Jerry Booen has set about reconstructing probably the most significant car in Jaguar’s history: the Jaguar XKC 003.

This blog details the various stages of the reconstruction process.



Tuesday, 1 June 2010

Specification and Schedule

Jaguar C Type XKC003 Reproduction Specification and Schedule

Build Specification:
This car is being built to the original 1951 C Type Jaguar specification as a
replica of XKC003, the 1951 Le Mans winner and Mille Miglia entrant. It will
incorporate Jaguar works upgrades to 1952 level, most notably the prototype
Dunlop disc brake system.

All components will either be correct stock Jaguar XK120 original components
or newly manufactured parts made to original drawings and specifications.

Car to obtain FIA HTP certification.

Engine
Early spec 1951 XK120 engine fully reconditioned. Correct “A” series gas
flowed cylinder head with studless cam covers, siamesed spark plug wells, wide fan belt, 3/8” lift C Type
cams, twin SU H6 1¾ “ carburettors on XK120 manifold. 1¾” inlet valves, 1
5/8” exhausts. 9:1 pistons. Special two part wide eared aluminium cast sump.
Lightened flywheel. Gearbox: 1951 XK120 Moss gearbox.

Chassis
Tubular steel. Arc (stick) welded as original. Similar to the production C Type
frame apart from perforated swaged holes in the chassis floor cruciform. Minor
bracket and flange differences. Extra bolted flange fixings for the body
mounting along the bulkheads and floor to obtain extra structural stiffness
from the body. Chassis painted black.











Body
Body shape derived from Sayer’s original body data and drawings. Aluminium
hand formed by hammer and English wheel on a buck. No panel is identical to the standard C Type, it differs from production
C Type with
triangular bonnet
louvres, letter box
side bonnet louvres.
Headlamp apertures
were smaller (no side
lights) and trimmed
with an aluminium
bezel.
Body centre has steel bulkheads as
opposed to the production C type
aluminium. The steel bulkheads have a
horizontal swage running across the centre
and were fixed with a line of bolts to the
chassis to contribute to the structure.
The centre section has a bolt in passenger
door. For Le Mans it ran with a single aeroscreen (with no perspex) and at the Mille Miglia with a full width perspex screen and no aeroscreen. The rear view

mirror was cowled.































The rear body is similar to the production “C” type apart from the rear lamps mounted on the body surface as opposed to their own feature. The special nose badge has been cast in brass.


Interior
Similar to the production C but with a different gearbox cover (incorporating a wiggly gearbox breather) no Hardura trim covers, raised drivers heel floor, interior painted body colour rather than silver.
Light switch was early XK120. Seats were trimmed in green Rexine PVC. Longer pedals than standard with grooved pedal pads.
















Suspension
Standard early C Type suspension, Koni classic adjustable dampers, correct torsion bars. Front Suspension links are XK120 apart from special lower wishbones and steering arms. Back axle modified XK120. 3.54:1 axle ratio, no L.S.D. Early type Haynes anti-lift triangular upper axle link, no Panhard rod. Steering rack and pinion but with a special cast early type pinion housing. Wheels correct 54 spoke (D Type Developments) aluminium rimmed with Blockley tyres.

























Brakes
The prototype revolutionary Dunlop disc brakes were first fitted to XKC001 for development but first raced at Goodwood on XKC003 in 1952 (Moss 4th, fastest lap). The international debut of the disc brake was at the 1952 Mille Miglia (Moss Dewis). The car retired after crashing within 100 miles of the finish whilst in 3rd place.
These brakes differed from the later Dunlop discs by not having the distinctive separate piston housing and Plessey power system. They consist of 20 pads and pistons (6 pot fronts and 4 pot rear). Pads were circular (similar to the XK150). Each caliper piston fitted in its own cylinder, itself located in the main caliper bridge. To change the pads it was necessary to remove these cylinders withdrawing them past the circlip retention. All this necessitated rebleeding the system whenever the pads were changed.














Historically significant, this braking system is being researched to obtain maximum accuracy. Caliper internals have been designed using modern AP Racing seals for safety reasons. The caliper bridges will be cast while the pistons and cylinders billet machined.

Electrical

- Original style instruments

- Coil ignition with XK120 distributor

- Marchal headlamps (Le Mans regulation conformity, early 1950s)

- No sidelamps (dipped beams switch to low current)

- Twin SU fuel pumps

- Cotton braided loom

No comments:

Post a comment