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5.7 HEMI Engine Ultimate Guide

Chandler Stark

Meet Chandler

Chandler is an automotive expert with over a decade of experience working on and modifying cars. A couple of his favorites were his heavily modded 2016 Subaru WRX and his current 2020 VW Golf GTI. He’s also a big fan of American Muscle and automotive history. Chandler’s passion and knowledge of the automotive industry help him deliver high-quality, insightful content to TuningPro readers.

Dodge first released the 5.7 HEMI engine in the 2003 model year, and it has been a workhouse for Chrysler and Dodge ever since.  Appearing across a diverse range of vehicles from the rugged Rams to the high performance Chargers and Challengers, the 5.7 HEMI has more than made a name for itself over the past two decades. Depending on the car or truck, it makes between 335–400 horsepower, and 375-410 lb-ft of torque stock. That can easily be upgraded with a few mods, and it’s not uncommon to see a 500+ horsepower 5.7 HEMI in the wild.

This guide will cover everything you need to know about the Chrysler/Dodge 5.7 HEMI engine. We’ll start with the history of HEMI, go over the 5.7 HEMI specs and applications, and then we’ll tackle the common problems and top mod upgrades for increased horsepower and torque. Let’s get started.

*Previously, we looked at the Dodge 6.4 HEMI vs 5.7 HEMI, so make sure to give that a read, too. **The 5.7 HEMI is also referred to as the 345 HEMI, due to its 345 cid displacement. We’ll use both terms interchangeably.

***We also have a YouTube video on the 5.7 HEMI reliability if you’d like to view that first!

Dodge 5.7 HEMI History

As incredible as it might seem, the birth of Chrysler’s HEMI engine is actually related to the Second World War. During the war, Chrysler created two different engines for the U.S. Army, the AV-1790-5B, which was a V12 HEMI, and the XIV-2220, which was an inverted V16 HEMI. The Army used the V12 AV in the M47 Patton Tank, and the V16 XIV inside the P-47 Thunderbolt aircraft. The XIV in particular made more than 2,500 horsepower and could reach speeds of more than 500 mph.

Following the war, Chrysler developed the first generation of HEMIs for automobiles from 1951-1959. These included both inline-six and V8 configurations, and ranged from 240–392 cid in displacement. The second generation of Chrysler HEMI lasted from 1964-1971, you probably know it as the iconic 426 HEMI. This HEMI powered some of the nastiest muscle cars of the 1960s, and are some of the most sought out collectors engines today. Some versions have been modified to make more than 10,000 horsepower in Top Fuel racing applications.

The New HEMI

After 1971, Chrysler and Dodge stopped making the 426 HEMI due largely to emissions and fuel economy reasons. Luckily, they brought the HEMI design back in 2003, with the 5.7 V8 leading the way for the third generation. They initially 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 powering high performance sedans and muscle cars, like the 300C, Charger, and Challenger.

The 345 HEMI has been a mainstay in the Chrysler and Dodge lineup ever since, and recently Jeep started using it in the Wagoneer. It has gotten several accolades, including being on Ward’s 10 Best Engines List from 2003–2007, and 2009. The engine remains in production as of today, with over 1 million engines sold, though it may soon be on its way out.

Dodge 5.7 HEMI Engine Specifications

Engine Name 5.7 HEMI
Engine Family Gen III HEMI
Model Years 2003-Present
Displacement 5.7 L (345 cid)
Aspiration Natural Aspiration
Configuration 90° V8
Compression Ratio 9.6:1; 10.3:1 (’09+)
Bore and Stroke 3.92” x 3.58” (99.49mm) x (90.88mm)
Valve Train OHV, 16 Valve, VVT (’09+)
Fuel System Electronic Fuel Injection
Head Material Cast Aluminum
Block Material Cast Iron
Horsepower Output 335-400 horsepower
Torque Output 375-410 lb-ft of torque

Chrysler 345 HEMI Vehicle Applications

The Chrysler 5.7 HEMI has appeared in the following vehicles:

