Complex sentence: The other style of engine, known as the classic or square block models, were divided into four main types, the Featherweight or Forty Minus, the Forty Plus, the Century and the Century Plus.
Split into simpler sentences: The other style of engine, known as the classic or square block models were divided into 4 main types. The Featherweight or Forty Minus, the Forty Plus, the Century and the Century Plus.