The Ultimate 5.7 HEMI Engine Guide. The 5.7 HEMI engine was introduced by Dodge in the 2003 model year and has been a workhorse for Chrysler and Dodge ever since. The 5.7 HEMI has made a name for itself over the past two decades, appearing in a diverse range of vehicles ranging from rugged Rams to high performance Chargers and Challengers. It produces 335-400 horsepower and 375-410 lb-ft of torque depending on the car or truck. With a few modifications, that can easily be upgraded, and it’s not uncommon to see a 500+ horsepower 5.7 HEMI in the wild.
This manual will teach you everything there is to know about the Chrysler/Dodge 5.7 HEMI engine. We’ll begin with a history of HEMI, then go over the 5.7 HEMI specs and applications, before delving into common issues and top mod upgrades for increased horsepower and torque. Let’s get this party started.
History of the Dodge 5.7 HEMI
As unbelievable as it may appear, the origins of Chrysler’s HEMI engine can be traced back to World War II. During the war, Chrysler developed two engines for the US Army: the AV-1790-5B, a V12 HEMI, and the XIV-2220, an inverted V16 HEMI. The V12 AV was used in the M47 Patton Tank, and the V16 XIV was used in the P-47 Thunderbolt aircraft. The XIV, in particular, produced over 2,500 horsepower and could reach speeds of over 500 mph.
From 1951 to 1959, Chrysler developed the first generation of HEMIs for automobiles after the war. These came in inline-six and V8 configurations, with displacement ranging from 240-392 cid. The second generation of Chrysler HEMI, known as the iconic 426 HEMI, lasted from 1964 to 1971. This HEMI engine powered some of the nastiest muscle cars of the 1960s and is now one of the most sought-after collectors engines. In Top Fuel racing applications, some versions have been modified to produce more than 10,000 horsepower.
The All-New HEMI
After 1971, Chrysler and Dodge discontinued production of the 426 HEMI, owing primarily to emissions and fuel economy concerns. Fortunately, the HEMI design was revived in 2003, with the 5.7 V8 leading the way for the third generation. Initially, it was used to power trucks such as the Ram 1500, 2500, and 3500, but this time with fuel injection. The 5.7 HEMI was soon powering high-performance sedans and muscle cars like the 300C, Charger, and Challenger.
Since then, the 345 HEMI has been a mainstay in the Chrysler and Dodge lineups, and Jeep has recently begun using it in the Wagoneer. It has received numerous awards, including inclusion on Ward’s 10 Best Engines List from 2003 to 2007, and again in 2009. The engine is still in production today, with over 1 million engines sold, but it may be phased out soon.
Dodge 5.7 HEMI Engine Specifications
Vehicle Applications for the Chrysler 345 HEMI
The Chrysler 5.7 HEMI engine has been used in the following vehicles:
- Ram Pickup from 2003 to the present
- Dodge Durango from 2004 to the present.
- From 2005 to the present, Chrysler 300C/S
- Dodge Magnum R/T 2005-2008
- Jeep Grand Cherokee 2005-Present
- Dodge Charger R/T from 2006 to the present
- Jeep Commander 2006–2010
- Chrysler Aspen 2007-2009
- Dodge Challenger R/T (2009-Present)
- Jeep Wagoneer from 2022 to the present
Basics of the Chrysler 345 HEMI Engine Design
The Chrysler/Dodge 5.7 HEMI engine is a 90° V8 with a displacement of 5.7 liters (345 cid). It has a cast iron block and a cast aluminum head. HEMI engines have hemispherical combustion chambers, as opposed to traditional flat-topped motors. This has both benefits and drawbacks. On the one hand, it allows the spark plug to be placed at the top center, resulting in a closer ignition of the air/fuel mixture. It also allows for massive intake and exhaust valves, resulting in excellent power.
One disadvantage is that these engines are frequently heavier than others. Because of the shape of the chamber, they are also largely limited to two valves per cylinder. Nonetheless, for most people, they provide more power than comparable displacement non-HEMI engines and sound fantastic. The Chrysler Gen III HEMIs have deep skirt cylinders and a dual-spark plug design. Multi-point sequential fuel injection is standard on the third generation of HEMIs.
The 5.7 V8 is equipped with an overhead valve (OHV) valve train and a single in-block camshaft. Each cylinder has two valves, for a total of sixteen valves. For simplicity, the HEMI employs an old-school pushrod design due to the OHV valve train. The pistons are made of hypereutectic aluminum alloy, while the connecting rods are made of powdered metal. The crankshaft is made of nodular iron.
Related : The Jeep Wrangler Reliability and Issues
The 2009 HEMI Upgrades
Chrysler and Dodge significantly improved the 5.7 HEMI for the 2009 model year. One of the biggest was adding variable valve timing (VVT) to the valve train and more aggressive camshafts. This resulted in a smoother power band, increased peak power, and improved fuel economy. For increased flow, the aluminum cylinder head and intake manifold were also revised.
