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.