Brabham BT19, the constructor driver wins the world title for the third time



The Brabham BT19 is the Formula 1 racing car designed by Ron Tauranac for the British team that bears the name of its founder, three-time world champion Jack Brabham, to participate in the 1966 and 1966 Formula 1 World Championships. 1967 and is the first car to win a world championship race bearing the name of the driver who drives it.


The BT19, also called Old Nail by its founder, was initially conceived in 1965 to house a Coventry Climax engine, but for the 1966 Formula 1 season, the International Automobile Federation decided to double the displacement limit to three liters. Climax therefore chooses not to develop some units with these specifications, forcing Brabham to use a new engine.


The Australian company Repco then developed a new eight-cylinder V-engine for Brabham in 1966, but a disagreement between the Australian driver and Tauranac, relating to the latter's role in the team, leaves no time to develop a new car, leading thus to the choice of adapting the ready-made frame of the BT19 to the new engine.


Technical analysis


The car, designed by Ron Tauranac, has a Repco-Brabham V8 620 engine with a power of 315 horsepower, strictly derived from that installed on the Oldsmobile F85.


Technologically speaking, the engine is made of light alloy, with the cylinder liners constructed of cast iron. The cylinder heads are of the cross-flow type with two valves per cylinder, with intake ducts on one side and exhaust ducts on the other, while the distribution is characterized by a single shaft with chain control. The crankshaft has cranks positioned on a single plane and wedge-shaped combustion chambers, while the structure in correspondence with the bench supports has a stiffening plate to ensure greater strength.


Specifically, Repco's 620 series engine is a normally aspirated unit, with eight cylinders in a V configuration. This one uses American engine blocks obtained from the Oldsmobile aluminium alloy 215 engine, which was abandoned by General Motors after several problems. of production in the early 1960s.


Repco mounts its cast iron cylinder liners in Oldsmobile blocks, stiffened with two Repco magnesium alloy castings and featuring cylinder heads with single overhead camshafts, driven by a chain.


The unit's interior consists of a custom-made Laystall crankshaft, Chevrolet (and, if necessary, Daimler) connecting rods, and specially cast pistons. The design of the cylinder head provides for the exit of the engine exhaust pipes on the outside of the block, passing through the spaceframe, before slipping inside the rear suspension.


The engine is water-cooled, with the radiators mounted near the nose of the car, for the best possible cooling. The 620 engine is decidedly light, weighing just 154 kilos compared to the 227 kilos of the Maserati V12, but producing only about 300 horsepower compared to the 330-360 horsepower produced by the powerful Ferrari and Maserati V12s. However, the powertrain features high levels of torque over a wide range of engine revs, from 3.500rpm up to a maximum torque of 316Nm at 6.500rpm.


The engine turns out to be less powerful than the performing twelve-cylinder Ferrari, but at the same time it can guarantee better power delivery and lower weight, increasing the overall handling of the car. In addition, it turns out to be easier to repair in the event of breakages and guarantees greater efficiency in terms of fuel consumption, which is found to be forty liters per hundred kilometers, while thanks to the use of economic components the engine requires decidedly low maintenance costs, with engine blocks available for eleven pounds each, and connecting rods at seven pounds each.


Repco delivers the first example of the new engine to the team's headquarters in the United Kingdom at the end of 1965, a few weeks before the South African Grand Prix which was to be held on January 1, 1966, a race not valid for the World Championship. Formula 1.


As previously described, there is no time to study a completely new frame, as a result Tauranac decides to use and modify the BT19 by building it around a mild steel spaceframe frame, similar to those used in its previous Brabham projects.


The use of a spatial structure turns out to be a very conservative design decision, given that in 1966 most of the competitors in the world use a lighter and more rigid monocoque design on paper, introduced in Formula 1 by Lotus during the 1962 season.


Tauranac believes that contemporary monocoques are usefully no more rigid than a well-designed spatial structure, and in addition they are more difficult to repair and maintain. The latter is a constant concern for Brabham, which is the largest manufacturer of customer racing cars in the world.


The company's reputation depends in part on the BRO, in fact the official work team, which uses the same technology as its customers, for whom ease of repair is an extremely important factor.


A slightly innovative feature is still used by Brabham with the introduction of oval section tubes around the passenger compartment, which in fact represents a weak part of the entire structure being a hole in the frame.


For a given cross-sectional area, the oval tube turns out to be stiffer in a defined direction than the round tube and Tauranac, which had a supply of oval tubes, uses them to stiffen the cockpit area.


Overall, the car weighs about 567 kilos, exceeding the minimum weight limit set by the regulations by 68 kilos, although it is still one of the lightest cars, while the starting weight of the race of a 1966 Brabham-Repco with driver and fuel on board it is about 642 kilos, 127 kilos less than the more powerful Cooper T81-Maserati rival. The bodywork of the BT19 is made of fiberglass reinforced plastic, finished in Brabham's usual racing colors: green with gold trim around the nose.


Although the science of aerodynamics did not greatly influence Formula 1 racing in the mid-1960s, Tauranac still uses the Motor Industry Research Association's wind tunnel to refine the shape of its cars, with Brabham attributing the nose facing the low and the raised rear lip of the bonnet as a special attention to aerodynamic details by Tauranac.

