Iso Grifo

The Iso Grifo is a 1964-1974 built by the Italian automobile manufacturer Iso Rivolta sports car. After the four-seat coupe Iso Rivolta IR 300 Iso presented in 1964, the conceptually similar but sportier two-seat Iso Grifo Coupe, a Gran Turismo for wealthy gentlemen drivers.

• 3.1 The car
• 3.2 racing applications 3.2.1 1964
• 3.2.2 1965

History of development

Instrumental in the development of the Grifo was an engineer Giotto Bizzarrini, a former Ferrari employees who had left the work of the Commendatore Ferrari in dispute and in 1963 opened his own design office in Livorno. Bizzarrini designed a platform frame with box girders, which - apart from a shortened to 20 inches wheelbase - the Iso Rivolta IR 300 the was similar. As drive American V8s were provided, first one derived from the Chevrolet Corvette 5.4 -liter V8 ( the same engine was offered in tamer version in the big Opel models). Other technology components were also to buy: The steering came from Burman, the limited slip differential of Salisbury, the Dunlop disc brakes, manually shifting transmission with five speeds from ZF Friedrichshafen, four-speed transmission of Mancie or Borg - Warner or a three -speed automatic transmission from Borg - Warner.

The design of the coupe drove in Iso Rivolta IR as was the case 300, Bertone; actually it was a work of the young Giorgio Giugiaro, Bertone had just previously appointed to chief designer. Giugiaro low, feline hatchback body with softly rounded, short-cut fenders and clearly recognizable, slightly sloping roll bar. At the low front we saw double round headlights. The rear end was marked by a large panoramic window, which passed into a trunk attachment, and tapering to the car towards completion considerably. Between the front wheel arches and the A-pillar large vents were provided, which were plated on some models. The principles of the designs date back to the Pininfarina Rondine I, a show car, which the Americans Tom Tjaarda had designed in 1963 on the technical basis of the Chevrolet Corvette.

The prototype of the Grifo was shown the end of 1963 at the Turin Motor Show under the name A3 / L ( Lusso ). His line already corresponded largely to the later series model; only the front section differed by oblique -level headlamps and a three-dimensional scale grille. Between the front wheel arch and the A-pillar is a striking vent that was covered with individual chrome struts and the view of an exhaust pipe located behind it in the style of American " side pipes " laid bare place. This design element was not taken into series production.

The L version was the road model. In addition, a lighter and stronger racing variant was planned, the Grifo A3 / C ( Competizione ). This model was launched in 1964 in the 24- hour race at Le Mans. The Belgian Pierre Noblet and the Swiss Edgar Berney drove the car to the 14th place overall and victory in the class for prototype 5 -liter displacement. The racing concept, however, was not pursued by Iso Rivolta. After a rift between CEO Rivolta and Bizzarrini A3 / C of Bizzarrini was built in-house and sold under the name Bizzarrini GT 5300 Strada ( as a street version) and Corsa ( an even sportier competition version with plastic body).

1965 began series production of the Grifo, which lasted until 1974. During this time there was a facelift: 1970 Rivolta changed the front end by folding headlights were introduced in the style of Iso Lele, the semi- concealed headlights at rest. Apart from these minor external changes Iso Rivolta offered in the course of time new engine options with different benefits. In these ( listed below ) details, it was, however, consistently to values ​​according to the SAE standard; the DIN values ​​are approximately 30 % below.

The basic model

The base model was first called Iso Grifo Lusso; later it received the additional designation IR 8 was offered over time with different American engines between 5.4 liters and 5.8 liters of displacement:

• Between 1965 and 1972, a 5.4 -liter eight-cylinder Chevrolet ( Chevrolet Turbo Fire) was provided as the standard engine, which should afford by different tuning measures 300-395 hp. The German trade journal Auto Motor und Sport examined a 1967 Iso Grifo 350 The vehicle reached a top speed test of 247 km / h and reach 100 km / h after just 6.4 seconds.

• Between 1970 and 1972 there was also a 5.7 ​​-liter version of the Chevrolet Turbo Fire with power 300-365 hp.

• During the year 1972 Iso turned over to Ford engines. Reasons is likely disagreements with General Motors for the payment of Chevrolet engines have been. The previous engine range was now history; for the Grifo there was 1972-1974 only a 5.8 -liter eight-cylinder Ford ( Cobrajet ) with 325 hp. The Borg - Warner automatic transmission was replaced with a Cruise -O -Matic by Ford in the same year.

Grifo Grifo Can Am and 7 Litri

In addition to these basic models offered Iso 1968-1972 to a much sportier version of the Grifo. This was resorted to each significantly larger engines from General Motors, which were more potent, but also heavier and required some changes to body, chassis and suspension. The era of big Grifo ended in 1972, changed as Iso his engine suppliers: the Big Block Ford engines that have been used for example in AC 428, held not entered the Grifo.

