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Historically, this designation has been used by Chrysler for its vehicles powered by Hemispherical cylinders, which achieve better heat distribution and combustion. Nowadays, these are large-volume engines with 6 or 8 cylinders, some of which can be switched off while driving in order to reduce fuel consumption. They are equipped with two spark plugs per cylinder and a variable valve opening system.

Of course, their existence and popularity due to the construction and use are related to the US market and the cars that are present in that market. As we wrote at the beginning, they are made by the Chrysler brand, and they are known for their construction, which has a special head and hemispherical combustion space (hemispherical shape), which achieves better efficiency and heat distribution and combustion. Today, when HEMI is mentioned, it refers to large-volume engines with 6 or 8 cylinders, some of which can be switched off while driving in order to reduce fuel consumption. They have two spark plugs per cylinder and a variable valve opening system.

Hemi has always been reserved for the most powerful engines of a certain car rank. Most often of sports rank… Too expensive to make, but completely specific in driving. High fuel consumption, but a phenomenal sound that always makes you press the accelerator pedal again. Thanks to this unit, American sports cars got the name “muscle”. Technically, the HEMI engine is very similar to today’s standard unit. It also has cylinders, pistons, crankshaft, camshaft, valves. History is written only on the basis of a small modification HEMI is not an abbreviation of a designation, but is a derivative of the English word> hemisphere.

What problems are common on these engines?

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Like any other engine, this one is accompanied by certain problems, and these are some of the most common.

Hemi tick

If there are typical problems with this type of engine, then it is definitely this one. What is it really about? It is about producing a sound similar to ticking, which could be the result of jamming the lifters grinding on the camshaft. It is recommended to avoid low-quality fuels, it is recommended to find quality injectors on the market.

Multi-Displacement System (MDS)

Modern Hemi engines are equipped with something called a Multi-Displacement System. The MDS shuts off four of the engine’s cylinders when cruising at a steady, constant speed. The intent behind this system is to improve fuel economy — and generally speaking, it certainly does. However, this objection does not apply specifically to the IMF but to the system as a whole. Some owners claim that they do not have problems with MDS and loud engine sound, which is especially pronounced when the vehicle has a spare drain valve. Learn more on

Ram weight

This is intended to help with gas mileage by means of shutting off cylinders upon activation. But, the weight of the RAM and its large nature takes a negative toll on it.

The MDS also causes a fluttering sound upon activation because of its incompatibility with exhausts.

High torque curves

This engine is susceptible to problems that range from- drop-in valve seats, oil consumption, damaged bearing, dry start-up, leaks in the head gaskets, scraping of the piston, wear of valve guide, knocking or low oil pressure, oil leakage, and issues with running.

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However, some of these problems have been addressed by a team of researchers to device more means and improve the reliability and durability of the engine.

The HEMI’s valves are allowed to be bigger because there’s more room on each side of the engine’s head. This makes up the airflow difference it loses from only having two cylinders as opposed to four or six.

HEMI engines also have a smaller surface area than flathead engines. Engines with flat tops sometimes have difficulty during the combustion process because the headwalls are colder, so more heat is lost. The HEMI engine eliminates this issue almost entirely because of its smaller width.

Hemi engine advantages:

  • More power
  • Reliability
  • Pleasure

Hemi engine disadvantages:

  • It’s heavier
  • It is limited to only 2 valves per cylinder
  • Fuel consumption
  • Expensive performance

Is it a good idea to rebuild my 5.7 Hemi?

Of course, it is. If you were satisfied with your car so far, this investment is more than justified. Still, the sum is quite high – $2,500 – 7,000. The reason for this is that some other factors like labor hours and additional engine parts are included.

While this is something no one can say specifically, tests have shown that you will be able to drive your vehicle between 200,000 and 300,000 miles. It is up to you to maintain the engine regularly, that is, to change the oil and perform routine checks from time to time. Take a few minutes for your four-wheeler and you’ll save yourself a lot of unplanned expenses.

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Final thoughts

The engine is the heart of the car. This means that if the “heart” does not “beat”, the car does not work either. Let’s therefore see how you can extend the life of, in this case, the diesel engine in your favorite tin pet.

Check the coolant level. Over time, the coolant becomes acidic due to the oxidation of ethylene or propylene glycol and, if neglected, can lead to the deterioration of other parts of the cooling system, such as the radiator. The level of acidity, but also alkalinity, is measured on the basis of pH value. If the pH is low, it means that the coolant has taken on acidic properties. If the pH is high, the properties are alkaline, which can lead to corrosion of the cooling system. Therefore, check the coolant regularly to make sure it is in a “golden” environment.

The engine oil level should be checked every 500 kilometers. And you can easily do it yourself. All you have to do is check the oil dipstick. Don’t pour too much oil as it is easier to add oil than to take it out later. This can cause leaks and smoke. In the instructions for use, you will find which oil you are allowed to use.

Be sure to remember that a lack of oil can lead to the most expensive repairs, so in some cases the entire engine needs to be replaced. The best time to check the oil is in the morning because the car was “resting” overnight.