The decision for the maximum displacement of just 1.5-liters for the engines in Formula One starting in 1961 would be a widely unpopular decision by the governing body. In the eyes of many, the decision would make no difference between Formula One and Formula 2. And, in 1964, Cooper would demonstrate just how true this belief really was by building a car capable of being used in either series and that was practically indistinguishable for the exception of the chassis notation.
Toward the later-part of the 1950s, Cooper was quickly becoming the team to beat in Formula One. Aided by the driving and engineering talents of Jack Brabham and Bruce McLaren, Cooper Car Company would go on to set the Formula One and motor racing world ablaze with its mid-engined chassis. The mid-engine revolution in motor racing would truly begin in earnest.
However, at the time Cooper unveiled its mid-engined T51 marvel, there was really nothing else that could compete with it and the thinking was still directed toward front-engined chassis design. Therefore, this advantage would allow Jack Brabham to take back-to-back World Championships in 1959 and 1960.
The regulations to limit engine capacity to 1.5-liters and to contain speeds would be announced even before the Cooper T51 even took its first victory a couple of months later. However, the new regulations seemed entirely aimed at the light, nimble and compact mid-engined cars that would come to dominate the Formula One landscape by the beginning of the 1961 season.
At the time the decision would be announced in London, the British manufacturers like Vandervell and others would believe the rules were squarely aimed at their new-found success. This would be understandable given that British manufacturers long trailed those from Germany and Italy throughout most of the first decade of the new Formula One series. The decision would seem to be a move by the FIA to 'gang-up' on the British marques. It was also believed that making the new Formula One regulations the same as the current Formula 2 regulations would take away from the spectacle that Formula One was to be.
As a result of the announcement many of the teams, especially the British ones would try and defy the regulations by not creating and designing cars fitting to the upcoming regulations. The British teams would try to offer alternatives and to stall, but the majority of the nations agreed with the new regulations and would leave British teams, like Cooper, on the back foot heading into the 1961 season.
Ferrari would resume its place of prominence in Formula One while the British teams would be sent scattering trying to catch up. This move by the FIA, and the subsequent stalling tactics by the British would end up hurting Cooper. They would go from back-to-back world champions to fighting hard just to finish and finish in the points.
Things would turn around for the team when it ran its T55 and T60s throughout the 1962 season. In the hands of Bruce McLaren, the team would manage a victory at the Monaco Grand Prix and a 3rd place finish in the championship.
The T60 would lead to the T66 for the 1963 season. Heading into the season the Cooper team had high hopes for the T66, especially considering the success the team had enjoyed the year before. McLaren would earn no less than three podium finishes and, with the help of Tony Maggs, would help the team to earn 25 points over the course of the season. However, the team would slip down to 5th in the standings by the end of the year.
In the eyes of many, the change in regulations heading into 1961 would be seen as a step backward. And, in fact, there would be absolutely no difference in the maximum displacement allowed between Formula One and Formula 2 when the Cooper Car Company was looking forward to the 1964 season. Therefore, the team would be hard at work designing its new chassis, but a chassis that would be able to be used in both Formula One and Formula 2.
The design team at Cooper would receive news back from Bruce McLaren following his winter spent driving a 'slimline' Cooper in the Tasman series in Australia and New Zealand. Much of the car's design in which he had been using in the season had been derived from the T70 Formula 2 car. Therefore, the designers and engineers would straight-away adapt and incorporate some of those features in a new Formula 2 car, the T71. They would also be used for a Formula One chassis that would become known as the T73.
All Coopers of the period were built relatively the same. The basic chassis frame would come from four, large diameter tubes and a minimal amount of triangulation for stiffness. In fact, the main source of stiffness on the T71 would actually come from the steel sheet attached to the underside and up around the lower sides of the main part of the chassis.
The incredibly tight and compact width of the car would come as a result of the elimination of the pannier tanks. However, the driver still would find himself seated between a couple of tanks of highly-flammable fuel.
Up at the nose of the car, the tight, low-profile radiator opening would actually accentuate the overall small size of the car as it would practically be all that would be seen from head on. The radiator would be positioned in an upright stance within the nose and the pipes leading the water and oil to and from the nose can be easily seen protruding out from the lower sides of the car.
The front suspension of the car would see Cooper break with tradition. More and more teams were beginning to use rocker arm-type front suspensions. This allowed the whole coil spring assembly to be hidden within the car's bodywork. Because of the small size of the car Cooper wouldn't be able to totally hide the coil springs but it would still follow the same pattern. Girling disc brakes would be standard and mounted outboard on all four wheels.
The only real difference between the T71 and the Formula One T73 versions would be the engine sitting behind the driver. The Formula One version would still be just 1.5-liters in displacement but would be a V8 Coventry Climax FWMV engine. The Formula 2 T71 would sport a twin-cam, 4-cylinder engine.
Though built to compete in Formula 2, a T71 would be entered in the British Grand Prix under Gerard Racing. It would use a 4-cylinder Lotus-Ford twin-cam engine and would be driven by John Taylor.
Although the car would be going up against other 1.5-liter machines, they would sport more cylinders and would be more highly-tuned than the Gerard Racing entry. Nevertheless, the T71/73 hybrid would go on to finish the race 14th, albeit some 24 laps down to eventual winner Jim Clark in a Lotus 25.Sources:
'Constructors: Cooper Car Company', (http://www.grandprix.com/gpe/con-coope.html). GrandPrix.com. http://www.grandprix.com/gpe/con-coope.html. Retrieved 23 January 2013.
Whitelock, Mark. '1.5-Liter Grand Prix Racing 1961-1968', (http://books.google.com/books?id=7E1vWo1JPJAC&pg=PA220&lpg=PA220&dq=cooper+t-73+Ford&source=bl&ots=ZO8YsCS7_g&sig=htNO9bJGzF0Qe0b8JkTPKmGT5Ck&hl=en&sa=X&ei=qdoOUOOqFeq90QGWpoGAAg&ved=0CFcQ6AEwBA#v=onepage&q=cooper%20t-73%20Ford&f=false). Google Books. http://books.google.com/books?id=7E1vWo1JPJAC&pg=PA220&lpg=PA220&dq=cooper+t-73+Ford&source=bl&ots=ZO8YsCS7_g&sig=htNO9bJGzF0Qe0b8JkTPKmGT5Ck&hl=en&sa=X&ei=qdoOUOOqFeq90QGWpoGAAg&ved=0CFcQ6AEwBA#v=onepage&q=cooper%20t-73%20Ford&f=false. Retrieved 23 January 2013.
'1964 World Drivers Championship', (http://www.silhouet.com/motorsport/archive/f1/1964/f164.html). 1964 World Drivers Championship. http://www.silhouet.com/motorsport/archive/f1/1964/f164.html. Retrieved 23 January 2013.
'Cooper-Climax: Home', (http://cooper-climax.com/). Cooper-Climax. http://cooper-climax.com/. Retrieved 23 January 2013.
Wikipedia contributors, 'Cooper Grand Prix results', Wikipedia, The Free Encyclopedia, 1 July 2012, 10:19 UTC, http://en.wikipedia.org/w/index.php?title=Cooper_Grand_Prix_results&oldid=500162306 accessed 24 January 2013By Jeremy McMullen