In 2015 we (Concours Sportscar Restoration) set about building a tribute to the famous period racing car of the early 1950’s, the Flag Blue metallic XK120 roadster LXO126 as raced by the legendary Scottish race team, Ecurie Ecosse. Gavin wanted the car to look very much the same and wanted to include a lot of the distinguishing features that add to the charm of the car, without being tempted to modernise or upgrade the car too much. He wanted a very strong engine but one that is easy to drive and live with and one that looked period correct under the bonnet.
Basically, a lighter, more powerful version of the car from the day that looked just like it!

Chassis:
The original XK120 convertible chassis (677586) was a bare chassis that we acquired from a colleague in Queensland in 2015. We repaired some minor rust, but it was a good, sound chassis. Painted satin black two pack.

Body:
The body is an all new body made from aluminium, but in the shape and form of a steel bodied XK120 (as opposed to the early factory aluminium bodied XK120 roadsters that were alloy skinned over a wood ash frame). Deviations from standard include removal of the battery boxes behind the seats and deletion of the bumper bars, rear number plate plinth and fixed windscreens. Correct period aero screens with period wind deflectors are fitted, a new chrome grille, new taillight assemblies and correct new tripod XK120 headlamps.
The body is finished in the correct Ecurie Ecosse Scottish race team colour of Flag Blue metallic.

Engine:
The engine bottom end is a 3.8 unit originally from a MKII (LA9082-8) but is fitted with the correct XK120 sump. It features custom length (longer than standard) Arrow conrods and short custom JE forged pistons with total seal rings. The long rod/short piston combination delivers more torque than the standard combination. Compression ratio is 10.5:1. A late XJ Jaguar oil pump is used, mated to a remade larger version of the XK120 oil pickup to suit the sump. The whole bottom end has been balanced. ARP cylinder head studs and nuts are used.

We didn’t want to see a late (E Type) cylinder head nor did we want to use triple carburettors as we wanted the under bonnet to look a lot like the Ecurie Ecossie car. We used a correct early XK120/MKVII (D2237-7) A port cylinder head of the type used on the Ecurie Ecossie car, an XK inlet manifold and new sandcast 2 inch SU carburettors. The head was CNC ported and larger 1 7/8 inlet and 1 5/8 exhaust Rob Beere stainless valves were fitted with new lightweight followers and retainers. Custom billet Kelford cams were fitted with matched valve springs. The inlet manifold was port matched to the cylinder head and to the 2 inch carburettors. AFM gaskets are used throughout the engine and a Cometic head gasket is fitted. A new alloy bodied water pump is fitted and a 123 electronic ignition system (with adjustable advance curve) and an MSD ignition amplifier are fitted. The MSD unit is mounted under the centre of the dash and features and adjustable rev limiter (currently set at 6000rpm).

Long primary and short primary extractors were both tried on the engine dyno with the short primary system giving the best results.
Engine performance. The engine produces maximums of 285hp at 5900rpm and 283 ft/lbs of torque at 4200 rpm.
Compared to a standard, freshly overhauled XK120 engines that we have rebuilt and run on the same engine dyno which typically produce 195hp at 5000 rpm and 235 ft/lbs of torque at 3000 rpm.

Gearbox:
Gavin originally rebuilt an XK120 Moss gearbox for the car but decided to go to a 5 speed. Fitted is a brand new alloy cased gearbox specifically designed and cast to suit Jaguar 6 cylinder engines and transmission tunnels. Concours Sportscar Restoration has fitted dozens of these to cars ranging from otherwise standard, to E Type’s with 400hp. The gearbox uses the world renowned MT75 gearset as used in Ford Cosworth engineered cars and the ratios are almost identical to the standard gearbox ratios.
Fitted is an E Type bellhousing which allows the use of a hydraulic clutch. The flywheel is a new alloy E Type and the clutch is a 9.5in AP Racing diaphragm clutch. Apart from the overdrive 5 th gear, lighter weight and slick shifting, the other big advantage of using this gearbox as opposed to the original Moss gearbox, is the use of a hydraulic clutch. The original mechanical XK120 clutch was very heavy in operation.
A new heavy duty tailshaft was fabricated to suit and the clutch hydraulics are in the form of a Tilton master cylinder, E Type slave cylinder and a braided line.

Gearbox ratios:

Final Drive:
An XK150 differential assembly was used as it was Limited Slip and gave provision for the use of period disc brakes if ever fitted. The differential was fully rebuilt with a new 3.54 crown wheel and pinion fitted.

Suspension:
Original XK120 suspension arms and stub axle carriers were used with the suspension upgraded with new larger diameter 1.057” (standard 0.930”, SE 1.000”) front torsion bars and new larger diameter 0.875” (standard 0.6875) front sway bar. Poly bushes are used throughout. New stainless-steel stub axles are fitted. Externally adjustable GAZ front shock absorbers are fitted.
New uprated rear springs leaves were made and fitted and the rear shock absorber system converted from the original lever arm to XK140 telescopic shock absorbers (adjustable KONI shocks used).

Steering:
An original right-hand drive XK120 steering box is used with all correct right-hand drive steering link components, all totally reconditioned. Adjustable tie rods are fitted. An exact replica C Type steering wheel is fitted. That’s cool!

Brakes/Wheels/Tyres:
We fitted a Fosseway disc brake conversion to the front of the car featuring 4 piston alloy callipers.
The rear brakes are late XK120 self-adjusting drum brakes with all new components. The brake linings have been relined with a race compound. The hydraulics are controlled from the custom floor mounted pedal box using two Tilton master cylinders and an adjustable brake bias. Braided brake hoses are fitted.
The five roadwheels are original XK120 and drilled to remove brake heat as was a period modification performed back in the day, just like on LXO126, painted silver. The tyres are Vredestein 185HR15 radials.

Cooling/Fuel/Exhaust/Electrics:
An Alicool (UK) aluminium radiator is fitted with an integrated electric thermo fan, controlled by a Davies Craig adjustable fan controller (with LED temperature display).
A new aluminium fuel tank is installed with a period correct external quick fill fuel filler. A new, correct, negative earth square bodied SU fuel pump is fitted with braided lines from tank to carburettors. Fuel requirement is minimum 98 PULP.

The exhaust is full stainless mandrel bent Classic Fabs (Scotland) single to twin SE style system.
A new cotton braided writing loom is installed. The car has been converted to negative earth and a sealed Odyssey battery installed in the boot. A Dyna Lite alternator (generator lookalike) is fitted with a dummy period looking regulator with internal full system fusing. A gear reduction starter motor is also fitted. All new dash switches have been fitted and the original early XK120 instruments restored. The tachometer has been converted internally to operate electrically instead of by cable. A modern brake and reverse light switch have been incorporated into the brake pedal and gear lever assembly, respectively.

Interior:
The interior is finished in black leather to replicate LXO126. The seats are replica C Type bucket seats but fitted to new modern seat runners. A custom designed and made stainless steel pedal box assembly is fitted to give vastly improved control of the brake, clutch and throttle pedals whilst increasing legroom. The interior is basically trimmed as per a standard XK120 roadster.

General and Technical Specifications and Comparisons:

*measured between the ground and the centre of the front chassis crossmember
** with all fluids and 20 litres of fuel

The car has travelled a mere 500 miles since it was completed and has just been subject to a major service and check over, is ready for immediate use and offered for sale at $250,000

Car as featured in Retromotive magazine: