Ford Cortina GT500 The second tank.  Genius.


A model unique to Australia, the GT 500 was to be the car that took Ford to the top of the mountain at the Bathurst (formerly Armstrong) 500, hence the name. Something special had to be developed to mix it with the imported cars that were allowed for the first time in 1965. The Lotus-Cortina would have been more than adequate, but the elegibility rules required 250 be imported to qualify it, as opposed to the production of 100 cars to qualify a local model, so the GT 500 was born. The GT 500 was no Lotus-Cortina, but it certainly was a step up from the GT.

It was designed for Ford Australia by Ford's Works Team Manager, Harry Firth, wielding the spanners in his Queens Avenue workshop in Auburn, Melbourne. Starting with the GT's 1500, he added a new cam, reshaped the combustion chamber, raised the compression ratio to 9.5:1, modified the head further, lightened the flywheel, and fitted copper lead main and little end bearings for improved engine life at high revs, which was a good thing as the GT 500 was able to spin out to 7000rpm. He also stuck on a modified version of the GT's Weber carby. The chokes were enlarged a couple of mm each, up to 27 and 29 mm throats for primary and auxiliary respectively, with appropriate re-jetting, etc. (Thanks to Graham Leaver for this info.)

It had an 8.5 gallon aluminium auxiliary fuel tank that increased the fuel capacity to 17 gallons, with the two tanks interconnected, and fed through twin snap-on fuel caps, located behind the rear window. These twin fillers were the result of a bit of craftiness on Harry Firth's part, who realised that they would help reduce time spent by the car in the pits. This proved to give the GT 500 the advantage over the more nimble and zippy Mini Coopers, and was an idea that everybody pilfered for the 1966 race. With the GT 500, craftiness abounded. The car came with an air cleaner, but it wasn't fitted. Why? So it didn't have to be fitted for racing!

"It is probably the cheapest and easiest way to combine business and pleasure, and would be a good beginner's car in which to learn the basic rudiments of the sport." The water-catchers.

Large air scoops under the front bumper directed air to the front discs, which had no backing plates. The scoops also effectively collect water, which means a GT 500 is fun and games to drive in wet weather! The disc brakes used pads made from competition material, and wider wheels again were used. The GT 500 also featured a close-ratio gearbox used by Lotus (although originally a Ford effort) that was used in the Lotus Cortina and the twin-cam Escort. It used the following ratios: 1st 2.50 (GT 3.54), 2nd 1.64 (2.4), 3rd 1.23 (1.41), top 1:1, with the same 3.900:1 final drive ratio. All this improved the performance over the GT to 98 bhp at 6000 rpm, a top speed of 103.6 mph, and a standing quarter of 18.2 seconds ('Wheels' Apr. '66).

Article CORTINA GT 500 - David McKay tries the ultra high-performance GT 500
'Modern Motor', September 1965

The car was released in July 1965, and cost £1498, about £500 more than a basic Cortina. Only a 2 door was available, with fixed rear windows that didn't flip open as on the 220/240. Only 112 were produced, all between May and August, which sold like hotcakes. For years this has been the 'official' production number, but these days if you ask Harry Firth about it, he'll tell you that about another 185 were built, with a lot less regard to following specifications, so if yours has an odd combination of parts, perhaps that's why. They achieved their intended destiny in the 1965 race, finishing 1-2 in Class D, and 1-2 outright, ahead of a Mini Cooper S, with the winning car being driven by Barry 'Bo' Seton and Midge Bosworth (now there's a name). The success of the GT 500 led to elegibility rule changes for the 1966 race. In an attempt to eliminate 'homologation models', the minimum number of cars produced to qualify a local model was lifted to 250, a number too high to make limited production runs viable. At any rate, Ford were investing their racing energies in their new Falcon GT, a car which was to become legendary in Australian motoring history.

Article The 1965 Armstrong-winning car could easily have been cheated of certain victory. We tell how in our exclusive road test of... FORD'S FIERY 500
The Editor, 'Sports Car World', January 1966

As a rather bizarre footnote, I'd like to mention a small article in 'Sports Car World', January 1965. It seems that Harry Firth became so synonymous with Cortinas in Australia, that he was invited by the Mayor of the Italian city Cortina for a special celebration they were having there. I'm hoping that if I keep this page going long enough, I might get a similar invitation. And if you're reading this and you are the Mayor of Cortina, my Email address is Hope to hear from you soon.


