Further to last week’s dissertation on the 1979 Alfa Six, we examine the contemporary reception to Giuseppe Busso’s Alfa Romeo 2.5 litre V6 unit, through the acerbic eye of LJK Setright.
Some engines arrive fully formed, others however, enter the world imperfect, but through a process of development and retrospective correction evolve to defy their early criticism.
A fundamental element of Alfa Romeo’s iconography was intrinsically linked to its engines, especially its pre-war thoroughbreds, those patrician in-line fours, sixes and eights which powered the carmaker into history books, not to mention the hearts and minds of all those with the blood of Portello coursing through their veins.
It was therefore an event of no little note on those rare occasions when Alfa Romeo introduced a new power unit, especially given that apart from the horizontally-opposed Alfa Sud unit, the storied Milanese carmaker had relied upon various derivations of twin-cam fours since the 1950s.
Of course what that statement conveniently ignores is the in-line six that powered various 2600 saloons, coupe’s (and a few convertibles) from 1962 to 1967, an engine which perhaps fell somewhat short of the high ideals, to say nothing of the expectations of the faithful.
The 1979 introduction of the Alfa Six was notable therefore, not simply because it represented the Biscione’s first attempt at an ‘ammiragila’ since the 2600’s demise, but more so because it also marked the debut of an entirely new, first-principles multi-cylinder power unit.
A six cylinder Alfa Romeo power unit seemed on paper at least to be a highly alluring prospect, so it was with some bemusement that the engine itself, designed under the supervision of Ing. Giuseppe Busso, was not only of a configuration not immediately associated with the marque, but contained within it, a number of technical solutions which, rather like the Jaguar V12 of 1971 departed noticeably from hitherto sacrosanct technical orthodoxies.
Alfa Romeo went to some lengths in 1979 to justify the adoption of a V6 layout for their new six, citing its connection to eminent engineer, Vittorio Jano, who was responsible for a number of legendary Alfa Romeo engines as technical director at Portello during the 1930s – although as LJK Setright somewhat waspishly pointed out in his June 1979 technical review for Car magazine, the engines Jano was associated with at Alfa Romeo were in-line units of six or eight cylinders.
Of course, following his dismissal from Portello in 1937, Jano went on to do what was arguably his definitive work at Lancia, and it was here that alongside Francesco di Virgilio, the first production V6 engine was developed for the Aurelia. Jano later went on to inspire the superb four-cam Ettore Zaccone Mina-designed V8 GP unit and latterly, the compact 65° Ferrari V6 which would (also) power Scuderia Ferrari to innumerable Grands Prix victories.
But if the connection between Alfa Romeo and the V6 configuration was, to say the least, tenuous, the engine itself was meritorious – albeit, this did not mean that some of its technical conclusions were viewed as being anything other than regressive, eliciting a theatrically raised eyebrow from Car’s resident engineering purist.
Arguably at least by the late 1970s, and certainly by the predetermined technical standards of Arese, the use of pushrod operated valvegear was not cutting edge technology, to say nothing of the employment of six individual carburettors, when fuel injection was already not only widely prevalent but preferable.
In his 1979 essay, Setright appeared at pains to debunk Alfa’s justification for their new engine, pointing out Alfa’s (correct) claims that their 60° unit was smoother running than rival units like the Douvrin 90° unit fitted to a variety of European rivals, but noting that while the Busso unit was narrower than a 90° configuration, it was also taller – albeit less so than an equivalent in-line engine.
However, (to paraphrase the late Jim Randle), despite the crankshaft not being the sort of thing one would ideally choose to have as a desk ornament, it was nevertheless a good deal shorter and torsionally stiff than that of a straight-six.
And if torsional stiffness might have aided the cause of smooth running, Car’s monocoled mutineer looked askance at the V6’s valvegear. Ingenere Busso either specificed or had imposed upon him the requirement to avoid unnecessary complication (perhaps bulk and certainly cost) and so the Alfa V6 employed single overhead camshafts operating at an included angle of 46 degrees 45 mins into part-spherical combustion chambers.
The larger inlet valves (41 mm in diameter) were directly actuated from the camshaft by piston-type tappets, while the smaller exhaust valves were actuated using short transverse pushrods and rockers – akin, LJKS suggested to pre-war BMW/ Bristol methodology.
Setright lamented the engine’s good but not brilliant inlet valve area in relation to the pistons (21.7%), and appeared to infer that the Alfa’s complicated valvegear would lead to an unnecessarily noisy engine – a matter for which he may not have been in error – albeit, the quality of the noise is often of more significance than the disturbance itself, and one thing which can be said of the Busso V6 is that in any configuration, the noise it left in its wake was a pleasing one.
Ing. Busso’s engineers went to the trouble of providing a sound spectrum analysis, showing the noise reaching the driver’s ears at 120 km/h – a road speed which the carmaker stated would only require 80 bhp and 3725 revolutions per minute to propel the car – and which appeared to back up Setright’s assertion insofar as the “loudest apparent noises are at 12, 18, 24, and 36 vibrations per [crankshaft] revolution, which are clearly harmonics of the basic mechanical and combustion pulsations.”
In addition to the complex valvegear, LJKS also pondered whether the source of engine harshness might have been related to the “instant and uniform” combustion Alfa Romeo made much of in their launch material, Arese claiming that at 415.3 cc each, the V6’s cylinders were ideally sized for thermal and volumetric efficiency – a matter which dear Leonard refuted as nonsense, citing SAE papers by Honda as proof. Indeed he asserted that were the engine to display the former trait for which Arese’s PR representatives claimed, the V6 would in fact blow itself to pieces.
But if Setright was perhaps a little uncharitable about aspects of the design (and the manner in which it was presented to the press), he was nothing if not prescient in his perceptions – no more more so than when he observed; “What is easier to accept is the idea that the V6 may one day sprout four valve heads, in which case this valve-operating mechanism may begin to make sense.”
Possessing a lower stroke to bore ratio than its putative rivals, it was clear from the start that Arese had bigger plans for the unit – clearly then, cylinders of 500 cc each were better still…
Setright concluded in a more consiliatory tone, noting; “A pinch of salt should suffice. Much better to attend to the opinions expressed by those who have driven the car and are competent to judge it: they seem to like it, and that makes it likely that the 2500 is a good car.”
What we now know is that whatever the merits of the Alfa Sei as a vehicle or indeed an Alfa Romeo, Ingenere Busso’s V6, much like Mr. Hassan and Mundy’s Coventry-bred V12, evolved into very fine engine indeed – arguably perhaps, one of the greatest.