  • 2003–Present Ram Pickup
  • 2004–Present Dodge Durango
  • 2005–Present Chrysler 300C/S
  • 2005–2008 Dodge Magnum R/T
  • 2005–Present Jeep Grand Cherokee
  • 2006–Present Dodge Charger R/T
  • 2006–2010 Jeep Commander
  • 2007–2009 Chrysler Aspen
  • 2009–Present Dodge Challenger R/T
  • 2022–Present Jeep Wagoneer

Chrysler 345 HEMI Engine Design Basics

5.7 HEMI engine
Credit: Greg Gjerdingen/Wikipedia

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 with traditional flat-topped motors, the HEMI engines have hemispherical shaped combustion chambers. This has both advantages and disadvantages. On one hand, it allows for the spark plug to be placed at top center, meaning the air/fuel mixture is ignited at a shorter distance. It also allows for huge intake and exhaust valves to be fitted, making for excellent power.

Some of the downsides are that these engines are often heavier than others. They are also largely limited to 2 valves per cylinder, because of the shape of the chamber. Still, for most people they increase power over similar displacement non-HEMI engines, and sound glorious. The Chrysler Gen III HEMIs use a dual-spark plug design and have deep skirt cylinders. The third generation of HEMIs features multi-point sequential fuel injection.

The 5.7 V8 has an overhead valve (OHV) valve train with a single in-block camshaft. There are 2 valves per cylinder, for 16 valves total. Due to the OHV valve train, the HEMI uses an old school pushrod design for simplicity. The pistons are made from hypereutectic aluminum alloy and connecting rods from powdered metal. The crankshaft is nodular iron.

The 2009 HEMI Upgrades

For the 2009 model year, Chrysler and Dodge made significant upgrades to the 5.7 HEMI. One of the biggest was adding variable valve timing (VVT) to the valve train and more aggressive camshafts. This allowed for a smoother power band with increased peak power and better fuel economy. The aluminum cylinder head and intake manifold were also revised for increased flow.

Dodge also improved the cylinder block and made the crankshaft and connecting rods stronger. Compression increased too in 2009, 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. Essentially, MDS is cylinder deactivation technology to increase fuel economy and reduce emissions output. Only automatic transmission HEMIs are equipped with technology. Previously, we looked in-depth with our 5.7 and 6.4 HEMI MDS Guide, so make sure to check that out.

Dodge 5.7 HEMI Common Problems and Reliability

Coming up on its 20th anniversary, it should come as little surprise that the 345 HEMI has a reputation for reliability. It’s not the most bulletproof engine Dodge has ever created, but it can more than hold its own for longevity. Considering it makes 300+ horsepower and is capable of towing some pretty good weight, the HEMI 5.7 is fantastic.

However, there are a few common problems that are associated with the engine. In no particular order, the most common problems for the Dodge 5.7 V8 are engine ticking, exhaust manifold bolts, the MDS system, and misfiring.

Check out our video on the 5.7 HEMI common problems and reliability!

We also have a written 5.7 HEMI common problems and reliability guide, too. We’ll just summarize the most important parts here, so make sure to watch the video or check out the article for a more in-depth look.

Most Common Dodge 5.7 V8 Problems

  • Engine Tick
  • Exhaust Manifold Bolts
  • Multi-Displacement System (MDS)
  • Misfires

While the severity of engine ticking on the 5.7 HEMI is debatable, if any issues do arise they are usually related to the lifters or rollers. These are somewhat prone to inadequate oil flow, and they also do not do well with increased horsepower from mods. Still, most cars with these issues are well north of 100,000 miles, and it’s not a very prevalent issue.

Next up are broken exhaust manifold bolts. The exhaust manifold is made of cast iron, and bolts can often become stuck and seized after repeated heat cycling. They can break and cause serious exhaust leaks, so it’s a good idea to keep an eye on them.

The much maligned MDS system is also known to cause problems with premature spark plug fouling and inadequate lubrication at times. This can result in misfiring and other negative problems. While for the most part the MDS doesn’t fail, it can reduce overall reliability due to the above issues.

