Simplify the following text for a Grade 7 native English-speaking person.
Original: The Cortina engine was also the basis for the FVA , a Formula Two engine introduced in 1966 .
Simplified: The Cortina engine was also the basis for the FVA , an F2 engine introduced in 1966 , and developed under the same contract as the DFV , for the new 1.6 litre engine rules .