HEMI stands for Hemispherical combustion chambers, referring to the semi-spherical shape of the combustion chamber. This engine design effectively improves intake efficiency. In the mid-1930s, Chrysler engineers began developing the "FirePower" V8 engine, which at the time was only used in foreign-made racing cars. However, Chrysler engineers succeeded in implementing this technology in production vehicles.
Due to the semi-spherical combustion chamber design, the valves can be located within the cylinder head, and the valve area is increased. To fully leverage the advantages of high intake efficiency, each cylinder uses two spark plugs to ensure sufficient ignition energy.
The HEMI engine, produced to this day, is continuously being improved. In the context of global automotive companies advocating for energy efficiency and environmental friendliness, Chrysler has incorporated the Multi-Displacement System (MDS) into this engine. It can deactivate four cylinders during cruising, effectively addressing fuel economy concerns while maintaining performance. The HEMI V8 5.7L engine found in the Grand Cherokee produces a maximum power of 259 kW (352 PS) and a maximum torque of 520 Nm. The high-performance Grand Cherokee SRT8 is equipped with the HEMI V8 6.4L engine, delivering a maximum power of 344 kW (468 PS) and a maximum torque of 624 Nm.
As a former member of the Global Top Ten Engines, the HEMI engine is a source of pride for Chrysler. It is used in various Chrysler models, including the Chrysler 300C, Grand Cherokee, Dodge Charger, and others.
