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.

Eight on the way to Twelve – the Abarth V8 Engine

Much was positive for Abarth as 1965 dawned.  Especially so in terms of the marque’s racing exploits.  For three years in succession, Abarth had taken GT World Championship honours, in the 1 litre class in ’62, 1.3 in ’63 and ’64.  In addition to these top-flight achievements, Abarth victories in national, regional and club events were commonplace, providing the Corso Marche treasury with regular and substantial income stemming from the ‘57 agreement whereby Fiat made a payment to Abarth for each and every race win credited to one of its Fiat-based models.

 

But there was a downside to this apparently generous, sugar daddy arrangement – to maintain the competitiveness of Abarth’s numerous racing customers, across a wide spread of model types/variants, it was necessary to implement an ongoing programme of product development and resulting upgrades.  This was an expensive business – enough so to be prompting Carlo Abarth, Renzo Avidano and Carlo Scagliarini to consider a major strategical revision of Abarth & C’s operational style and commercial objectives.  Whilst this would need to include an upscaling of road car production there should be no implication that racing would become a just an incidental, low key aspect of Abarth’s activities.  Indeed, Carlo sought to optimise the commercial benefits accruing as a result of his company’s motor sport expertise.  But, whilst up to that point Abarth was associated mostly with the smaller engine capacity classes, for a higher profile and thus a more powerful halo effect to enhance the marketability of the road cars, there needed to be a new focus on ‘bigger’ racing models which could contend for victories in the most prestigious categories, such as the impending FIA Groups 4, 6 and 7 for prototypes/limited production sports cars.  This was the media coverage-attracting realm of the World Sportscar Championship and events at places like Le Mans, Nurburgring and Monza.  In addition, there was soon to be the Can-Am Challenge, providing a potentially lucrative channel to the U.S. automotive market.  Equally, there was much to be said for the commercial opportunities that could flow from participation with a Grand Prix car in the Formula One World Championship.

 

Any such undertaking would, however, require substantial immediate investment, particularly in terms of engineering innovation and effort.  Abarth would have to step beyond its comfort zone – the world of relatively simple, two and four cylinder in-line engines.  What had been achieved in working with such powerplants was not to be dismissed – after all, the 2 litre 4 cylinder Tipo 236 unit would be giving all of 270 bhp in ’71 as Abarth was absorbed into Fiat.  However, in aiming to run against a competitor such as Ferrari fielding cars with 3 litre engines, Corso Marche was going to have to be the birthplace of an 8 cylinder motor.  That established, it wasn’t difficult to conclude that this would be best configured as a 90° V8.  And, once you’d got comfortable with that as a notion, with somewhere like Le Mans in mind it was not so hard also to start contemplating the possibility of a 120° 12 cylinder of twice the capacity!

 

Understandably, there has been speculation as to why Abarth chose in ‘66 to launch its first V form engine with a capacity of no more than 2 litres.  According to Gianfranco Bossu - colleague of Luciano Fochi, Abarth’s engine designer - the original proposal was to create the engine as a means to compete with Ferrari in the European Hillclimb Championship.  This implies a lack of confidence in how much more power could be extracted from the 1946 cc 4 cylinder, 16 valve tipo 236B, then good for around 245 bhp.  But what about the competition? – as an example, the 2 litre Alfa Tipo 33 at that pointed boasted 260 bhp.  So Abarth should really be seeking to run with at least something in the 270/275 bhp range.  From the ’65-’67 perspective, 30 more bhp from the 4 cylinder was a very tall order.  To achieve such an increase, an 8 cylinder was essential, both to allow for future displacement growth and to ensure that individual components could be operated under less stress, thereby enhancing reliability/durability, characteristics so important in the longer distance World Sportscar Championship events.  For ’67, both Prototypes (limited to 3 litres) and Sportscars (limited to 5 litres) also featured an up-to 2 litre class.  The 2 litre capacity gave Abarth options in terms of event classes/categories.  Until competitiveness had been established, ‘class wins’ would be possible even if overall victory would not.

