Do French engines live up to that nation’s fine engineering heritage?
In Post War Europe, engines were restricted by reasonably arbitrary taxation classes. In Britain, the old ‘RAC Horsepower’ rating was based on an archaic formula that related to the bore only, not the stroke and didn’t actually refer to the actual output of the engine. Despite it being abolished in the late 1940s, it meant that the longer stroke engine, with its relatively low rev limit, lived on far longer in much loved stalwarts such as the Jaguar XK and BMC A Series and it did stem the development of lighter, freer running engines. Italy was less prescriptive and, although there were aberrations, like home market only 2 litre Ferraris and Alfas V6s, it allowed the development of the sweet engines found in the Alfas and Fiats of the 60s. The French tried to be more scientific, with a fiscal horsepower tax that brought in various factors but, generally, encouraged smaller engines of 4 cylinders and less. Thus, in a country that has a fine record in technical advances in motoring, engines struggled to keep up.
Citroën, when they actually were producing truly ‘Créative Technologie’ twenty-five and more years ago, did not generally match their adventurous cars with the engines. The 2CV flat twin was a fine engine – clever, rugged, characterful and able to be repaired by those of modest skill, such as me. The spiritual big brother, the air-cooled flat four of the GS of 20 years later, was also fine in its way but, in hindsight, that incredibly advanced small saloon should have had something quieter – in other words a water-cooled flat four or the Wankel engine that was planned. Big Citroëns however were not well served. There is a direct descendancy from the wet liner four used in the 1934 Traction to the engine of the last CX GTi Turbo. This was a fair, but not outstanding engine at the start. By the time it died it was producing an impressive amount of power, bearing in mind its rudimentary design, but not with any degree of smoothness or economy.
Citroën’s historical excuse for the unseemly longevity of its wet liner four is that the carry-over of the 3 bearing unit from the Traction to the original DS was unintended, being an eleventh hour decision when it was realised that the proposed air-cooled flat 6 was not going to materialise. In fact the flat 6 would have been mounted ahead of the engine and, as such, the front part of the car would have been engineered very differently. Therefore the dumping of the intended engine was more like a ninth hour decision, which could have given them more time to better update their 20 year old engine. However, as was always the case with Citroën, it’s likely that funds were low and a pragmatic choice was made.
Another 20 years later, and the carry-over of the now 5 bearing unit from the DS was intended as a temporary measure until the proposed rotary engines for the CX came on line. Unfortunately the Comotor project turned into tragedy as reliability and fuel consumption became insurmountable issues. The futuristic CX was therefore, in larger capacity form, condemned for the whole of its lifespan to a rough push-rod engine whose roots, by the end, went back over half a century. The only other Citroën powerplant of note was Alfieri’s V6 Maserati engine for the SM, which was an excellent and unfairly underrated engine, compact, flexible, fine sounding and produced in record time (not, incidentally, by sawing two cylinders off a V8 as the myth goes) but it would have benefited from a capacity of maybe 3.2 litres, not the 2.7 litres that French tax decreed and, anyway, it was not a French engine.
From the mid Seventies onwards, Citroën were of course using whatever engines its new masters, Peugeot, saw fit to let them have. The best you’ve usually been able to say about mainstream Peugeot and Renault engines is that they do their job, though that should be seen as faint praise as long as they do it without fail – much as I love the Citroën twin, the four cylinder of the Renault 4 arguably did all that engine could do, but at a more civilised noise level. In the Sixties, Peugeot were early to produce a fuel injected petrol engine for the 404, which impressed testers. However, the growing unimportance of engines to PSA and Renault came to its peak in the next decade with the Douvrin four. Previously proudly independent, here were two manufacturers deciding that what went on under the skin maybe didn’t interest punters that much, so why not split the development costs? In fact this had a then recent precedent in the Comotor project between Citroën and NSU but, whereas that was a brave undertaking that unfortunately failed and brought down two fine companies, this was to be an exercise in penny-pinching and playing safe. Passable beyond belief, the Douvrin engine behaved just like you’d expect of the committee specified device it was. It had a V6 brother, the PRV, whose only similarity to the free revving Maserati V6 was its 90 degree cylinder configuration. It could be tweaked and tuned to be quite sporty and exciting but, in its natural form, like its small brother it was outstandingly ordinary. Nevertheless, it might have been nice for Peugeot to let Citroën fit it into the CX for a bit of the six-cylinder smoothness it craved but this never happened, supposedly for fear of affecting Peugeot 604 sales.
Sometimes, if not quite at present, Renault might be at the top of Formula 1 and their hot hatches might be breaking Nurburgring records, but that just makes the stultifying behaviour of their everyday engines all the more grating, and only excusable when they work. Nigel Mansell’s World Championship was made particularly irritating for me at the time by a persistent and hard to diagnose misfire in a well maintained 6 year old carburetor fed Douvrin-engined Renault Espace. That was one breed that racing hadn’t improved. All the recent Renaults that I’ve driven seem to be biased more for the convenience of marketing folk able to tout unachievable fuel consumption figures, than for my comfort or pleasure.
Anyone reading the above might notice the lack of reference to diesel and, of course, the French were early adopters in the DERV revolution, with Citroën taking the dubious accolade for the first diesel car in 1933. Then followed a lull, since diesel was not offered in the Traction or DS, and it wasn’t until 1959 that Peugeot really got the French industry going with diesel and, relatively speaking at least, offered better performance over the next few years than their only real competitors in oil-burning, Mercedes. From then on there was no looking back and, for the next 30 years, Peugeot, then PSA, were at the forefront of developing car diesel engines that were, at least, half civilised, and employing them in their cars and those of other manufacturers. I do however agree with our Editor that a diesel will never be more that half civilised. The other half is busy belching out carcinogens whilst teams of engineers toil to diminishing returns to filter them to acceptable levels. The low fuel consumption of early diesels might actually have been matched by petrol engines, should you have driven them at the pitiful performance levels that diesel then allowed, a task that would have been made easier by the horrendous understeer risked from having an extra 80kg under the bonnet. However, in France, the situation was skewed because diesel was considerably cheaper than petrol and, moreover, the Government favoured it with beneficial fiscal horsepower figures, encouraging more and more ingenuity from engineers. Thus we’ve ended up with motors that seem remarkable when compared with those that you’d have found in a Peugeot 405 GRD of just 25 years ago. This is where the considerable talent of the French industry has been concentrated, and it has led the World, but I’m not sure that history will thank them for this.
Because a PSA XUD7 1.8 litre 4 cylinder diesel is not a great looker, this piece is largely illustrated by grand engines from France’s distant past. These impress in both specification and appearance, especially when buffed up to Pebble Beach standards, but they were always intended for a select and wealthy minority. To produce engines for everyman is a more worthy task and, on many levels this is what France has done. However their emphasis on oil-burners means that, in my eyes, it is Italy and Japan who take the honours as the great small engine manufacturing nations.