Fragments On Forgotten Makes No. 43: THE IMPERIA
EVEN prior to the First World War the Imperia from Liege had sporting connotations. It had been raced on the Continent and inevitably cars of this make appeared at Brooklands. In 1908, for example, a lady achieved some notoriety, at a time when females were regarded as very much the gentler sex and were not permitted to compete in races on the new Track, by covering 53 miles in an hour at the wheel of an 18cv. Imperia. Later a 4.6-litre model was able to lap at over 75 m.p.h. This Belgian make was by then represented in this country and enthusiasts with inside knowledge must have been at least mildly excited when, after the Armistice, Imperia decided to follow the example of Mercedes with their invincible 1914 GP racers, and make a car with single overhead camshaft and four valves per cylinder.
However, this sporting Imperia was shoe-lived. It had been conceived at a time when the poppet valve was suspect in some circles and designers and inventors were busily turning their thoughts to getting rid of it, prompted perhaps by the lead given to them by the Royal Daimlers, made by a pioneer British Company that had eschewed noisy poppet valves from the year 1909, in favour of Mr. Knight’s silent double-sleeves. It could be argued that some great companies, like Panhard-Levassor, Mors, Minerva, Voisin, Piccard-pictet and Willys in America, had followed the Daimler example, while others had banished the poppets by adopting the Burt McCullum single-sleeve valve, like Argyll and Arrol-Aster, and which Vauxhall of Luton were about to try. In Belgium, where the Knight-engined Minerva ruled supreme, Imperia came up with a solution all their own, in the form of a slide-valve ettgine. I have described this as following steam-engine practice, but whereas such valves are then located in a separate steam-chest, those in thr InTeria engine, which was designed by the Company’s Chief Engineer, Arnold Couchard, were situated within the cylinders, between the Pamoss and the cylinder walls, sliding in dovetailed grooves. In this they werc not far removed from sleeve-valves, except that they did nor completely encircle the piston, and they ntotProcated only, instead of having a combined ol.and-down and semi-rotary movement. These slide valves were operated by double cams that weret_ surrounded by, and activated, levers that ,,__.cressed the cam-lift. The action was ..sotairomic, as there were no valve-springs
At this time — the first of these slide-valve Imperias had reached the Belgian market by 1923 — not only was there this move afoot to banish the conventional poppet-valve, but much interest was being taken as to how the gases should be persuaded to flow within the combustionchambers, before ignition took place. Riccardo, Whatmough and Weslakc were propounding different theories, from “squidge” to turbulence. It seems that Couchard preferred the latter, because each of his inlet slides had two slots, or ports, at its upper end, so that the gas had two “bites” at entering the cylinder, this giving a turbulent effect.
Although Imperia had been building some large engines, including an o.h.c. straight-eight, the young Managing Director, Mathieu Van Roggen, saw the future as belonging to smaller cars and the first of the slide-valve engines was a one-litre 63 80 mm. four-cylinder, of which the prototype is thought to have been tested at Brooklands, driven by Van Roggen. When production began, in 1924, the sire had been slightly increased, to 66 80 mm., putting the ingenious Impala into the 1,100 cc. class.
It wasn’t until late in 1924 that the first of these slide-valve Imperias came to Britain. At what historian Michael Sedgwick calls the “jam Factory”, at Maidenhead in Berkshire, the friction-drive GWK light-car, once so successful, had fallen on hard times. A. G. Grice, the “G” of GWK, had forsaken the venture to make his Unit No. 1 friction-drive small car at Wooburn Green and after the transfer of the GWK works from Datchet to the Corwallis premises at Maidenhead, GWK sales had fallen off. However, Grim returned to GWK, being joined on the Board by an old friend, Mr. Van Roggen, with whom he had allegedly been about to produce acne when war stopped their plans. Lord Montagu has it that this was Mr. M. A. Van Roggen. But a reader of MOTOR SPORT, Mr. Leslie C. Stead of Ashburnham, who has kindly allowed me to make use of his memories of working at the “Jam Factory, at the relevant time, remembers this gentleman as Mr. G. R. Van Roggen, a brother, perhaps, of the MD of the Belgian Imperia factory? It seems unlikely that such an important member of the parent Company would have come to England so soon after the new model had been launched, especially as Paul Frere, the celebrated motoring journalist
