| Known for its muscle, the HEMI engine has been | | | | within the chamber burns more efficiently because |
| popular ever since it debuted in Chrysler's vehicles in | | | | less heat is lost to the limited surface area. |
| the early 1950s. The original model was a V-8 | | | | The second advantage involves the valve size. In a |
| configuration that offered drivers 180 horsepower. | | | | regular flat head design, the size of the fuel and |
| Today, that kind of power hardly seems worth a | | | | exhaust valves is limited due to their placement. In a |
| second glance, but in 1951, it turned heads. It wasn't | | | | spherical design, the size of the valves can be much |
| long before Chrysler, aware there was a growing | | | | larger. The larger the valves, the larger their |
| market for the HEMI, devoted their resources to | | | | corresponding openings during the 4-stroke |
| further developing the engine. By 1965, it offered 425 | | | | combustion process. That translates into more |
| horsepower. | | | | airflow. |
| The main ingredient behind the HEMI's enormous | | | | Drawbacks Of A HEMI |
| power and efficiency was the design of the | | | | There's one main drawback to a HEMI: the number |
| combustion chamber. Rather than relying upon a | | | | of valves it allows per cylinder. Because the top of |
| traditional flat design, the HEMI was curved at the | | | | the chamber is shaped like a ball, it can only fit two |
| top (similar to the top edge of a ball). This curvature | | | | valves. Many of the performance vehicles that are |
| eliminated much of the thermal inefficiencies suffered | | | | rolling off the factory floor today are taking |
| by the flat head engine. | | | | advantage of 4-valve cylinders. In the same way |
| In this article, we'll take a closer look at the pros and | | | | that larger valves offer more airflow, so too, do four |
| cons of the HEMI engine. To be sure, it's not the | | | | valves offer more airflow than two valves. |
| ideal design for every driver, but for some, it offers | | | | There is a smaller reason HEMI has recently fallen out |
| unparalleled performance. | | | | of favor with drivers who need immense power in |
| Advantages Of A HEMI | | | | their engines: the size of the combustion chamber. |
| There are two main advantages to a HEMI engine. | | | | The design does not allow the chamber to be smaller. |
| The first advantage involves the amount of surface | | | | Meanwhile, automakers are trying to reduce the |
| area within the combustion chamber. To understand | | | | chamber's size to further limit surface area and heat |
| why, it's important to review how your vehicle's | | | | loss. |
| engine generators power. During the 4-stroke | | | | Most motorists will not have use for a traditional |
| process, the fuel within the chamber is ignited by the | | | | HEMI engine given their other options (for example, a |
| spark plug. It burns and produces energy. The hotter | | | | newer pentroof design). That said, it's impossible to |
| the fuel is, the more efficiently it burns. Because of | | | | ignore the impact the HEMI has had upon the |
| its design, a HEMI has less surface area than a | | | | automotive industry. |
| conventional flat head engine. That means the fuel | | | | |