Abarth Doppia Bolla - I dettagli. Part 1

Carlo Abarth’s company, founded in 1949 following the collapse of the Cisitalia team he had been managing, grew steadily in its first six years of existence.  From its initial office in Bologna, its operational base was swiftly relocated to Via Trecate, Turin.  At the outset, the main focus of effort was in upgrading and running the Cisitalia 204A roadsters and this was largely successful.  There was however quite a setback as autumn set in, when the Madrid Grand Prix went badly for the team.  But this served to reinforce the view Carlo had for some time held – that reliance on racing as a primary activity could be commercially ill-advised, there being too many extraneous influencing factors involved.  So, seeking to ensure that his new enterprise would be financially sound – and thus be able to fund its ongoing competitive involvement in motor sport – he began to apply both his business acumen and his engineering expertise to the development of automotive ‘accessory’ products targeted at consumers wishing to upgrade the performance of their cars.

Abarth was highly adept and energetic in identifying specific ‘needs,’ designing relevant component kits and marketing them effectively.  Recognising the large market opportunity represented by the number of Fiat-owners in Italy, the early products included an improved gear shift lever and uprated water pump.  The most significant addition to the Abarth catalogue however soon proved to be exhaust pipes/silencers, with improved intake manifolds then following – the exhausts made cars like the Fiat 500 sound sporty, while the manifolds could make them actually faster!  The success of such a simple but effective ‘recipe’ was confirmed by steadily increasing sales, such that additional factory capacity was necessary by 1954 when a secondary premises was taken over at Via Pacchiotti in order to make the kits which had come to be characterised under a ‘brand,’ autotelaio e motore per Fiat 600 derivazione Abarth 750.  At the same time, with a long term vision, Abarth was hard at work to establish a potentially grander scale/high profit business strand – the production of special/modified complete vehicles with an emphasis on high performance, distinctive style and exclusivity.  Thus, there was a series of attention-grabbing sports car collaborations which raised the recognition and reputation of the Abarth marque:  In 1952, the Abarth 1500 – Fiat 1400-based, with a striking Bertone coupe body, styled by Franco Scaglione; the following year, with classy Ghia two-seater bodywork, Abarth’s version of the new 1100-103 not only looked good and futuristic, but also boasted nearly twice the horsepower of the standard Fiat product on which it was based; also in 1953, Abarth created a modular-construction body for the Ferrari 166 MM.  Ultra lightweight, this was another extremely good-looking vehicle, but in this instance the focus was on functionality in motorsport terms; 1954 saw Abarth turning to Alfa Romeo for the next style-and-speed project.  Based on the Portello-made 1900 Super, the Abarth-Alfa Romeo 2000’s Ghia-designed lightweight aluminium body combined with engine modifications giving a power output of 135 bhp resulted in another stylish, real high performance coupe; at the end of that year, reverting to the Fiat 1100-103, Abarth struck up a working relationship with Mario Boano’s carrozzeria, working to styling designs by Michelotti, to create three highly elegant sports cars – the racing 207A, two-seater barchetta 208A and the 209A coupe; Boano became further involved that same year when Abarth was commissioned by Alfa Romeo to build a new Prototype racer utilising a 1500 cc version of the Giulietta’s twin cam engine – the resulting 750 Competizione did not get beyond the prototype stage, but was yet another exciting example of Abarth’s expertise in designing/developing such vehicles.

It was not surprising therefore that Carlo Abarth was ready to capitalise on the business’s learnings from this sequence of special projects.  His ambition was to find a partner and related synergies in order to produce higher value cars in volumes that would in turn boost his company’s profitability.  Late in 1955, Carlo made contact with Elio Zagato specifically to discuss an idea he’d been mulling over – that Abarth should combine a Fiat chassis featuring the derivazione Abarth 750 enhancements with a small, lightweight coupe body made by Zagato in a series production offering.  The Milan-based carrozzeria had already constructed such a car in the Spring of 1955 and was not only interested in Abarth’s proposition, it was swift in response, with early examples of the formula appearing in the Spring of 1956 at Monza and at the Mille Miglia.  That year saw a process of refinement of the way in which the aluminium bodies were constructed and then mounted on the chassis as completed vehicles.  Within this process the roofline was reconfigured with the headroom requirements of taller drivers in mind, to feature the double humps which soon led to the model’s nickname, ‘Double Bubble.’  The earliest 750 Zagatos – made before March/April 1956 – have chassis numbers below 150XXX.  Double Bubbles, in production from late Spring onwards, tend to carry chassis numbers in the range 200XXX.

The model first appears in Abarth internal records as Project #17, June ’55, FIAT ABARTH 633-750 Coupe Zagato 1st Series.  Data includes: Tipo 219-A/S engine, giving 47 bhp @ 6000 rpm; 4 speed Fiat 600 gearbox; weight – 605 kg.  The specifications remained in place until the following February (1956), with minor revisions, (a very small increase (3 kg) in weight, for example), attributed to Project #21, and designation as 2nd Series.  A little confusingly, this was soon followed up, in April, by Project #24, which referred again to ‘1^st Series,’ for which an increased compression ratio is noted, together with a Weber 32 IMPE carburettor in place of the previously employed 32 DRNP.