 

The all-alloy, four cam Tipo 239 engine was first presented publicly at the Turin Racing Car Show on 26^th February ’67.  With bore/stroke dimensions of 78 cm x 52 cm, the cubic capacity was 1987 cc.  The launch specification included twin spark ignition and four twin choke Webers.  With an 11:1 compression ratio, this initial set-up was said to be good for 230 bhp at 9,000 rpm.

Fig.01 Tipo 239 engine. Courtesy Berni Motore

With thanks again to Gianfranco Bossu, we know that the initial bench testing yielded very disappointing results in terms of both power and torque.  Gianfranco recalls that there was an immediate decision not to embark on an improvement programme and the project was in effect abandoned, the engine never chassis-mounted for track testing.  At the time, the Tipo 236’s maximum output was reported as being 220-230 bhp.  It is reasonable to infer that with the given greater weight of the Tipo 239 engine and its power being no more than 230 bhp, a V8-engined version of the SE04/L* would have been no quicker than one powered by the 4 cylinder.  Logically then, a decision to enlarge the Tipo 239 to 3 litres while tackling 2 litre class racing with the Tipo 236 seems well justified.

*The SE04 chassis which had been developed from the previous year’s 1000 SP model.  Thus it had a tubular chassis with mid-located engine, a car configured according to Mario Colucci’s thinking rather than Carlo Abarth’s.  However, a superficially similar car with box section chassis members and outboard engine had been built for comparison purposes.  First seen in May ’66 was a 982 cc engine-powered barchetta, of which 50 were built during the next 18 months, enabling it to be homologated for Group 6.  The two versions were tested at Vallelunga in January ’67, at this stage powered by the 4 cylinder Tipo 236 engine.  Evaluation concluded that future development should be with the mid-engine/tubular chassis configuration, designated SE004/FB2.  Rapidly forthcoming from the programme was a longer wheelbase version, identified as SE004/L.

 

Fochi pitched to Carlo Abarth the notion of increasing the cubic capacity, redesigning the heads with 32 valves and offering the engine on commercial terms to private customers.  Abarth apparently dismissed this idea out of hand, but authorised an evolution project for ’67 whereby the capacity would be taken up to 2968 cc.  This was achieved by increasing the bore to 88 mm and the stroke to 61 mm.  The prototype engine was put on the bench on 23 September ‘67, delivering 312.3 bhp at 8000 rpm.  It was first installed in a SE004/L chassis but soon mounted into a development of that car, designated SE013.  In what was otherwise known simply as a 3000 Sport Spider, the 3 litre Tipo 245 V8 made its race debut, a few days after its press presentation, on 6^th October ’68 at the Aspern Airport circuit in Austria.  Especially noteworthy was the high location of the coolant radiator – above the top of the roll-over bar – over the rear of the mid-mounted engine, a concept anticipating Gordon Murray’s experimental external cooling solutions with the Brabham BT46 the following decade.  The SE013 at this point had ‘nervous’ handling tendencies which were exacerbated by the heightened centre of gravity to which the radiator significantly contributed.  Despite this, works driver Peter Schetty put the car on pole and comfortably won the race from Arturo Merzario, who was running in Group 6 with a 2 litre Sport Spider.  At Innsbruck, Schetty recorded a second 3000 circuit victory on 20^th October.

Fig.02 Tipo 245 engine. Courtesy Berni Motore

Despite the ‘first time out’ victory, there was ready recognition that the car would not be competitive at higher profile events because of its handling characteristics.  With an ambition to run at the 24 Hours of Le Mans in ’69, it was essential that it be made easier/less taxing and tiring to drive.  But early-year progress was limited, leading to a decision that although an entry had been made, a Tipo 245-powered car would not be sent to Le Mans.  Instead, effort was invested in the evolution of the SE013 into the SE016, first shown on 2^nd September ‘69.  Obvious at first sight was relocation of the radiator to within the body and the addition of tabs on the front/lower ‘corner’ of the front wings, both measures deemed important in seeking better overall balance and to militate against the car’s propensity to generate front end lift.  Another change expected to deliver better handling was to 15” wheels, (from 13”).  However, at this point, and for an extended period, such components were impossible to obtain from the usual suppliers because of widespread workers’ union-led strikes.  Driven by Johannes Ortner, the car was nevertheless competitive, (3^rd when the race was prematurely stopped), at the 500 km of Imola, run later in the month.

