5.7 Ultimate HEMI Engine Guide: Specs, Reliability, and Best Mods (2023)

Dodge first released the 5.7 HEMI engine in the 2003 model year and it has been a work place for Chrysler and Dodge ever since. Appears on a variety of vehicles, from rugged Rams to high-performance vehiclesChargers and Challengersthe 5.7 HEMI has made more than a name for itself over the past two decades. Depending on the car or truck, it produces between 335 and 400 hp and 375 to 410 lb-ft of torque. This can easily be upgraded with a few mods, and it's not uncommon to see a HEMI 5.7 with 500+ horsepower in the wild.

This guide contains everything you need to know about the Chrysler/Dodge 5.7 HEMI engine. We'll start with the HEMI story, go through the 5.7 HEMI specs and applications, then tackle the most common issues and top mod updates for more power and torque. Let's start.

*Previously we looked at themDodge 6.4 HEMI vs 5.7 HEMI, so read that too. **The 5.7 HEMI is also known as the 345 HEMI due to its 345 cid displacement. We will use both terms interchangeably.

***We also have a YouTube video on the 5.7 HEMI reliability if you want to check it out first!

History of Dodge 5.7 HEMI

Incredibly, the birth of Chrysler's HEMI engine is actually related to World War II. During the war, Chrysler made two different engines for the US Army, the AV-1790-5B, a V12 HEMI, and the XIV-2220, an inverted V16 HEMI. The Army used the V12 AV in the M47 Patton Tank and the V16 XIV in the P-47 Thunderbolt aircraft. The XIV in particular produced over 2,500 hp and could reach speeds of over 800 km/h.

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After the war, Chrysler developed the first generation of HEMIs for automobiles from 1951 to 1959. These included in-line six-cylinder and V8 configurations with displacements from 240 to 392 cid. The second generation Chrysler HEMI lasted from 1964 to 1971, you probably know it as the legendary 426 HEMI. This HEMI powered some of the meanest muscle cars of the 1960s and is one of the most desirable collector engines today. Some versions were modified to produce over 10,000 hp in high-end fuel racing applications.

The new HEMI

After 1971, Chrysler and Dodge stopped making the 426 HEMI primarily for reasons of emissions and fuel economy. Fortunately, they brought the HEMI design back in 2003, with the third generation 5.7 V8 leading the way. They first used it to power trucks like the Ram 1500, 2500 and 3500, this time with fuel injection. Within a few years, the 5.7 HEMI was also fitted to high-performance sedans and muscle cars such as the 300C, Charger and Challenger.

Since then, the 345 HEMI has been a mainstay in the Chrysler and Dodge lines, and recently Jeep started using it in the Wagoneer. It has won numerous accolades, including being on Ward's Top 10 Engines list from 2003 to 2007 and 2009. The engine remains in production to this day, with over 1 million engines sold, although that may be the case.right out.

Dodge 5.7 HEMI Engine Specifications

Motorname5.7 HEMI
engine familyGen III HEMI
model years2003-present
change5,7 l (345 cid)
Aspirationnatural effort
Construction90° V8
compression ratio9,6:1; 10,3:1 ('09+)
scoop and blow3,92" x 3,58" (99,49 mm) x (90,88 mm)
valve trainOHV, 16 Ventile, VVT ('09+)
fuel systemelectronic fuel injection
header materialAluminiumguss
block of materialcast iron
performance in horses335-400 PS
torque output375-410 lb-ft Drehmoment

Chrysler 345 HEMI vehicle applications

The Chrysler 5.7 HEMI appeared on the following vehicles:

  • pickup truck RAM 2003-present
  • 2004-present Dodge Durango
  • 2005-presente Chrysler 300C/S
  • 2005–2008 Dodge Magnum R/T
  • 2005-presente Jeep Grand Cherokee
  • 2006-present Dod Charger R/T
  • Jeep Commander 2006–2010
  • Chrysler Espe 2007–2009
  • 2009-presente Dodge Challenger R/T
  • 2022-presente Jeep Wagoneer

Chrysler 345 HEMI engine design fundamentals

5.7 Ultimate HEMI Engine Guide: Specs, Reliability, and Best Mods (1)

The Chrysler/Dodge 5.7 HEMI is a 90° V8 engine with a total displacement of 5.7 liters or 345 cid. It has a cast aluminum head and cast iron block. Compared to traditional flat-top engines, HEMI engines have hemispherical combustion chambers. This has advantages and disadvantages. For one thing, it allows the spark plug to be placed in the top center, which ignites the air-fuel mixture over a shorter distance. It also allows the installation of huge intake and exhaust valves, which provides excellent performance.

Some of the downsides are that these engines are often heavier than others. They are also largely limited to 2 valves per cylinder due to the chamber shape. Still, for most people, they boost power over similarly displaced non-HEMI engines and sound glorious. Chrysler Gen III HEMIs use a dual spark plug design and have deep rimmed cylinders. The third generation of HEMIs feature sequential multipoint fuel injection.

(Video) 5.7L Hemi V8 Engine Comparison - 2003-08 vs. 2009+ – What’s the Difference? (Pre-Eagle vs. Eagle)

The 5.7 V8 has an OHV (overhead valve) valve train with a single overhead camshaft. There are 2 valves per cylinder, totaling 16 valves. Because of the OHV valve train, the HEMI uses an old-school pushrod design for simplicity. Pistons are made of hypereutectic aluminum alloy and connecting rods are made of sintered metal. The crankshaft is made of nodular iron.

