 Although the XJR-14's predecessor, the XJR-11, used a twin turbo-charged 3.5-litre engine derived from the Metro 6R4-derived JV6 engine, in order to comply with the new rules the two turbochargers would have needed to be removed.Naturally this wasn't a realistic option, nor was it ever considered, given the design compromises of not using a bespoke engine.But given the Jaguar-Ford connection, it was a decided to utilise the 3.5-litre Ford HB V8 Formula One power plant.