and historian, whom I consulted and who has also kindly helped with these “Fragments”, says that Mathieu Van Roggen later became a leading figure in the Belgian Motor Industry (although he died completely ruined, two years ago). It seems more likely that he sent another member of his family, a brother perhaps, to try to establish the Imperia in this country. This ties in with Lord Montagu telling us that this person had been a marble merchant in Belgium before the war, whom Once had got to know by selling hint bandsaws Purina business. Whatever the truth of this, the fact is that Grice was persuaded to use his Corwallis factory as a base for imported slide-valve Imperias, as well as trying to sell GWK light-cars. Mr. Stead remembers Mr. Van Roggen as a rather silent, aloof man, who never betrayed much feeling about anything, which would seem to tie in with someone sent on a not very promising project, to a foreign country, maybe against his will, Mr. Stead says that after the idea was mooted a curious suspense fell over the Corwallis works and although the project was talked of for more than a year, neither Grier nor Van Roggen seemed to take it seriously. New radiator badges lettered “Imperia-Maidenhead” instead of “ImperiaLiege” were ordered and a draughtsman was brought in to design a four-seater tourer body for the Imperia chassis. But only one such body was actually made. “It was completely unattractive”, recalls Mr. Stead, “the doors raked at an angle that did not match the rest of the body, which looked heavy and was finished in a battleship grey; I couldn’t imagine anyone buying it and I
awe sure the making of it must have caused old Mr. Nash, the GWK body-shop foreman, much
At the 1924 Olympia Show, a touring 10/24 h.p. Imperia was shown cm the GWK stand. In spite of its 1,095 c.c. engine. the wheelbase measured 8′ 101/2 “, so the body was commodious, and as the slide-valve engine had the good pulling power and smooth-running of a sleeve-valve power unit and did not have valve-settings needing to be frequently adjusted, there might have been a market for the Imperia, at £375 (a GWK four-seater then cost E255), especially as it possessed mechanical-servo front-wheel and transmission brakes. Michael Sedgwick, however, has likened these Imperias to a “slightly down-at-heel Panhard-Levassor in miniature”. Sales were to be handled by W. G. Nichol! Ltd., with premises at Leicester Square Garage in London’s Whitcomb Street, WC2, Mr. Nicholl being a Director of the Maidenhead concern. The venture seems to have been doomed from the start. Mr. Stead says that no tooling-up or spares-stocking was done, or even a store of imported parts established, nor was any attempt made to design a body acceptable to British eyes. In the months before the Show, only one chassis came to Maidenhead. No exhibit was forthcoming for the 1925 London Motor Show. Yet in its native country the slide-valve Imperia seems to have been doing well for its makers. Paul Frire tells me that 250 were built in 1925, 420 in 1926 and 504 in 1927 rising, I believe, to 1,440 by 1928 and over 2,500 in 1929. (Incidentally, his first can was one of the rare six-cylinder three-carburetter Grand Sport Imperias, with the shorter-wheelbase four-cylinder chassis, Rudge wheels, equipped with just a couple of bucket seats and a spare wheel, which he bought for the proverbial “fiver” after it had been involved in an accident and rebuilt during the war. He also had an uncle who ran a 1926 four-cylinder 1,100 cc. Imperia with a Matthys & Osy coupe body, these being quite popular in Belgium. The saloon bodies were made at the Imperia factory.)
By 1927 a six-cylinder version keeping the same bore and stroke dimensions was introduced, giving a capacity of 1,650 cc., and two years later the bore of this engine was enlarged to 69 mm., so that the capacity was increased to 1,800 c.c. Inns age when small sixes were the vogue, Imperia were well in the hunt) These latter small sixes were shown at Olympia from 1926 onwards, often with leather-covered bodies in striking colours, and the British motoring press received cars for road-test. For example, the Autocar tried a heavy low-geared (5.1 to 1) 11 h.p. tourer (Reg. No. X1X/ 1845) in 1924 and an 11/24 h.p. fabric sunroof saloon (Reg. No. YR 3613) in 1926, the latter thought undergeared and noisier than most sleeve-valve-engined cars. Even The Times was permitted a brief trial of one of the first 11/24s to come over here, this hard-used tourer with English bodywork being found generally satisfactory and its clutch and gear-change being warmly praised. It had the 5.1 to 1 wile-ratio, giving a top speed of about 50 mph., but a 5.5 to 1 ratio was available for all-on-top addicts. The writer criticised only the design of the exhaust manifold, wrongly shaped he said for use with slide valves, causing a drumming sound, and the heavy steering. Otherwise the four-speed E450 Imperia got warm praise from “Auntie”. Frere estimates top speeds as being 50-53 m.p.h. for the four-cylinder, 62-69 for a touring Six, and 75-78 for a GS Six. Obviously, attempts were being made to sell the
