Iso Grifo - World Of Classic Cars - Rank 160

Iso Grifo IR8 Targa Conversion 1972

The Iso Grifo is an Italian automobile produced by Iso Rivolta between 1963 and 1974.

Beginnings

Iso S.p.A. in Bresso was already well known for producing the extremely well built and fast Iso Rivolta IR300; a sleek looking 2+2 Coupe based on a Chevrolet Corvette power train. After leaving Ferrari, in 1961 Giotto Bizzarrini set up “Prototipi Bizzarrini” in Livorno, Tuscany where he designed and consulted for marques like ATS, Lamborghini and Iso Rivolta. In 1963 he designed the Iso Grifo A3/L (L for Lusso {Italian for Luxury}) for Renzo Rivolta, who was looking for a follow-up to his Iso Rivolta GT. The body was designed by Giorgetto Giugiaro at Bertone, while Bizzarrini put his expertise in the mechanicals. Bizzarrini figured there would also be a demand for a race version of the Grifo and came up with the A3/C (C for Corsa) with a dramatic modified alloy body. He later dubbed it his “Improved GTO", as he had been the designer for the 250 GTO when he had worked for Ferrari. The engine was moved back about 40 centimetres (16 in), making the A3/C one of the first front-mid-engined cars ever built. To adjust the timing a piece of the dash was removed. Both cars were being built simultaneously. When leaving the factory both the 250 GTO and Iso Grifo originally fitted Pirelli Cinturato 205VR15 tyres (CN72).

Iso Grifo 7-Liter 1974

That same year Bertone showed the Grifo A3/L prototype at the Turin Auto Show, while Iso showed off the (partly unfinished) competition version; the Iso Grifo A3/C. Both were overwhelmingly successful. Although design changes had to be made to the prototype, Iso concentrated on getting the Grifo A3/L ready for production. The car got a light facelift that made it less aggressive but turned it into possibly the most elegant-looking Gran Turismo (GT) supercar ever produced. This “street” Iso Grifo GL received the fast, modified but reliable Chevrolet Corvette’s 327 V8 (5.4 L) engine—either in 300 or 350 hp—coupled to a Borg-Warner 4-speed toploader. These engines were ordered in the United States, but were completely taken apart and blueprinted before they were put in; as they did with the Iso Rivolta GT. With over 400 horsepower (300 kW) and a weight of less than 2,200 pounds (1,000 kg), the vehicle was able to reach speeds over 275 km/h (171 mph).

Iso Grifo Series I 1966

While Renzo Rivolta focused on the A3/L; Giotto tried to promote the A3/C—making for some tension between the two. This meant that the Grifo GL was being produced at Bresso and the A3/C at Piero Drogo’s Sports Cars of Modena under Giotto’s strict supervision. In 1964 the prototype Grifo A3/C raced at Le Mans (Edgar Berney/Pierre Noblet), running well until brake problems required a two hour pit stop. The car then resumed the race, finally finishing in 14th place; an encouraging result for a brand-new car. Only 22 examples of the Bizzarrini Grifo A3/C were constructed before a disagreement between Renzo and Bizzarrini ended the cooperation.

Parting Ways

Iso Grifo Coupe 1969

Finally in 1965 Giotto Bizzarrini and Renzo Rivolta split ways, which resulted in separate production of the street Grifo GL and the competition Bizzarrini A3/C. Giotto refined his A3/C and this eventually turned out to be his line of Bizzarrini 5300 Stradas and Corsas. From here on the “Grifo” name was lost in connection to Bizzarrini.

Bizzarrini continued to build both Bizzarrini Stradas and Corsas and had the alloy bodies (put together with more than 10,000 rivets) built by BBM of Modena. In 1966 he introduced a scaled-down version, the Bizzarrini 1900 “Europa,” first shown in 1967. Most of these cars got a tuned-up version of the Opel 1900 engine, some got Alfa Romeo engines. Only about 17 Europas were ever built, making it one of the rarest of his creations. Even rarer is the Barchetta version, the P538, with only three ever produced. A total of around 155 Bizzarrini Stradas and Corsas were built before Bizzarrini closes down in 1969 after a bankruptcy; all remaining parts and cars were sold off.

Production Begins

Iso Grifo GL 300 1967

The car developed 390 hp (290 kW) in its production form and could reach 110 km/h (68 mph) in first gear. Renzo Rivolta also showed a one-off Grifo A3/L Spyder at the Geneva auto show. The production of Iso Grifo GL started in 1965. In October 1966 the very first Grifo (car #97) with Targa Top was shown at Turin. This was one of 13 Series I Targas ever built; later, four series II Targas were built.

In 1968 the Grifo 7 Litri was introduced with a Chevrolet L71 big-block engine, a Tri-Power version of the 427 engine. This seven-liter power plant required changes to the car to fit, and a hood scoop was needed because of the engine's height. It produced 435 hp (324 kW) at 5800 rpm and the factory claimed it could reach a top speed of 300 km/h (186 mph). This particular 7 Litri is still lost.

Stylistic Changes

Iso Grifo GL 350 1966

In 1970 a styling change was made to the nose section of the car for the Grifo Series II. It got a sleeker look and hide-away headlights. In this new Series II, four Targas were built, and for the IR-9 "Can Am" version the engine was switched from the 427 engines to the newer 454 engine. Production stopped in 1972.

In 1972 Iso started to use small-block Ford Boss 351 engines; these cars (Grifo IR-8) can be recognized by their taller hood scoop. This was the final version of the Iso Grifos: Iso S.P.A. closed its doors in 1974 during the oil crisis.

Collectibility

Iso Grifo GL 1967

In total, 322 Series I and 78 Series II cars were built for a total of 413 Grifos, 90 of which 7 Litri. The rarest are the Series II 5-speeds (23 units) and the Series II Targa (4 units). All Grifos are desirable because of their rarity. A former employee of Iso, Roberto Negri, runs a small Company in Clusone, Italy, restoring Grifos.