14. 6.2-liter Hemi Demon V8
If you think the insane Hellcat V8 with 707 HP is not powerful enough, there is the 6.2-Liter Demon V8 built by the same guys in the Chrysler SRT department. This powerplant delivers 820 HP and is available in limited production. It is also in the track-ready Dodge Challenger Demon.
The Demon is more than a Hellcat with more boost and over 100 HP more. Even though these two engines share similar architecture and blocks, there are over 25 important differences between the two.
15. 6.4-Liter 392 Apache Hemi V8
The last engine on this list started as a crate engine that the Chrysler Mopar division produced. They based the Apache Hemi V8 on the revamped 5.7-liter version. The 392 is a naturally-aspirated Hemi with performance additions. The output is 532 HP and 510 lb-ft of torque. They introduced this engine in 2007 as a crate engine, but in 2011 they installed it in the Dodge Challenger SRT.
Since they offered this unit as a replacement engine and crate item, it proved to be popular with restomod guys. In fact, the 392 was the perfect replacement engine for people who wanted to restore older muscle cars but also give them a modern drivetrain and drivability. The 392 Hemi V8 with 532 horses had almost the same HP as the original 426 Hemi. But, it was much more docile on the street and easier on fuel, too.
The powerful and dependable Hemi engine is legendary and world-renowned. Fortunately, car manufacturers will continue to use the Hemi in future production models, improving it with each generation. No one wants to see the famous Hemi engine go away, so it should be around for many years to come.