Below are some pictures showing the development of ADO71 – or Diablo, as it was known in the early stages.
One of the first “Diablo” concept pictures, as penned by Harris Mann. The Princess character is already abundantly clear.
Two-door scheme never made it into production… (Picture: BMIHT)
By August 1970, the first full-size clay model is finished – and it shows remarkable similarities to Mann’s early sketch (above). Contrast this with the final clay model of November 1970, shown below.
Not a glamourous picture this, but it shows the ADO71 undergoing wind-tunnel testing at MIRA (Motor Industry Research Association) in Nuneaton. This is actually a one-third scale model and demonstrates that the air flow over this model was pretty good for its day. Drag co-efficient was Cd0.404 (compared with 0.44 for a Ford Cortina Mark IV).
What do you get when you cross a coke-bottle design with a wedge? This proposal for a three-box saloon was ruled out early in the car’s development, with Saab and Rover P8 overtones. (Picture: John Capon)
Despite the fact that the new Leyland management charged their BMC forebears with excessively resorting to badge-engineering, they planned for their upcoming “D” sector car to be available in Austin, Morris and Wolseley forms. (Pictures: John Capon)
Many frontal treatments were tried… (Picture: BMIHT)
What’s this Project Delta? (Picture: BMIHT)
Trapezoidal headlamps coming through… (Picture: BMIHT)
If only… (Picture: BMIHT)