Known for its power, the Hemi engine has spent over 70 years on the market. Many of the world’s best cars and trucks use this engine, thanks to its unique design. Today, we’re going to take a look at what makes this engine so different from others out there and the history and development of the engine over the years. We’ll also discuss best practices for replacing cylinder heads in a Hemi – and when and why you might need to do this.
History of 5.7 Hemi Engine
The Hemi engine uses a hemispherical combustion chamber which is what makes this such an efficient and powerful engine option. Compared to flat piston heads, it increases the compression ratio for higher power. The design incorporates two spark plugs in each cylinder, which improves the fuel combustion process.
The history of this engine can be traced all the way back to 1945, when Chrysler first tested the design in a fighter aircraft during World War II. Taking the knowledge and experience they learned from this, they then introduced the FirePower engine in 1950, which was the original name for the Hemi. This engine was used in three different models in the 1951 range, including the Imperial, Saratoga, and New Yorker.
In 1964, the name Hemi was first introduced with the second generation of the engine. Two years later, the Street 426 Hemi was added to many of the most popular muscle cars of the time, such as the Dodge Charger. The third generation 5.7L Hemi was added to the 2003 Dodge Ram and is the first generation that went away from using the hemispherical design. These new engines improved both the speed and performance but aimed to lower emissions.
There’s also the option now of the 6.2L Hemi for increased horsepower. It’s still one of the best engines on the market today, and you’ll find it used in the Jeep Grand Cherokee SUV and Dodge Challenger. Further updates were done to the engine in 2009, improving fuel economy and emissions, and this newer engine is usually referred to as the 5.7L Eagle.
What Engines Are Comparable to a Hemi?
The Hemi is often compared to the EcoBoost that’s used in Ford pickup trucks. While they are quite different in many ways, the power and fuel economy they offer is very comparable. You may also find the Pentastar V6 is compared to the Hemi, as they both offer great value and benefits for drivers.
How Many Horsepower is a 5.7 Hemi Engine?
A 5.7 Hemi engine will offer you 395 horsepower. This figure applies to both the engines on offer today, including the one with eTorque mild hybrid technology. The engine can take your truck from 0 mph to 60 mph in just 6.5 seconds, showing how powerful and reliable it is.
What Vehicles Use the 5.7 Hemi Engine?
Chrysler, Dodge, and Plymouth vehicles use the Hemi engine to boost their performance and speed. The 5.7L Hemi is used on the Dodge Ram and Jeep Grand Cherokee currently. Sometimes called the Hellcat, the 6.2L Hemi can be found in the Dodge Charger, Dodge Challenger, and Ram TRX. This offers a whopping 700 horsepower, so it’s one of the most powerful engines on the market today.
Common Problems with Hemi Engines
While Hemi engines have been on the market for many years now, that doesn’t mean they don’t have a few issues from time to time. Although they are typically very reliable engines, you need to ensure you maintain your engine well for it to last the number of years you expect it to. Not all of the Hemi engines will have these issues, but many experience them more with age.
An engine tick is a commonly reported problem, which is often caused by exhaust manifold bolt failure or faulty lifters. Lifter roller problems are quite common as well, but these can be more difficult to diagnose. Look out for ticking, engine lights, and misfires. The newer 5.7L Eagle sometimes reports issues with the multi-displacement technology that’s used to shut down the cylinders. This technology bug can lead to an unnatural feeling when driving, but as it is a newer type of engine technology, we hope this problem reduces over time. Finally, dropped valve seals are another complaint we hear about as the vehicle ages or reaches higher mileage.
How Long Does a Hemi Engine Last?
With proper maintenance and care, a 5.7L Hemi engine can easily last between 250,000 and 300,000 miles. While earlier models had more of the issues we shared above, over time, the company has worked to make adjustments to ensure more of the engines reach this number of miles.
Replacing Cylinder Heads in a Hemi
As your engine starts to age, you may find that you need to replace the cylinder heads in the Hemi. Check out this video to learn more about the process and how you could potentially DIY this job. Keep in mind that cylinder head replacement often costs over $3,000 for the labor and parts, which is why some people opt to do this at home if they feel comfortable with the task. However, a professional will be able to give you their honest advice about whether this work is worth completing based on the age and condition of your Hemi engine.
The Hemi engine has a long and fascinating history and is still respected as one of the most powerful and reliable engines in the vehicle market. As you can see, there have been many changes to the engine over the years, but this is why it has stood the test of time. We encourage you to take good care of your Hemi engine if you want it to serve you for many years, replacing the cylinder heads if needed. With a well-maintained engine, you’ll be able to enjoy years of driving any of the vehicles which are fitted with a Hemi engine.
Buy Hemi Heads from Clearwater Cylinder
If you are the driver or the mechanic of a vehicle with a Hemi engine and need to purchase new or refurbished cylinder heads, then please give us a call. Locating the casting number on your Hemi engine or existing head will help us identify the correct cylinder head(s) for your specific vehicle.