Fig.03 SE013 left, SE016 right. Courtesy Berni Motore

In ’70, there were notable hillclimb victories for 3000 Sport Prototypes at Barisart (Belgium), Avignon (France) and Bergamo (Italy).  In late October, Abarth presented an upgraded version of the ‘3000 Sport Prototype,’ (SE020), at the Turin Motor Show.  Most notable revisions included a shorter wheelbase, more forward-located cockpit, extreme rear-mounted oil coolers and twin side placed coolant radiators.  The engine was upgraded – taking power up to 365 bhp – with the installation of fuel injection (Lucas) and capacitive discharge ignition (Dinoplex).  Despite these improvements, there was not a lot of confidence at Corso Marche.  Morale had been affected by a reduction in Abarth’s profitability and the disruptions attributable to Italy’s industrial relations strife experienced over the preceding three years.  Overlaying these fundamental concerns, was an internal recognition that the SE020 would struggle for competitiveness against the main Group 6, 3 litre class rival machines.  Though the Abarth V8’s power output was not greatly lacking in comparison with that of Porsche’s flat 8, (908/2), it was over 30 bhp down on the Alfa T33/3’s V8, and almost 100 bhp less than what the Ferrari flat 12 (312 PB) could muster.  A solution would be to resurrect Fochi’s 32 valve heads proposal, but with corporate financial robustness being as reduced as it was, that was a project which would again be deferred.

Fig.04 Carlo Abarth and Arturo Merzario stand behind the SE020, February '71

However, there was a niche which could be successfully exploited.  With a consistent record of good results in the category, there was a belief at Corso Marche that a bespoke version of the 3000 Sport could be a Group 5 contender for the European Hillclimb Championship.  Thus, the SE022 was unveiled in February ’71 at Campo Volo.  Designated a Monotipo, the SE022 was functionally similar to the SE020, but featured a substantial, enveloping-style windscreen frame/glass and carried a spare wheel for regulations-compliance.  ’71 saw nineteen 3000 Sport Prototype high profile hillclimb victories at Bellvue (Belgium), Draguignan (France), Liege (Belgium), Presberg (Germany), Villach (Austria), Gap (France), Jura (France), Abreschviller (France), Autun (France), Consenza (Italy), Berchtesgaden (Germany), Brescia (Italy), Avignon (France), Berwinne (Belgium), Clouneaux (France), Vuillifans (France), Trento (Italy), Sestriere (Italy) (2 classes).

Fig.05 SE022 driven by Johannes Ortner at Sestriere, July '71

Despite a visually appealing presentation of the three new Sport Prototypes and Carlo’s confident bearing at Campo Volo that February day in ’71, as an event this was a swansong.  On top of all the problems associated with the commerciality of the road car business and shortage of capital, a lack of confidence had been growing in Abarth’s motor sport customer community.  To ensure that such customers should not feel they were getting second best to the works team, Abarth created a division which could be seen as separate, self-sufficient and having 100% customer-focus.  He appointed Enzo Osella as its head, confident of the man’s expertise, abilities and alignment with his own principles.  At the same time he conducted a difficult negotiation for the sale of his company to Fiat, the confirmation of this being made in mid-October.  Fiat in effect endorsed the semi-external racing arm by delegating responsibility for the Abarth marque’s participation in the European Championship (for prototypes) to Osella for the ’72 season.  However, this did not involve utilisation of the V8 engine, and the cars became known as Abarth-Osellas.  But if that sounds like a downbeat development from a Corso Marche viewpoint, the upside was that with the Tipo 236 engine generating 270 bhp on Lucas fuel injection and a more reliable Hewland gearbox replacing the Abarth Tipo 139 unit, the Abarth-Osella SE021 was the championship-winning car of ’72.

The Fiat 850-based Abarth OT Coupes

Whilst the Fiat 600 had provided a good chassis/mechanical basis for the scorpion-badged Grand Tourers of the early Sixties, it had been necessary for Abarth to create bodies of a style appropriate for the GT designation.  These cars reached their performance and aesthetic high point around 1963/4 with the 1000 Bialbero, alongside the Simca-based 2000 GT.  Just at that time (March 1964) Fiat introduced the 850, a model family that not only offered new performance possibilities with the enlarged engine capacity, but also a ready-made suitably styled coupe body.  Abarth was quick to get to work on the 850 with a 60 bhp Berlina OT (Omologata Turismo) 982 cc version in October.  The Coupe was introduced by Fiat in 1965 and that September Abarth launched its OT 1000 version.  The enlarged Tipo 202 engine was good for 60-65 bhp.