It is logical that a substantial proportion of orders were for a car with race-ready specification.  Referring to #248883, Bonhams in recent times included the following in its auction sale lot description: ‘(The car) was manufactured to Corsa specification with Plexiglas side and rear windows.’  However, the 750 Zagato authority, John de Boer, has said, ‘It has become popular in recent times to describe a certain batch of cars that exhibit certain characteristics specifically as "Corsa" versions.  I am unaware of a "corsa" designation being any kind of official moniker for these cars.  Some cars were built in batches sharing certain characteristics that seem more likely to imply racing intent or actual use.’  

John de Boer’s long term, in-depth work on data defining individual cars and the production history of the 750GT model family is an essential reference source, with unique insight into certain aspects which are largely undocumented elsewhere, especially the early chassis completed without the involvement of Abarth, the batch of cars built for Abarth by the Turin carrozzeria, MECAT, and the U.S.-specific Sestrière model.  But, notwithstanding his assertion above, a 2008 H&H auction description for #383101 includes this:  (The ‘Corsa’) often benefited from plexiglass side/rear windows, reinforced C-posts, alloy rear window frames and smaller front indicators, not to mention a close-ratio gearbox, enlarged fuel tank, tuned engine (thin walled sump, pancake air filter etc) and higher marked rev counter.  Smaller, lighter and faster than its purely road-going sibling, the ‘Corsa’ could also be had with an optional auxiliary radiator (mounted underneath the car).  However, as each one was prepared for a specific client some boasted more of the aforementioned features than others.  . . . (This car) it was confirmed to me by Guy Moerenhout Racing of Belgium – an acknowledged specialist in all things Abarth – as having one of the twenty-one ‘Corsa’ type bodies.’

Guy has been kind enough to further elaborate on the subject of the Corsa.  Especially helpful was the provision of a list of features:  47 bhp Mille Miglia engine with highly polished rods/crank (lightweight) and alloy 5 quart finned sump; Alloy drum air cleaner; Aluminium rimmed Plexiglass door and quarter windows; Plexiglass rear window; 10 gallon fuel tank; Bendix electric front mounted fuel pump; Record Monza-type bucket seats; Nardi wood-rimmed steering wheel; European 5.25” Marchal headlights; Italian licence plate frames, front and rear; Large, finned alloy front brake drums; Early Fiat 600 tail-light or Lucas lenses; Alfa 750-type, small front indicator lenses; Mille Miglia badge on dashboard; No flank badges except The Zagato ‘Z’ to the rear of the front wing; No front air ducts under the nose; Underbelly auxiliary radiator; Single 1956/57  Champion of Italy badge on rear deck; Small round badge above the front grille, (no Fiat script); Small Fiat Derivation 750 badge on decklid (6” long).

In the 2008 Bonham’s sale mentioned above, #248883, is described as a 1956 Fiat-Abarth 750 Zagato Corsa.  This car was I think actually manufactured in early-mid ’57.  Photographs attached to the auction lot details show compliance with several of the features noted in the paragraph above, notably: No flank badges except the Zagato ‘Z’ to the rear of the front wing; No front air ducts under the nose; Small Fiat Derivation 750 badge on decklid.

Double Bubble Corsa (?) - #248883 (early-mid-‘57):

This is a simplified timeline outlining the production history from 1955 through to conclusion.  Reference sources are:  (Greggio) The Man, the Machines by Luciano Greggio;  (Secc) Abarth, The Scorpion’s Tale 1949-1972 by Sergio Seccatore;  (DegRiz) Abarth. All The Cars by Elvio Degamello and Arturo Rizzoli;  (GastSecc) Abarth. Memories by Luca Gastaldi and Sergio Seccatore;  (Cos) Abarth Guide by Alfred Cosentino;  (BoSt) Abarth Racing Cars Collection, 1949-1974 by Stefan Bogner and Franz Steinbacher.

 
’55       Derivazione 750 - Fiat 600 conversion kit. Bore 60>61 mm, stroke 56>64 mm – 633 cc>747 cc.  Inlet manifold, Weber 32 IMPE (Fiat = 22 IM), compression ratio 7.8>9:1, Abarth exhaust, 21.5 bhp>41.5 bhp. (Greggio).
 
04-’55   Turin Motor Show – Abarth proposes a deal to Elio Zagato to create a 750 GT. (Greggio).
 
06-’55   Tipo 219-A/S Series 1 750 Coupe Zagato 47 bhp, 605 kg.  In Vol 1 Summary of Projects table – 217-A.  (Secc).
 
02-’56   Tipo 219-A/S Series 2 750 Coupe Zagato 608 kg.  In Vol 1 Summary of Projects table – 217A. (Secc)
 
03-’56   Zagato coupe with 750 mechanicals ran at Monza. (Greggio).
 
03-’56   Geneva Motor Show – launch of Abarth 750GT Zagato . (the following month, at the Turin Show, Abarth showed two Bertone 750GTs, but neither were greatly liked and very few were built).  (Though empathy between Carlo and Nuccio led to the Bertone-bodied 750 Record).  (Greggio).
 