Features & Specifications

As stated in document released by 'Advertising and Sales Promotion Department, Ford Sales Company of Australia Limited', July 1965

4 Cylinder OHV cast integrally with upper half of crankcase. Bore 3.187 ins., stroke 2.86 ins., capacity 1498 cc. Compression ratio 9.5:1. BHP 95 @ 6000 rpm. Push rod operated overhead valves with integral guides cast into fully machined cast iron ported and polished cylinder head, with special copper asbestos head gasket. Dynamically balanced 5 bearing cast iron crankshaft with integral weights running in new type steel back copper lead bearing liners. Lightened and balanced flywheel and clutch assembly together with a special crankshaft pulley of machined steel. Connecting rods and H-section forging with steel backed new type copper lead bearing liners. Special conrod bolts with enlarged bolt-head and and lock tabs. Camshaft ground to revised specification. Cast aluminium alloy inlet manifold and dual barrel down draught carburettor with revised chokes and jetting. 3-point rubber suspension of engine and gearbox.

Single dual barrel draught Weber with differential throttle opening. Modified choke, emulsion and jet sizes.

Engine Lubrication
Forced feed type, oil being circulated by am oil pipe mounted on the right hand side of the engine.

12 volt oil filled coil; distributor has automatic centrifugal advance and retard with additional vacuum control.

Fuel System
Diaphragm type fuel pump mechanically actuated by rocker arm and eccentric lobe on camshaft. Standard fuel tank of 8 1/4 gallons plus interconnecting auxilliary tank of 8 3/4 gallons. Quick fuel filling effected by two filler caps mounted on either side of the upper back panel.

Cooling System
Impellor assisted thermo-syphon with the water pump bolted to the front face of the cylinder block. Coolant flow is controlled by a restrictor (in lieu of a thermostat). Thermostat is supplied as a no-charge extra and should be used for touring purposes.

4-speed floor mounted remote control all synchromesh close ratio gear box with hydraulically operated dry, single clutch plate.

Ratios: 1st 2.50:1
2nd 1.64:1
3rd 1.23:1
4th 1.00:1
Reverse 2.80:1

Rear Axle
Semi floating pressed steel banjo housing with hypoid final drive. Axle ratio 3.90:1.

Front - Independent coil springs and double acting telescopic hydraulic shock absobers.
Rear - Longitudinal assymetric semi-elliptic leaf springs with radius arm. Hydraulic double acting telescopic shock absobers.

Front - Hydraulically operated disc brakes 9.5 ins. diam. x 0.375 ins. thick. Pad thickness 0.415 ins. Special competition brake pads along with special alloy air scoops.
Rear - Hydraulically operated drum brakes 9.0 ins. diam. x 1.75 ins. wide. Special competition brake linings.
Handbrake - Cable operated effective rear wheels.

High efficiency recirculatory ball type worm and nut steering gear with ratio of 13.4:1. Wheel 15.5 ins. diameter. Turning circle 33.75 ft. 3.2 turns lock to lock.

Electrical Equipment
Two brush generator used in conjunction with regulator. Starter motor, single tone horn, 12 volt battery 40 amp hr. at 20-hour rate. Two sealed beam headlights, parking lights and left and right turning indicator lights. Speedometer, tachometer, fuel gauge, temperature gauge, oil pressure gauge, ammeter.

Wheels and Tyres
Pressed steel with wide based rims. Tyres 5.60 x 13 ins. 4-ply tubeless; with tube, 165 x 13 radial.

2-door all steel welded integral body/frame chassis-less construction. Key operated lock on driver's door. Slight wrap around inclined windshield of toughened safety glass and a full width curved rear window. Full drop door windows with quarter vents incorporating locking catches. Laminated windshield available as an option.

Dimensions: Length 168.31 "
  Width 62.50 "
  Height 54.60 "
  Wheelbase 98.00 "
  Track - Front 50.00 "
  Track - Rear 49.50 "
  Clearance 6.40 "

Other Standard Equipment
Choice of 6 exterior colours, including 4 metallics
Choice of 2 interior trims
Dual padded sun visors
Padded dashboard and centre console
Glove compartment with lid
Front parcel tray and rear window shelf
Door and hand operated courtesy light
Pull armrests on both doors
Electric windshield wipers
Thick roof insulation
Foam padded individually adjustable front bucket seats
Rubber floor mats
Safety door locks
19 cubic feet boot with counter-balanced lid
Centre pillar mounted seat belt anchorages for lap/sash seat belts
Windshield washers
Aeroflow air extraction system
Instrument panel light switch
Air cleaner - supplied but not fitted


Change engine oil 1500 miles
Check fan belt adjustment 1500 miles
Change oil filter 3000 miles
Replace air-cleaner element (if fitted) 3000 miles

GT 500 Images

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