From 1968 to 1970 standing next to the base model of the Iso Grifo 7 Litri on offer, a sportier version of the Grifo with a much larger engine. For use was a 7.0 -liter version of the Turbo Fire - engine ( " Turbo - Jet" ) with 406 hp. The big engine made ​​for outstanding performance. Iso Rivolta was at a maximum speed of 300 Km / h. This value is probably too high; depending on the ratio of the rear axle up to 275 km / h were realistic. This, too, was of course still a value that brought the Grifo in the service areas of Ferrari and Lamborghini. The huge engine did not fit under the standard bonnet of the Grifo, so that a sweeping scoop - called the factory jargon "Penthouse" - had to be installed, which was the line of cars detrimental. The 7 Litri were indeed in view of inadequate heat dissipation thermally very problematic, although the iso standard oil sump of the Chevrolet " Turbo - Jet" against an enlarged, provided with additional cooling fins, aluminum version had changed. At higher speeds, the motor and cooling water heated to still strong; there have been repeated burst of engines. The German importer Auto Becker in Dusseldorf had in his workshop temporarily reserved a department that dealt with the rapid replacement of the engines of the Grifo 7 Litri.

• The successor of the 7 Litri was the Grifo Can Am. He was offered 1970-1972 and was now powered by a 7.4 -liter version of the Turbo Fire engine. Again, the maximum power is specified with 406 hp. The Can Am had as well as the 7 Litri to a " penthouse " on the hood.

Karosserievarianten

• The Iso Grifo was sold predominantly as a closed two-seat coupe with a hatchback body. Several cars had a steel roof, single were fitted to customer with a folding roof.

• Between 1966 and 1970, 17 were made with a Grifo Targa body. The vehicle remained unchanged with the exception of the removable roof panel ( between the window frame and roll bar ).

• Even before the start of series production Bertone presented in January 1964 a Spyder based on the Iso Grifo before. Apart from the roof section corresponded to the vehicle except for a few details later coupe, especially the front end was already on series level. The very elegant vehicle was not designed for series production; it remained in a single piece, which still exists today.

The production figures

Between 1965 and 1974 a total of 412 Iso Grifo were made, 17 of them as Targa. The 7 Litri version was produced in 70 copies, the Cam -Am version in 20 copies. From the late Grifo with Ford engines, there were about 25 copies.

Specifications

The Iso A3 / C ( Competizione ) is a specific for the racing version of the Grifo. Its design dates back to Giotto Bizzarrini, who was of the view that the sale of a road vehicle could be promoted through a successful racing competition version. It was produced until 1965 in about 30 copies in Bizzarrini Livorno and in any case partly marketed under the name Iso and reported in racing events. After Renzo Rivolta and Giotto Bizzarrini had separated in the summer of 1965 in the dispute, put Bizzarrini production of the sports car without major technical or formal changes in their own name on. The car was offered then until 1968 under the name Bizzarrini GT 5300.

The car

Developed in 1963 by Giotto Bizzarrini Iso A3 / C was an independent body, but the A3 / L similar chassis and the same drive technology.

The design of the sports car's body is usually Giorgio Giugiaro and Bertone thus attributed, while other sources the design on Giotto Bizzarrini itself and to its employees Piero Vanni lead back .. The body was usually made ​​of aluminum; it was made up in 1965 by Piero Drogo's Carrozzeria Sports Cars in Modena. An exception was the car built in March 1965 with the chassis number B 0222, which received a plastic body for the purpose of weight reduction.

The engine of the A3 / C came as in the case of the A3 / L of the Chevrolet Corvette, but had been revised in detail. The performance was given in the basic version with about 365 hp; by further processing, which mainly include the installation of four twin carburettors type 42 DCOE Weber was, the power was increased to 400-405 hp, according to other sources even 420 hp.

A special feature of the A3 / C was the location of the engine. In an effort to the weight as central as possible to arrange in the center of the vehicle, Bizzarrini positioned the heavy American engine far behind the front axle and thus realized a front mid-engine position. They meant that parts of the engine - including the distributor - were accessible only through the passenger compartment. You could be achieved via a flap in the dashboard.

While Renzo Rivolta did produce the street version Iso A3 / L at Bertone, the A3 / L was established in Bizzarrini Livorno. How many Iso A3 / C were prepared up to the separation of Rivolta and Bizzarrini, is not clear. The information in the literature are very inconsistent in detail; part is of 22 cars completed the speech, partly out of 30

Racing applications

The racing history of the A3 / C, although it is on closer inspection negotiated with him a model of the brand Iso Rivolta, closely associated with Giotto Bizzarrini, his company Prototipi Bizzarrini and the Bizzarrini GT 5300. Bizzarrini in charge of the racing and the A3 / C from the beginning on their own responsibility and nabelte across the path of motorsport by Renzo Rivolta increasingly from.