03-’56   First wins – 19-03-’56, Enrico Carini, Monza, Trofeo Vigorelli, 2^nd overall, 1^st GT 750.  (Racingsportscars.com)  25-03, E. Carini, Trofeo Torricella hillclimb (Greggio) and, same date, ?Harris, Course de cote de la Roche hillclimb (Greggio).
 
04-’56   10 cars entered in Mille Miglia, ‘Abarth derived Fiat saloons, one of which won the 750 cc GT prod class, driven by Domenico Ogna.’ (Greggio).
 
04-’56   Tipo 219-S Series 1 750 Coupe Zagato 47 bhp, 535 kg (Secc)
 
09-’56   02-09-’56 Enrico Carini, Monza, Coppa Inter Europa (GT 750 class)
 
10-’56   21-10-’56 Mario Poltronieri, Castelfusano, GP Roma (GT 750/T 750 class)
 
’56 season – according to Greggio, had 5 victories in GT 750
 
05-’57   Tipo 219-C Series 2 750 Coupe Zagato 43 bhp, 535 kg (Secc) Changed features: Rear optical group, bumpers (Greggio)  (rally?) (?’58 Sestriere Rally winner?)  Rear optical group, bumpers
 
07-’57   Tipo 219-C Series 1 750 Spider Zagato 43 bhp, 505 kg (Secc)
 
07-57    105/CZ Fiat 500 modificato Abarth 479 cc, 20 bhp, 465 kg (Secc)
 
10-’57   500 GT first showing at Turin Motor Show
 
10-57    ‘Definitive double hump’ roof on 750GT shown at Turin Motor Show' (Greggio)
 
10-’57   Bialbero engine, 61 bhp, in Record 750GT (Greggio)  Greggio says the first version (no date given) 57 bhp
 
02-’58   ES 01, Tipo 222 700 Coupe Record Monza Zagato 66 bhp, 565 kg (Secc)
 
02-’58   ES 01, Tipo221 750 Coupe Record Monza Zagato 57 bhp, 568 kg (Secc)  Greggio says smooth roof, 3 pane rear window, horizontal wraparound bumpers, ‘ample’ central intake vent in bonnet, rounded rear end, no little tails on the far end of the wings. 540 kg.  Production run of 100 for GT homologation.
 
(https://www.no-speedlimit.it/index.html): “By the time of the appearance of the Abarth Zagato Record Monza 750 Bialbero, the bodywork had been unified into a separate model with a rather large hump on the engine lid, made necessary by the taller twin-cam motor. There were then three distinct models: 750 "Double Bubble," 750 "Record Monza", and 750 "Sestrière."
 
03-58    (Following high success of Abarth 500 Nuova) Agreement by Fiat to the payment per race victory to Abarth and production of alleggerita 600 for supply to Abarth begins.
 
Late-’58 Corso Marche opens
 
03-’59   USA debut - 4 x Record Monza 750s run at Sebring
 
04-’59   Tipo 215 750 Coupe Sestrière Zagato 52 bhp, 555 kg (Secc).  Several sources say run of 25 cars built ‘mostly’ for the USA.  https://hypercars.io/listing?id=412871 says: “It is not known how many were produced, some say 25+, my information suggests the number is higher, possibly more than 32.  Fiat Abarth 750GT Zagato Forum  says steel body/no roof bubbles and either 215 engine (748 cc) or 213A (785 cc).”  Bonhams: A special model named the "Sestrière", as seen here, had upright fixed headlights and was built normally in steel with aluminium doors*other sources, with two prominent air scoops atop the tail for better engine cooling.  No Speed Limit: the majority were built with a steel body, a very small number of alloy cars, and there is one aluminium car known to exist today.
 
06-’59   ES 02, Tipo 220 850 Record Monza Zagato 70 bhp, 570 kg (Secc)
 
01-’60   ES 02 Tipo 214-B 850 Coupe Stradale Zagato 52 bhp, 590 kg (Secc)

I suspect that this will forever be an ongoing work-in-progress.  By virtue of the type of vehicle this is, and the sort of enthusiasts that typically own examples, cars seen/photographed today may well display features which have been added/modified over the years, long after they left the factory – such customisation is especially commonly seen in regard to badging, trims and wheels.  And, as regards the details of any 750GT as it left Corso Marche, such is the accuracy/completeness/availability of the contemporaneously-recorded data concerning production of the cars, that there will be many aspects of their specifications which will remain uncertain/disputed.  I do not pretend to have access to any magic bullet processes or data sources which would resolve such issues.  All I have done here is to collect together and systematically organise existing information with what I hope is an appropriate level of discretion.  But, even so, I’m sure there will be readers with far greater first hand knowledge of the cars than I have who will perceive misunderstandings/anomalies in what I’ve written.  That being the case, I’m very keen to receive appropriate feedback so that the document can be refined and improved – so please don’t hold back!

Part 2 will cover details of the cars' bodywork, badging and trim.