As for the suspension, however, the car has outboard suspension, with bulky springs and shock absorbers mounted in the space between the wheels and the body, where they interfere with the flow of air and increase unwanted drag.


Tauranac continues with this seemingly conservative approach, based on ongoing wind tunnel tests carried out in the early 1960s, which indicate that a much more complicated interior design would have provided only a two percent improvement in strength.


At the front, the suspension consists of double wishbones of unequal length and not parallel. The A-pillars, the solid components to which the wheels and brakes are mounted, are modified from the Alford & Alder units used on the British Triumph Herald sedan, while the rear suspension consists of a single upper link and features an inverted lower wishbone and two radial rods that position the uprights in molten magnesium alloy.


The wheels are initially prepared with a diameter of 13 inches, before being replaced with 15-inch tires, allowing the use of larger and more powerful brakes. Steel disc brakes are used on all four wheels and have a diameter of 11 inches for the 15-inch wheels, while for the 13-inch ones the brakes are 10.50 inches in diameter.


The engine is initially paired with a Hewland HD (Heavy Duty) gearbox, originally designed for the use of two-liter engines. The greater power of the three-liter Repco engine, however, turns out to be greater than that which the gearbox can reliably transmit when accelerating to full power from a standstill, with the result that Brabham normally makes very smooth starts to avoid any possible breakage of the gearbox.


The HD was later replaced with the more robust design called DG (Different Gearbox), produced at the request of the Anglo-American Racers team of Brabham and Dan Gurney, later becoming very popular among the various British manufacturers.


During the 1967 season, small fins are introduced on the nose to further reduce the lift acting at the front of the car, while the engine changes from the 620 specification to the 740 specification. Specifically, the 740 series unit uses - in the three races for which the car was entered in 1967 - a different, lighter engine block, also designed by Repco.


The cylinder heads are also redesigned, ensuring that its exhausts are mounted centrally and no longer pass through the spaceframe or rear suspension, unlike those of the 620 series, bringing power from the 300 horsepower of the previous specification to a total of 330. horses.


Season 1966


The BT19 is entrusted to Jack Brabham, Denny Hulme and Chris Irwin: this is the protagonist of a brilliant story, being brought to success almost entirely by the Australian driver. The BT19 also participates in several Formula 1 races not valid for the championship, prior to the start of the official 1966 season.


In fact, at the South African Grand Prix the BT19 is the only new car with a three-liter engine on the starting grid, setting the best time in the qualifying session before the race and leading most of the event before the race. fuel injection pump blocked.


Similar problems stopped the car on the second lap of the Syracuse Grand Prix in Sicily, but at the International Trophy, on the Silverstone circuit, Brabham again took pole position setting the new lap record and taking the victory ahead of John Surtees, on board of a Ferrari equipped with a three-liter engine.


The 1966 world championship officially opened with the Monaco Grand Prix, an occasion in which Brabham was forced to retire due to technical transmission problems.

At the next Belgian Grand Prix, at the Spa circuit, the Brabham came out unscathed from a huge slide at 215 km/h in the rain on the first lap. The rain forced several cars to retire and Jack Brabham, who has Goodyear tires not at all suitable for such extreme weather conditions, finished fourth out of five classified, while John Surtees won his last race in a Ferrari.


At the French Grand Prix, held on the high-speed circuit of Reims-Gueux, thanks to a shrewd management of the slipstream provided by Lorenzo Bandini, Brabham managed to take his first victory of the season, becoming the first man to win a race valid for the Formula 1 World Championship aboard one of its cars.


Although the first Brabham BT20, the definitive 1966 car, is available in Reims, Brabham instead continues to race with the BT19, using it to win the next three championship races.


The subsequent Grand Prix in Great Britain, which takes place on the narrow and winding Brands Hatch circuit, sees the Australian driver triumph again, struggling with a track made slippery by the oil spills left by the other cars, and by the light rain that fell on the track.


In Holland Jack Brabham returned to victory in conditions similar to those found a few weeks earlier in England, while on the occasion of the German Grand Prix, held at the Nürburgring Nordschleife, which the Australian defines Brands Hatch on steroids, he won his fourth victory after a heated duel in the rain with John Surtees' Cooper-Maserati.


In the following two Grands Prix in Italy and in the United States Brabham was forced to retire, while in the final race in Mexico the Australian driver won an excellent second place, which allowed him to conquer the third world title with a total of 42 points. Brabham uses the BT19 once again this season to get the pole position and victory in the Oulton Park Gold Cup.


At the same time, team mate Denny Hulme wins a second place in Great Britain, and three third places in France, Italy and Mexico, adding a total of 18 points which, added to the 42 obtained by the new World Champion, bring the Brabham in first position in the standings reserved for manufacturers, with a total of 60 championship points.

Season 1967


The BT19 is used again in three of the first four championship races in the 1967 Formula 1 season, debuting with the new Repco 740 engine at the Monaco Grand Prix, achieving pole position and a retirement, while Brabham finishes second in the Grand Prix of Holland.


The Brabham BT19 also competes in the final two races of the 1965-'66 Tasman Series in Australia, which follows pre-1961 Formula 1 regulations, including the 2.5-liter engine capacity limit.


Andrea Rasponi

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