Dodge also strengthened the crankshaft and connecting rods, as well as the cylinder block. In 2009, compression increased from 9.6:1 to 10.3:1. Some models also have a Multi-Displacement System, also known as MDS, which pretty much everyone has hated. MDS is essentially cylinder deactivation technology that increases fuel economy while decreasing emissions output. Only HEMIs with automatic transmissions have this technology. Check out our 5.7 and 6.4 HEMI MDS Guide for a more in-depth look at these engines.
Dodge 5.7 HEMI Reliability and Common Issues
With its 20th anniversary approaching, it should come as no surprise that the 345 HEMI has a reputation for dependability. It’s not the most durable engine Dodge has ever built, but it can more than hold its own in terms of longevity. The HEMI 5.7 is fantastic considering it has 300+ horsepower and can tow a decent amount of weight.
However, there are a few engine-related issues that are common. The most common issues with the Dodge 5.7 V8 are engine ticking, exhaust manifold bolts, the MDS system, and misfiring.
In addition, we have a written 5.7 HEMI common problems and reliability guide. We’ll only summarize the most important points here, so watch the video or read the article for a more in-depth look.
The Most Common Dodge 5.7 V8 Issues
- Tick of the Engine
- Bolts for the Exhaust Manifold
- System for Multiple Displacements (MDS)
- Misfires
While the severity of engine ticking on the 5.7 HEMI is debatable, any problems are usually related to the lifters or rollers. These are prone to insufficient oil flow and do not perform well with increased horsepower from mods. Still, most cars with these issues have well over 100,000 miles on them, so it’s not a common problem.
Broken exhaust manifold bolts are next. The exhaust manifold is made of cast iron, and after repeated heat cycling, bolts can become stuck and seized. They have the potential to break and cause serious exhaust leaks, so keep an eye on them.
The much-maligned MDS system is also known to occasionally cause premature spark plug fouling and insufficient lubrication. This can lead to misfiring and other problems. While the MDS does not fail in most cases, the above issues can reduce overall reliability.
Again, we consider the 345 HEMI engine to be very reliable, and the fact that over 1 million have been produced should be a pretty good indicator of how well they hold up. The key, as with most engines, is proper and timely maintenance with high-quality parts and lubricants.
Performance and Upgrades for the Chrysler 5.7 HEMI
The 345 HEMI is already a high-performance machine right out of the box. It produces 395 horsepower and more than 400 lb-ft of torque in Ram models. This makes it ideal for serious towing or burning rubber. It produces 375 horsepower and over 400 lb-ft of torque inside the Challenger and Charger, making it a formidable drag racer.
Furthermore, the HEMI is ripe for modification to increase horsepower and torque. The 345 HEMI naturally aspirated can produce nearly 500 horsepower, and with forced induction, the sky is the limit. Fortunately, we’ve already written a large number of 5.7 HEMI upgrade articles, so we’ll go over them here.
345 HEMI Upgrade Manuals
If you’re looking for the best Dodge 5.7 HEMI upgrades, start with tuning, intakes, headers, cat back exhausts, and camshafts. These are the most basic and cost-effective methods for increasing power without breaking the bank. For most people, simply adding tuning is a great way to increase performance without having to install any hardware. The installation is simple, and the gains range from 5-15% in horsepower and torque.
Cold air intakes, headers, and cat back exhausts are great places to start if you want to start with bolt-ons and hardware mods for increased power and noise. They will improve engine power by increasing air flow in and out of the engine. Then, depending on their size and aggressiveness, camshafts are fantastic ways to boost performance and broaden the power band.
We have guides with several recommendations for upgraded 345 HEMI cold air intakes and 345 HEMI headers. Furthermore, we investigated upgraded 5.7 HEMI throttle bodies and 5.7 HEMI camshafts. Check out our 5.7 HEMI intake manifold upgrade guide for more information on basic bolt-ons.
We have a 345 HEMI supercharger upgrade guide for those looking for serious horsepower. We have a Ram 1500 headers upgrade guide if you have a Ram 1500 with the 345 HEMI.
Summary of the Dodge 5.7 HEMI Engine
For many years, the 5.7 HEMI engine was one of the top choices in the Chrysler, Dodge, and Jeep lineups. You’re looking at nearly 400 horsepower and torque at a minimum, allowing you to tow family trailers or burn serious rubber at the drag strip. If that’s not enough, some simple bolt-on mods can get you close to 500 horsepower, and forced induction can get you anywhere else you want to go.
Even if you keep the car stock, the engine is extremely dependable. Though there are a few common issues that have arisen over the years, the 345 HEMI will last a very long time if properly and timely maintained.
Do you have or have you ever had a 345 HEMI in your garage? Are you thinking about a new build for your 5.7 MOPAR V8? Please let us know in the comments!
