In 1984, the only engine still being used under the 3.0 litre naturally-aspirated regulations was the 'Cosworth - DFV' and variants. A design that dates back to 1967 and had been developed over 18 years at the start of this documentary. The 'Cosworth - DFV' was so successful that in its lifetime, the engine had been used by various teams and had won 155 Grand-Prix's. It was modified extensively and became the 'Cosworth DFY' used for two more seasons in 1984 & 1985, making its total 'Formula One' lifetime of 19 seasons.
The successor to the 3.0 litre 'Cosworth -DFV' was going to be a modified 'Cosworth - BDA' (in-line 4 cylinder) to the 1.5 litre regulations, but this ended up being more problematic than predicted. Subsequently, a new 'Cosworth - GBA' (V6 cylinder) 1.5 litre engine was designed, built and tested for racing later, originally for the 1985 season but delayed to 1986.