your favorite Chrysler-Dodge-Jeep-Ram dealer, or visit www.Mopar.com/CrateHEMI. The kit carries a manufacturer’s suggested retail price of $1,795. You can supply your own modern HEMI V-8 or Mopar carries fresh 5.7-liter and 6.4-liter V-8s for purchase.

Either way, it’s easier than ever to put a HEMI in your classic car or truck.

Mopar Or No Car!

Dale Jewett

Do you know your blood type? Mine is 100 octane (not your standard blood bank classification). At any given moment, I’m thinking about cars – driving one, fixing one, buying one or (in my dreams) restoring one. So I love to tell stories that involve horsepower, brake and wheel diameters
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Do you know your blood type? Mine is 100 octane (not your standard blood bank classification). At any given moment, I’m thinking about cars – driving one, fixing one, buying one or (in my dreams) restoring one. So I love to tell stories that involve horsepower, brake and wheel diameters and 0-to-60 times – and the people who make it happen. Because behind every awesome vehicle are amazing people with vision and the desire to make it a reality. I cover Mopar, Dodge, SRT and motorsports for FCA Digital Media. I learned to drive on a 1973 Jeep CJ-5 with the rare Super Jeep option package and three-speed manual transmission. I still belong to the dwindling club of people who prefer to shift their own gears, and think the best way to drive is with the top down!