cars here. Van Roggen drove a Belgian-registered saloon with full complement of passengers from the Glasgow starting-point in the 1925 Monte-Carlo Rally, winning his class, with Lansival and Klink, who had started from Brussels, second and third, and the sporting connotations of the marque were endorsed when a GS Imperia finished third in the 1,101-2,000 c.c. class of the Spa 24-hour race that year. Another fine performance had been in the 1930 Belgian GP, run on a fuel-consumption basis. Imperia prepared four virtually standard GS models for it, one as a spare car, with lightened chassis, racing bodies and more highly-tuned engines each fed by site Amal carburetters. Geoffredo Zehender and Jacques Lcdure drove them into fifth and seventh places. Paul Frere used to see one being used on the road around Brussels up to the outbreak of war. The Imperias entered for the 1936 Spa Ten Hours Race, with insufficiently developed new four-cylinder engines, all retired, and the slide-valve concept was finally abandoned. Yet, as Mr. Stead recalls, down at Maidenhead not much of this was evident. Presumably W. G. Nicholl Ltd. sold most of the slide-valve Imperias that found English customers, who apparently lived mostly in and around London. The London depot had had a demonstrator since September 1924 and in 1925 H. J. Pope, who had been a very successful works driver for GWK, took an Imperia through the MCC Land’s End Trial, winning a silver medal, having previously gained a gold in the London-Exeter Trial. That summer, Van Roggen became Managing Director of the Corwallis works and, presumably under his initiative, sales brochures and picture-postcards of Imperias, carrying the Maidenhead address, were prepared, despite no visible changes being made at the factory,
Following a resumption of exhibiting at the Motor Show, where a sectioned engine showing how the slide valves functioned was part of the display, the name GWK Ltd was changed to Imperia Motors Ltd. in December 1926. R. G. Jackson, Service Manager and Acting Sales-Manager at GWK’s, was made Sales Manager of the new Company. His reward was to be sent to the docks one cold winter’s day to collect one chassis, which was brought to Maidenhead robe fitted with thc four-seater body which had been made there, and an “Imperia-Maidenhead” radiator badge. By 1929 it was all over for Van Roggen, who by that October had ceased to be MD of the Corwallis venture. Did he return to direct Ins Belgian Company (which was to absorb the last of the once-great Minerva Empire, as well as Excelsior. Mitallurgique, and Nagant, and then to make German f.w.d. Adlers under licence) or was that a lesser, less-successful member of the Van Roggen family?
Whatever the answer, while he was at Maidenhead Van Roggen had a house by the river below Maidenhead bridge and the Imixria he used, a lavender-coloured steel-panelled saloon, was in tip-top condition. Mrs. Van Roggen would have it washed and polished by one of the Service Department lads. Otherwise, it was seen only occasionally, but it had quite good performance. On one long drive across England, a Service Department mechanic failed to keep up with Van Roggen and stayed overnight at a tavern; the next morning emerging from the customary aloofness, Van Roggen sacked hun immediately after his arrival. Another works car was used mainly by Col. Lucas; it was a red sports four-seater, with a loud exhaust note. But after a high mileage it was
rather low on power. This was the Imperia mos, frequently seen parked in front of the Company offices. There was also a well-worn sports two-seater, seen but seldom at the “Jam Factory. and probably based in London. Apart from those, and the first chassis to which the Maidenhead-made tourer body had been fitted, and a saloon with the Maidenhead badge sometimes seen parked in Maidenhead around 1930, those were the only Imperias that Mr. Stead ever saw there.
The slide-valve engine most have been expensive to make, but it was reliable and capable of sustained high r.p.rn., even in a fairly-worn state. But as the slides suffered from increasing wear, power would fall off badly. This produced the amusing sight of Col. Lucas, when driving his old sports-model up the Bath Road towards London, changing down into third gear and • letting the engine rev, up with an awful shriek in his unsuccessful endeavour to get away from the works-demonstrator 1925 GWK with its 4.5 to 1 top gear, which nevertheless would slowly overtake the faster-looking Imperia. . .
After Van Roggen had turned it in, Alfred W. Dungan carried on for a time, but he was more interested in forming the present Trading Estate on the Maidenhead site and after 1930 the Imperia ceased robe in the news at the Motor Show. Not many could have been sold here, in spite of some examples, such as the little Vanden Plan coupe, having had quite nice lines. All that remains into thank Mr. Stead and Paul Feline for their help with this article and to wonder if anyone else has any memories t.,1 this unusual car? — W.B