Abarth’s considerable achievement in taking class ‘World Championships’ in the period 1962-67 was in the main due to the performance of the 1000 GTs, Simca platform GTs, 1000 Berlinas and 1300 OTs.  The OT 1000 Coupe was not favoured for international race participation but was successful from the outset as a customer racer for national events.  The OTR version appeared along with the OT in autumn 1965.  The car in standard form (74 bhp) was suitable as an ‘off the shelf’ race car or, uprated with factory options, in enhanced competitiveness trim, (95-105 bhp).  The engine was based on the Tipo 200 but with a new ‘radiale’ head and improved cooling thanks to a nose-mounted radiator.  The form of the combustion chambers in the radiale engine is apparent in the photograph below – two overlapping hemispherical voids which, together with individual, separate, exhaust ports and twin Weber 40 DCOE carburettors, made for highly efficient atomisation, induction and gas flow characteristics.  As a result, the engine was considered to be ground-breaking in developing 100 bhp from a sub-1000 cc capacity.  The performance was all the more remarkable since the engine was capable of running at over 7000 rpm despite having pushrod actuated valve gear.

The adoption of the forward position radiator dictated the need for redesign of the car’s front panel to provide an air intake aperture.  The resulting grille, script and central badge lent the nose a distinctive and aesthetically pleasing character.

However, exploitation of the new engine was soon compromised.  In the U.S., the motorsport-governing Sports Car Club of America, took against the OTR and ‘banned’ it, believing the extent of modification to be extreme and outside the spirit of the rules of their relevant racing classes.  This significantly constrained sales potential in such an important market for Abarth.  Accordingly, it is generally held that less than forty OTRs were built by Abarth.  The Sixties were notable for the instability of racing class definitions and related homologation rules.  Abarth was frustrated in being unable to gain Group 2 homologation for the radiale cylinder head, only able to achieve this in 1970.  For Abarth it was important to have models which were ‘legal’ for as many classes as possible.  This gave rise to a further 1000 Coupe variant – the OTS, utilising the OTR body but powered by the standard cylinder head engine (67 bhp).  This was successfully homologated in 1966 for FIA-governed GT racing.  Alongside, a higher powered (90 bhp, achieved with carburation/manifolding upgrades) OTSS version was also offered.

1966 was a hectic year at Corso Marche, as indicated by this list of newly emerging variants on the Fiat 600 platform: OT 1600 Prototipo; 1000 TC Berlina Corsa; OT 2000 Coupe America; OT 2000 Coupe; 1000 TC Radiale Berlina; OT 1300 Sport; OT 1600 Coupe Prototipo.  And there was one more, which is especially relevant to this post – OT 1300/124 Coupe.  Unveiled at the Turin show in November, this was somewhat unusual in comparison with the 1000 versions since the engine was only mildly modified by Abarth.  However, the larger capacity of the 124 engine, oversquare bores and raised compression ratio enabled a relative unstressed output of 75 bhp.  Both front and rear suspensions were also upgraded whilst the ride height was lowered and the track increased.

Abarth won the last of its 6 consecutive FIA championships in 1967 with the OT 1300 – however, to avoid possible confusion, it should be understood that this car was Simca-based and featured a Sibona & Basano-made fibreglass body, unrelated to the Fiat 850 coupe shell.

In 1968 Fiat facelifted the 850 Coupe, adding ‘Sport’ to the model designation.  From a mechanical viewpoint, the main upgrade involved the engine, capacity being taken out to 903 cc.  Cosmetically, the most notable changes affected the front end, incorporating 4 lamps, repositioned indicator lamps and reshaped/front panel featuring a ‘v’ shaped chrome embellisher.

An Abarth OT 1000 version of the 2^nd Series Coupe was launched in 1969 and for some time this was in production alongside a similarly updated OT 1300/124 Coupe, ending in 1970.