Chrysler applied their military experience with the hemispherical combustion chamber to their first overhead-valve V8 engine, released under the name FirePower, not "Hemi," in 1950 for the 1951 model year. The first version of the FirePower engine had a displacement of and produced . Eventually, three of the four Chrysler divisions had their own version of the FirePower engine, with different displacements and designations, and having almost no parts in common. This lack of commonality was due in part to the three engine versions using different bore pitches (the center-to-center distance between adjacent cylinders). Chrysler and Imperial called their versions the "FirePower". DeSoto called theirs the "FireDome". Dodge had a smaller version, known as the "Red Ram". Only Plymouth did not have a version, but retained the Dodge poly-head engines. There was no Plymouth hemi engine until 1964.