The Ferrari 121 LM was powered by a Lampredi designed, six-cylinder engine. The result was called the 306 and was used during the close of the 1954 season. The ‘306’ was really just a developmental version of what would come in the years that followed. The results were the Type 118 and Type 121. The Type 118 was a 3.7-liter engine and fitted into what became known as the 376 S. The Type 121 was a larger 4.4-liter unit, officially known as the 446 S, and it too powered Ferraris constructed by Scaglietti. The names of the 376 S and the 446 S were later changed to the 118 LM and the 121 LM. There were three versions of both constructed. One of the 118 LM was later modified to the 121 LM specifications.