Bizzarrini began his career by working with Alfa Romeo. His expertise and skills were quickly realized and his abilities were promising. Later in life, he began working for Ferrari where he was given the responsibility of development of the 250 GTO. Near the end of 1961, he left Ferrari and became a consultant driven by desires to build automobiles that would outdo his former employer. Lamborghini commissioned Bizzarrini to modify their V12 power-plant, an engine that would be used in future Lamborghini models.
After leaving Lamborghini, Bizzarrini was offered an opportunity by Renzo Rivolta, the owner of Iso, where he created the Iso Rivolta and the Grifo A3 models. The A3C was a GT race car powered by a Chevrolet Corvette engine that had been placed in the front but pushed back to take advantage of weight distribution. The car proved itself at the grueling 24 Hours of LeMans in 1964 where it emerged with a class victory.
By mid-1965, after thirty examples had been produced, the relationship began to disintegrated. Bizzarrini had placed his emblem on almost all of the A3/C models, rather than using Iso emblems. To make matters worse, Bizzarrini had trademarked the Grifo name. Bizzarrini had tried to increase the racing department's budget but was refused by Rivolta. Rivolta was disgruntled since Iso had provided funding to market and race the A3C's. The two companies decided to split, with Iso acquiring the rights to the Grifo name and Bizzarrini obtaining sole rights to build the A3/C and components and parts to construct a limited number of examples.
The A3/C was given a new name, the Bizzarrini 5300 GT. The vehicle was available in either Strada or Corsa trim, with the Strada being the more popular choice out of the two. The 5300 GT was basically the same as the A3/C. It retained the same chassis and under the hood lurked either a 365 hp or 405 hp engine, depending on the body-style. The main differences were cosmetic; the 5300 GT had aluminum bodywork by Carrozzeria BBM rather than using Drogo's Sports Cars of Modena. A bumper strip adorned the front of the vehicle and a few other aesthetic changes followed. There were no door handles; instead, there were push-button releases.
Three examples, all uniquely designed and created, were outfitted with Spyder bodies, one making its way to the 1966 Geneva Motorshow. The bodies were created of alloy and developed at Turin's Stile Italia under the supervision of Bizzarrini. The Spyder examples were dubbed 5300 SI Spyder and the alloy roof panel could be further converted into a Coupe or a Targa.
The Corsa version was a racing bred, the lightweight derivative of the 5300 GT. The bodywork was constructed of glass-fiber, the covers of the headlights were made of plastic, and a leather retaining strap kept the hood in place. The interior featured few amenities and whatever was not needed was removed. Modifications to the engine included polished ports and combustion chambers, free-flow exhaust system, high carbon connecting rods, and hot camshafts. The result was an 1190 kg dry weight automobile powered by a 405 hp engine.
As production progressed Bizzarrini started running short of components. To improvise, he constructed replacements or made changes to the original design. The seats, dash, and steering wheel were the most obvious of these changes.
Bizzarrini had created magnificent automobiles and designs and had done well at selling the examples produced but it was not enough. By the middle of 1968, his company went into receivership and finally being forced to close its doors in 1969.
by Dan Vaughan