1967 Ford GT40 Mark IV

The Mk IV was built around a reinforced J chassis powered by the same 7.0 L engine as the Mk II. Excluding the engine, gearbox, some suspension parts... more

by Peter Chilelli

Title

1967 Ford GT40 Mark IV

Artist

Peter Chilelli

Medium

Digital Art

Description

The Mk IV was built around a reinforced J chassis powered by the same 7.0 L engine as the Mk II. Excluding the engine, gearbox, some suspension parts and the brakes from the Mk.II, the Mk.IV was totally different from other GT40s, using a specific chassis and specific bodywork. It was undoubtedly the most radical and American variant of all the GT40's over the years. As a direct result of the Miles accident, the team installed a NASCAR-style steel-tube roll cage in the Mk.IV, which made it much safer, but the roll cage was so heavy that it negated most of the weight saving of the then-highly advanced, radically innovative honeycomb-panel construction. The Mk. IV had a long, streamlined shape, which gave it exceptional top speed, crucial to do well at Le Mans in those days (a circuit made up almost entirely of straights)- the race it was ultimately built for. A 2-speed automatic gearbox was tried, but during the extensive testing of the J-car in 1966 and 1967, it was decided that the 4-speed from the Mk.II would be retained. Dan Gurney often complained about the weight of the Mk.IV, since the car was 600 pounds (270 kg) heavier than the Ferrari 330 P4's. During practice at Le Mans in 1967, in an effort to preserve the highly stressed brakes, Gurney developed a strategy (also adopted by co-driver A.J. Foyt) of backing completely off the throttle several hundred yards before the approach to the Mulsanne hairpin and virtually coasting into the braking area. This technique saved the brakes, but the resulting increase in the car's recorded lap times during practice led to speculation within the Ford team that Gurney and Foyt, in an effort to compromise on chassis settings, had hopelessly "dialed out" their car. The car proved to be fastest in a straight line that year, thanks to its streamlined aerodynamics, achieveing 212 mph on the 3.6-mile Mulsanne Straight.

Uploaded

October 28th, 2018