A Short History of the Ford GT 40
The idea for the GT40 Mark IV came from the
Advanced Concepts Department of Ford's Special
Vehicles facility in Michigan in late 1965. The main
concept was to be the use of the lightest structural
technique then known, aluminium honeycomb.
While Kar Kraft worked to combine these feature
with the basic GT40 structure other designers
worked on an advanced body configuration. From
this came the 'J-car', but it's automatic transmission
was a big problem, as was the 'advanced
aerodynamics'. Revisions were made but they were
not yet up to scratch and Ken Miles was killed when
testing one in August 1966. Despite an intensive
investigation the cause was not pinpointed but the
aerodynamic problems were suspected.
The new body shape was completed just weeks before the 1967 Sebring race, and the engine was now putting out a lazy 500 bhp at 5000 rpm. The Mark IV was immediately successful winning the Sebring race in the hands of Bruce McLaren and Mario Andretti.
At Le Mans 1967 four Mark IVs three Mark II's and three Mark I, 302 powered cars contested. The winner was the
A.J.Foyt/Dan Gurney Mark IV with the McLaren/Donohue Mark IV 4th. None of the other GT40s finished. The
Mark IVs were clocked at 354km/h (220mph) down Mulsanne Straight and the 24 hours was covered at an average speed of 218 km/h (135.5mph). Fastest lap was at an average of 238 km/h (147.9mph), 30km/h faster than the record in1963 when Ford decided to go to Le Mans.
This then brought us to 1968...............
Specification GT40 Mk IV
- Engine: water cooled, 90 deg V8
- Bore: 107.5 mm / 4.24 in
- Stroke: 96.1 mm / 3.78 in
- Capacity: 6997 cc / 427 cu in
- Valves: overhead
- Compression ratio: 10.5:1
- Carburettors: 2 x 4bbl Holley
- Lubrication: dry sump
- Max. power: 375 kW / 500 bhp at 5000rpm
- Max. torque: 470 lb/ft at 5000rpm
- Clutch: Long 2 dry plate
- Gearbox: Ford T44 4-speed synchro t/axle
- Ratios: 2.22 / 1.43 / 1.19 / 1.00 : 1
- Final drive: Le Mans/Std 2.77:1/3.09:1
- Chassis: Shell of 12.7 or 25.4mm (½ or 1inch) thick expanded aluminium
honeycomb
- Body Panels: fibreglass
- Front suspension: independent, double wishbones, coilover shocks, anti
roll bar
- Rear suspesion: double trailing arms, transverse top link and lower wishbone,
coil over shocks, anti roll bar
- Steering rack and pinion
- Wheels 8 x 15 (f); 12 x 15 (r)
- Brakes Ford 11.5in vent. disc (f/r)
- Wheelbase 2413mm / 95in
- Track (front and rear) 1397mm / 55in
- Overall length 4343mm / 14ft 3in
- Width 1791mm / 70.5in
- Height 978mm / 38.5in
- Fuel 154l / 41 US gal / 34 imp gal
- Dry weight 1000kg / 2205lb
- Max. speed 354km/h (220mph)