Die HEMI-Upgrades 2009

For the 2009 model year, Chrysler and Dodge made significant improvements to the 5.7 HEMI. One of the biggest was the addition of variable valve timing (VVT) to the valve train and more aggressive camshafts. This allowed for a more consistent powerband with higher peak power and better fuel economy. The aluminum cylinder head and intake manifold have also been redesigned to increase flow.

Dodge also improved the cylinder block and made the crankshaft and connecting rods stronger. Compression was also increased in 2009 from 9.6:1 to 10.3:1. Some models also have a multi-shift system, also known as MDS, which almost everyone hated. Essentially, MDS is a cylinder deactivation technology to improve fuel economy and reduce emissions. Only automatic transmission HEMIs come with technology. Before that, we took a good look with our5.7 and 6.4 HEMI MDS Guide, so be sure to check that out.

Dodge 5.7 HEMI Common Issues and Reliability

As it celebrates its 20th anniversary, it's not surprising that the 345 HEMI is known for its reliability. It's not the most bulletproof engine Dodge has ever created, but it's more than good enough in terms of durability. Considering it makes over 300 horsepower and can tow a fair amount of weight, the HEMI 5.7 is pretty awesome.

However, there are some common problems associated with the engine. In no particular order, the most common Dodge 5.7 V8 problems are engine ticking, exhaust manifold bolts, MDS system, and misfire.

Watch our video 5.7 Common HEMI issues and reliability!


We also have a written5.7 Common HEMI issues and reliability guide, for. We've only summarized the most important parts here, so be sure to watch the video or read the article for a deeper dive.

The most common problems with the Dodge 5.7 V8

  • engine is running
  • exhaust manifold screws
  • Multiple Displacement System (MDS)
  • misfires

While the severity of engine ticking in the 5.7 HEMI is debatable, when problems do arise they are usually related to the lifters or rollers. These are a bit prone to poor oil flow and also don't handle the power boost from mods well. Still, most cars with these problems are well north of 100,000 miles, and it's not a very common problem.

Next are broken exhaust manifold bolts. The exhaust manifold is made of cast iron and the bolts can snag and stick after repeated heat cycling. They can break off and cause serious exhaust leaks, so it's a good idea to keep an eye out for them.

The much-maligned MDS system is also known to cause problems with premature spark plug fouling and intermittent insufficient lubrication. This can lead to misfires and other negative issues. Although MDS does not fail for the most part, it can reduce overall reliability due to the above issues.

Again, we think the 345 HEMI is a very reliable engine and the fact that over 1 million were made should be a good indication of how well it's handling itself. As with most engines, the key is proper and timely maintenance using quality lubricants and parts.

(Video) IS THE 5.7L HEMI A GOOD ENGINE? - TruckTalk #010

Chrysler 5.7 HEMI Performance and Updates

Out of the box, the 345 HEMI is already a performance machine. On Ram models, it produces 395 hp and over 400 lb-ft of torque. This makes it ideal for serious towing or burning rubber. In the Challenger and Charger, it makes 375 hp and over 400 lb-ft of torque, so it's very impressive on the drag strip.

Also, the HEMI is ready for an update with mods for more power and torque. It's possible to make around 500 horsepower with the naturally aspirated 345 HEMI, and with the supercharger, the sky's the limit. Fortunately, we've already written quite a number of 5.7 HEMI update articles, so we'll discuss them here.

345 HEMI Update Guides

For those looking for thisTop 5 Dodge 5.7 HEMI Updatesavailable you should start with tuning, intakes, manifolds, cat-back exhaust and camshafts. These are the easiest and most affordable ways to get more energy without breaking the bank. For most people, simply adding tuning is a great way to get a little more performance without having to do any hardware installation. Installation is quite easy and gains range from 5 to 15% in power and torque.

However, if you want to start with hardware screws and mods for more power and noise, cold air intakes, heads, and post-cat exhaust systems are a good place to start. They increase airflow in and out of the engine, allowing for better performance. After that, depending on size and aggressiveness, cams are phenomenal ways to increase horsepower and expand the powerband.

We have guides for upgrades345 HEMI cold air intakesE345 HEMI headerswho have several recommendations. We also review updates5.7 HEMI Throttle BodyE5.7 HEMI camshafts. To complete basic screws, check out our5.7 HEMI Intake Manifold Upgrade Guide.

For those looking for serious power, we have aHEMI 345 Compressor Upgrade Guide. If you have a Ram 1500 with the 345 HEMI we have a specialRam 1500 Header Upgrade Guide.

(Video) Hemi 5.7 MDS delete, Lessons Learned

Dodge 5.7 HEMI Engine Summary

For many years, the 5.7 HEMI was a top choice in the Chrysler, Dodge and Jeep lines. At the very least, you're looking at nearly 400 horsepower and torque, allowing you to tow family trailers or burn some rubber on the drag strip. If that's enough, a few simple mods can get you close to 500hp, and forced induction can get you where you want to go.

Even if you decide to keep the car in stock, the engine is extremely reliable. While some common issues have cropped up over the years, for the most part the 345 HEMI will last a long time with proper and timely maintenance.

Do you have a 345 HEMI in your garage or in your past? Considering a new build for your 5.7 MOPAR V8? Let us know in the comments below!


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