The XJ13, as originally envisaged by Malcolm Sayer and built in Jaguar's Competitions Department, is different in a number of respects from the rebuilt car which now graces Jaguar Heritage's collection.
Chief amongst these differences are the different wheels and treatment of the wheelarches.
The following animated image attempts to show how Sayer's classically elegant and timeless lines are emphasised in the original, 1966, car:
1966 XJ13 superimposed on the car as it is today
It may be argued that, although the present wheelarches and wheels give the car a more contemporary "aggressive" stance, perhaps something of the understated elegance of Sayer's design has been lost? One thing it does seem to have lost is the appearance of being "on the move" even when it is standing still. What do you think?
Whatever your views, the car was united with its first prototype engine in 1966 and (according to Peter Wilson) was originally shod with "Lightweight E-Type" wheels similar to these:
"Lightweight E-Type Alloy Wheel"
The following original drawing (shown courtesy of the Jaguar Daimler Heritage Trust) show how Sayer intended the car to look - complete with his treatment of the wheelarches.
Original XJ13 - © Jaguar Daimler Heritage Trust
In 1967 (as recorded in the XJ13 Log Book) extensive modifications were carried out to the body to accept different tyres. Some of these "extensive modifications" involved chopping out and reshaping the rear wheel arches (the fronts seem to have been largely untouched) and the fitment of the style of wheels as seen on the car today. Is it possible this was chosen as an easier option rather than modify the driveshafts/suspension etc? It seems perfectly possible to have fitted wider tyres and remain faithful to Sayer's original design?
The timing of the change fits in with extensive testing at Silverstone where both drivers reported issues with rear wheel grip/steering/feel. Was the fitment of wider tyres a knee-jerk reaction to this? Detailed investigations of the car after the Silverstone tests revealed that not only was the wrong rubber compound supplied by Dunlop, but an imminent driveshaft/bearing failure will have resulted in uncontrolled camber changes of the rear wheels during testing.
During the car's rebuild in 1972/73 the front wheelarches were widened to suit the rears and "eyebrows" were added all round. The reason for the "eyebrows" was given as "for cosmetic reasons" and for "stiffness".
There are many other differences between the 1966 car and the car we see today - some quite subtle and others much more obvious. As this project proceeds I shall continue to attempt to unearth the 1966 car ...