Complex sentence: The two Porsche air cooled engines in each vehicle were replaced by two 300 hp Maybach HL 120 TRM engines powering two generators that drove two electric motors which in turn powered the drive sprockets.
Split into simpler sentences: The two Porsche air cooled engines in each vehicle were replaced by two 300 hp Maybach HL 120 TRM engines. They powered two generators that drove two electric motors which in turn powered the drive sprockets.