Engines have long served the purpose of converting fuel into mechanical energy that powers the engine. Over the years, different types of engines are developed with different sets of advantages and disadvantages. Some are more commonly used in cars while others are seen only in specific types of vehicles. A Hemi engine is one developed mainly for race cars that require more power.
Anatomically, a Hemi engine is an engine shaped hemispherically consisting of pistons with rounded tops. In this guide, we will discuss all the details of a Hemi engine.
What Is a Hemi Engine?
A Hemi engine has a hemispherical-shaped combustion chamber. This type of engine has cylinders with a dome-shaped head rather than the traditional flat-headed ones. The Hemispherical combustion chamber offers more power as compared to a conventional engine. This is due to the higher compression ratio of Hemi engines.
Brief History of Hemi Engines
The Hemi engine was initially manufactured in a car by a Belgian company named Pipe in 1905. After that, Alfa Romeo, Peugeot, and Riley manufactured Hemi engines as well. Alfa Romeo and Peugeot also powered their Grand Prix racing cars with a Hemi engine.
To get your hands on an Alfa Romeo or Peugeot car model, you can explore these options:
First Generation Hemi Engine
Chrysler was dubbed a Hemi-powered car in 1951, after World War II. It featured a V8 Hemi engine named ‘FirePower’, delivering 180 horsepower with a displacement of 5.4 litres (331 cubic inches). This was the first generation Hemi engine which was manufactured as Fire Dome in Desoto cars and as Red Ram for Dodge cars.
Second Generation Hemi engine
Second-generation Hemi engines grew in size and displacement. In the history of Hemi engines, the 7.0-litres (426-cubic inches) engine was the first to wear the nameplate ‘Hemi’, which some called the ‘Elephant Engine’ as well. It was originally built for Plymouth Belvedere for NASCAR racing.
The Hemi-powered racing car was outlawed by NASCAR in 1965 due to Chrysler’s lack of Hemi-equipped street cars. Chrysler soon released the street Hemi cars. It featured a lower compression ratio of 10.25:1, milder intake and exhaust manifolds, and a replacement camshaft capable of delivering 425 horsepower.
The Hemi-street cars included Dodge’s Challenger, Charger, Coronet, Super Bee and Dart SS. Whereas the Plymouth released Barracuda, Belvedere, GTX, Satellite, Road Runner, and Super Bird as Hemi-street cars.
Third-Generation Hemi Engine
The third-generation Hemi engine in cars was not limited to racing and high-end performance cars. Rather, it was open for anyone to drive. Some examples of third-generation 5.7-litres Hemi engines include Chrysler Aspen and 300C; Jeep Grand Cherokee and Commander; and Dodge Challenger, Magnum and Charger.
The 6.1-litres Hemi engines were featured in Chrysler 300C, Jeep Grand Cherokee, and Dodge Challenger and Charger.
How Does a Hemi Engine Work?
In a Hemi engine, the combustion chamber is hemispherical. For that reason, the Hemi pistons also have a dome-shaped head with twin spark plugs in each cylinder and open, angled fuel and exhaust valves. These valves open on opposite sides of a combustion chamber. These valves are much larger than inline valves, accounting for a better flow of fuel and air through the engine.
Such a configuration allows a Hemi engine to exhibit optimal mixing of fuel and air, higher compression ratio, higher power output, and extreme air intake through the manifold. Hemi engines burn all the fuel in the cylinder, tapping all the potential energy.
A higher compression ratio generates greater heat, combustion and energy. This all happens due to Hemi’s angled crankshaft. Moreover, Hemi pistons conserve heat better than conventional engines. The shape and size of the Hemi pistons help in creating pressure in the cylinder walls due to heat preservation and reducing heat loss. This, in turn, allows higher pressure and more fuel combustion.
Advantages and Disadvantages of Hemi Engine
It is a universal fact that no machine can be 100% efficient. For that reason, there are some advantages and disadvantages of Hemi engines as well. Let’s take a look at what they are.
Advantages of Hemi Engine
The key advantages of a Hemi engine are detailed below.
- Less Heat Loss: Due to the small surface area of the Hemi chamber, less heat escapes the chamber and peak pressure is higher.
- Improved Airflow: The large-sized valves of a Hemi engine allow extensive airflow through the engine.
- Angled Crankshaft: The angled crankshaft of a Hemi engine allows maximum cylinder pressure that helps in the extraction of all energy.
- Higher Power Output: The higher compression ratio of a Hemi engine results in greater air compression in the cylinder. This results in greater combustion as more fuel is used, generating a higher power output.
Disadvantages of Hemi Engine
The disadvantages of a Hemi engine are detailed below.
- Heavier: A Hemi engine is heavier than other conventional engines due to its design.
- Expensive: Hemi engines are more expensive than conventional engines since they offer greater power output.
That’s a wrap on all about Hemi engines and their functioning. You can check the latest Dodge Charger Orange GT Edition equipped with a Hemi engine. Moreover, Hemi engines have been playing their role in the automotive industry for a long time. If you are searching for a Hemi engine-equipped car, you can consider one of these used car models:
- Used Dodge Challenger for sale in the UAE
- Second-hand Dodge Charger for sale in the UAE
- Used Jeep Grand Cherokee for sale in the UAE
Stay tuned to the UAE’s leading auto blog for more information on car parts and accessories.
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