Again, we consider the 345 HEMI to be a very reliable engine, and the fact that over 1 million have been made should be a pretty good indication of how well they hold up. Like most engines, the key is proper and timely maintenance using highly quality parts and lubricants.

Chrysler 5.7 HEMI Performance and Upgrades

Out of the box, the 345 HEMI is already a performance machine. In the Ram models, it makes 395 horsepower and more than 400 lb-ft of torque. Making it ideal for either serious towing or burning rubber. Inside the Challenger and Charger it makes 375 horsepower and over 400 lb-ft of torque, so it’s very formidable at the drag strip.

In addition, the HEMI is ripe for upgrading with mods for increased horsepower and torque. It’s possible to make nearly 500 horsepower on the 345 HEMI naturally aspirated, and with forced induction the sky’s the limit. Luckily, we’ve already written up a huge number of 5.7 HEMI upgrade articles, so let’s discuss them here.

345 HEMI Upgrade Guides

For those looking for the 5 best Dodge 5.7 HEMI upgrades available, you’ll want to start with tuning, intakes, headers, cat back exhausts, and camshafts. These are the simplest and most cost effective ways to make increased power without breaking the bank. For most people, simply adding tuning is a great way to get some more performance without having to do any hardware installations. Installation is pretty easy and gains range from 5-15% horsepower and torque.

However, if you do want to start with bolt-ons and hardware mods for increased power and increased noise, cold air intakes, headers, and cat back exhausts are great places to start. They will increase air flow in and out of the engine, allowing for better power. After that, camshafts are phenomenal ways to increase performance and broaden the power band, depending on their size and aggressiveness.

We have guides for upgraded 345 HEMI cold air intakes and 345 HEMI headers that have several recommendations. In addition, we have also looked at upgraded 5.7 HEMI throttle bodies, 6.4 HEMI throttle and 5.7 HEMI camshafts. Completing basic bolt-ons, check out our 5.7 HEMI intake manifold upgrade guide.

For those of you looking at some serious horsepower, we have a 345 HEMI supercharger upgrade guide. If you have a Ram 1500 with the 345 HEMI, we have a specific Ram 1500 headers upgrade guide.

Dodge 5.7 HEMI Engine Summary

For many years, the 5.7 HEMI has been one of the top options of the Chrysler, Dodge, and Jeep lineups. At a minimum, you’re looking at nearly 400 horsepower and torque, allowing you to alternatively tow family trailers or burn serious rubber at the drag strip. If that’s enough, some basic bolt-on mods can bring you to nearly 500 horsepower, and forced induction can take you wherever else you want to go.

Even if you decide to keep the car stock, the engine is extremely reliable. Though there are a few common problems that have crept up over the years, for the most part the 345 HEMI will last a very long time within proper and timely maintenance.

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

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  1. What should I do?
    I have (new to me) a 2006 Jeep Grand Cherokee 5.7L HEMI with 180k miles.
    It has NO tick.
    I will check the Manifod bolts.
    Suggestions on type and gap of new spark plugs?
    What oil should I use? And how often should it be changed?
    What else should I look for? And/or should I make any upgrades? If so what kinds?

    1. Tobin8r,
      Congratulations on your new HEMI-powered Jeep! If the car is otherwise stock, we suggest sticking with the OEM recommended spark plugs and weighted oil. According to Mopar, spark plugs need to be changed every 60,000 miles and oil changes should be every 3,000 miles. We have a large host of HEMI 5.7 content, we have more maintenance guides as well as upgrade guides.

      All the Best,

  2. i have a 2008 chrysler aspen with the 5.7 ..I have water in the pistons .I took out the spark plugs and the water shot out like a geyser .I put the plugs back in and they all have a compression of around 190 yet the car will not run more than 5 miles per hour but goes good in reverse . Im wondering if 1 or both converters are plugged but there doesnt seem to be any leaks when closing off the tail pipe .The AOS relay and a smaller fuel pump and low battery relay keep ticking . I am now confused as th what could be the cause or what to do next ..any clues please ?

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