Even before the A3 / L " Grifo " was developed for serial production, the sports version A3 / C came on at the first international competitions. According to an agreement with Renzo Rivolta, who largely financed the race, the cars were mostly referred to the summer of 1965 as Iso A3 / C. For the first few times the cars were still reported by private drivers; from the summer of 1964 carried the messages then mostly by Giotto Bizzarrini, Bizzarrini Iso Bizzarrini Automobili or Prototipi.

1964

The first race at which an Iso A3 / C took part, was the 12 - hour race at Sebring in 1964. Riders were the Americans William McLaughlin, Enus Wilson and Ed Hugus. The team used the A3 / C one with the chassis number B0202 and looked after it had started the race from 29th place from 39th to the checkered flag.

A particularly prestigious success achieved in the spring of 1964, the newly established A3 / C with the chassis number B0207 in the 24- hour race at Le Mans. Reported by Bizzarrinis French representation, Société Sonauto, which was headed by Auguste Veuillet, the Belgian Pierre Noblet and the Swiss Edgar Berney drove to 14th place overall and victory in the class for unlimited prototypes. At six weeks later held a 12-hour race at Reims did not consider the B0207, by contrast; Noblet and Berney had to give up at half-time engine damage. During the year, still joined several other forces in European mountain - and long-distance races, most of which were denied by the B0207 from Noblet and Berney, while the B0202 has been used with some success in American events.

1965

Giotto Bizzarrini and Renzo Rivolta hoped to retract in 1965 further success in the long-distance race of the year. For the new season Bizzarrini built two new vehicles ( chassis numbers B0210 and B0214 ), corresponding to the last year's models substantially. Both vehicles were, however, already at their first use, the 12 - hour race at Sebring, destroyed, as Silvio Moser ( B 0210 ) and Mike Gammino (B 0214 ) and in each case after a failure of the brakes in their cars on a wall a bounced bridge.

For the following race, therefore, the B0207 used in the previous year had to be reported again; also built Bizzarrini his first car with plastic body on ( VIN B 0222 ).

In April 1965, achieved Pierre Noblet and Mario Casoni particular success when they were fifth overall with the old B0207 in the 1000-kilometer race at Monza and doing all Ferrari 250 GTO models could leave behind. Antonio Finiguerra and Régis Fraissant came 13th place in the new B0222.

Bizzarrinis main focus was in 1965 again on the 24 - hour race at Le Mans. Initially, Bizzarrini had provided the reporting of three A3/C-Fahrzeugen; but ultimately could only be the use of a vehicle - with plastic body of the B0222 - realize. Giotto Bizzarrini transferred the car by hand from Livorno to Le Mans. In the race of reported Iso Bizzarrini Prototipi car of Jean de Morte Mart and Régis Fraissinet was driven. They came as a total - Ninth reached the finish line as in the previous class victory.

In the following 12 - hour race at Reims Iso Grifo Prototipi reported two Iso A3 / C; both cars dropped out because of technical failure. A final factory employment took place at the 200 - mile race in Zeltweg, in which Chris Amon with the B0222 fourth. From the following year organized the Bizzarrini racing applications independently. The vehicles reported were called now Bizzarrini GT Strada 5300 and GT Corsa 5300th However, its use soon moved into the background because Bizzarrini its new model, the P 538S, increasingly preferred.

In 1991, Piero Rivolta ago, the son of company founder Renzo Rivolta, a new vehicle, the name of the Iso Grifo was 90. It was a developed in Italy by Dallara prototype, with the Rivolta wanted to test the public's interest in a revival of the brand Iso. Unlike most other super sports cars of that time such as the Ferrari Testarossa and the Lamborghini Diablo Piero Rivolta sat for a new car again on a classic front-engine design, which should consciously evoke memories of the concept of the former Iso Grifo. This approach also corresponded to the choice of drive technology: As the classic Grifo also used the Grifo 90 a motor from the Chevrolet Corvette, in this case, the most powerful engine of the Corvette ZR -1. The 5.7 -liter engine should make 440 hp, which were delivered via a six-speed gearbox to the rear axle. The bodywork was designed by Marcello Gandini; it consisted of plastic. The drag coefficient was reported to be 0.31, top speed 299 km / h

In 1991, a single, yellow painted prototype, which was shown in the following years on various exhibitions originated. Allegedly planned Piero Rivolta the start of series production for the year 1993. It was nothing. The car was not designed for series production; No other vehicle was built. One of the reasons may have been the height of the contemplated purchase price, which amounted to 100,000 British pounds and kept the public's interest in borders.