requirements, together with FIA racing regulations and various government regulations governing car design and safety, influenced the overall design and engineering direction of the car. Concept car The FIA Group B regulations steered the concept towards a mid-engine, all-wheel-drive layout, with a Jaguar V12 engine as the power source. The concept car was designed and built at very little cost to Jaguar, as Randle called in favours from component suppliers and engineering companies he and Jaguar had worked with in the past. In return he offered public recognition for their assistance and dangled the possibility of future contracts from Jaguar. The name XJ220 was chosen as a continuation of the naming of the XK120, which referred to the top speed of the model in miles per hour. The concept car had a targeted top speed of so the name became XJ220. The XK120, like the XJ220, was an aluminium-bodied sports car and when launched was the fastest production car in the world. Engine and transmission Jaguar's engine designer Walter Hassan had previously developed a 48-valve variant of their V12 engine specifically for motorsport use. It featured a double overhead camshaft layout with four valves per cylinder, compared with the single overhead camshaft and two valves per cylinder of the production engine, which was used in the XJ and XJS models at the time. TWR had manufactured a number of these racing V12 engines during the 1980s and they had been raced competitively, with a 7-litre version of this engine featuring in the Le Mans-winning XJR-9. Five of these engines still existed, all of which were fitted with dry sump lubrication. One of five of these engines was chosen and considered to be especially useful as the dry sump would lower the vehicle's centre of gravity. The displacement of the V12 was set at 6.2 litres (6,222 cc) for the XJ220. The engine fitted to the XJ220 concept had titanium connecting rods. Jaguar had little experience with four-wheel drive systems at the time, having previously only produced rear-wheel drive cars. Randle approached Tony Rolt's company, FF Developments to design the transmission and four-wheel drive system for the XJ220, with Rolt's son Stuart running the project. Tony Rolt was the Technical Director of Ferguson Research, where he was heavily involved in the design of the four-wheel drive system used in the Jensen FF, the first sports car to be fitted with such