Cars, General, History, People, Technical

Bristol 400 by Jonathan Wood

Jonathan Wood looks at the first of the distinguished Bristol line, the 400. This was a pre-war BMW in all but name, with its 326 chassis, 328 engine and 327-derived body.

Top: A 400 is dwarfed by the Bristol Brabazon at Filton in 1947. The transatlantic airliner first flew in 1949 but was cancelled in 1953 for financial, political and technical reasons. Above: H J Aldington (right) is seen here with Count ‘Johnnie’ Lurani at Filton with AFN’s 400 demonstrator. They drove this car in the 1949 Mille Miglia and were placed 13th overall and third in the touring car class

It was, in retrospect, an extraordinary decision. In 1945 the Bristol Aeroplane Company decided to enter the automobile market and produce a car “hand built for the connoisseur” made to aircraft quality standards of materials and inspection. Amazingly, the firm was to produce as much of the car as possible at its Filton factory, a practice which echoed British manufacturing methods current in those balmy days before the First World War.

But rather than design one from scratch, Bristol drew on established concepts, namely those of pre-war BMWs. Deliveries of the first of the line, the 400, began in 1947, a mere two years after the ending of the Second World War.

Bristol had begun building aircraft before the previous conflict, in 1910, its first chairman being Sir George White Bt. In 1920 it had been encouraged by the Air Ministry to take over the local Cosmos Engineering because its chief engineer, Roy Fedden, had designed an aero-engine with great potential, namely the big nine cylinder Jupiter radial. It paved the way for the Perseus of 1932, the first of a succession of mighty sleeve valve radials, which were to consolidate Bristol’s global reputation. At the time of the outbreak of the war in 1939 the company’s aero-engine division was the largest facility of its kind in the world. 

The company’s interest in diversifying into the motor industry dated from these prewar days. The idea may have taken root back in 1920/24 when Bristol bodied some 30hp chassis for fellow aero engine manufacturer Armstrong Siddeley. In the early ’30s it considered buying Aston Martin and, in October, 1941, set down its thoughts in a ‘post-war planning’ document. The type of cars envisaged ‘would have a six-cylinder engine of two to 2.5 !itres capacity.’ Some Continental manufacturers were singled out as examples to follow, namely Lancia and BMW. ‘These cars were ‘designed’ in the best sense of the word,’ the document went on. ‘They are not merely ‘assembled’ as so many British cars may be considered to be.’

George Stanley Middleton White, grandson of Bristol’s founding father and heir to the baronetcy, was 32 years old in 1945. He and his cousin, Reginald Verdon Smith, both enthusiastic motorists, were to share the managing directorship of the Bristol Aeroplane Company. White, an Old Harrovian, had read engineering at Cambridge, and as the prime mover in the project headed the newly established corporate Car and Light Engineering Divisions.

To the distinguished former Rolls-Royce engineer, Dr Stanley Hooker, who arrived at Filton in January 1949, his recollection of White was of “a happy-go-lucky chap who indulged his favourite hobby with the Car Division and left the main business to the ‘Headmaster’ as he called Verdon.”

Top: George White, who conceived the idea of a Bristol car, with a scale model of the 400’s successor, the 401, on his desk in 1952. Above left: The first 400 and therelore the first Bristol, completed in 1946 and owned by Anthony Crook, the company’s former owner. This car features bonnet air intakes that were not perpetuated on the production versions. The BMW-derived engine is on the right. Above right: An advertisement for the 400. Note that this example has the spare wheel mounted externally, a modification introduced early in 1948

A justification for the project was an attempt to anticipate the commercial vacuum that had struck aviation in the years immediately following the end of the First World War. The mass production of pre-fabricated houses was another although diametrically opposed diversification. As it happened the post 1945 era was to see a dramatic growth in aircraft sales and, mostly thanks to Hooker’s efforts, Bristol embraced the jet age.

The 400 had already entered production at the time of his arrival and the fact that the car was BMW-based came about largely through serendipity. As is well known, AFN Ltd., was owned and run by the Aldington brothers, the key players being Harold John, better known as “Aldy”, and Donald Arthur or D.A.

The distinctive but ageing chain-driven Frazer Nashes had since 1930 been produced in limited numbers at AFN’s newly opened Falcon Works in Isleworth, Middlesex. But from 1934 AFN imported the products of BMW, then one of Germany’s newest car makers, and marketed them under the Frazer Nash-BMW name. It was an association which underpinned H.J.’s veneration for that country’s automobiles and the engineers who designed them.

 This activity was cut short by the outbreak, in 1939, of the Second World War. The brothers then joined the Royal and Mechanical Engineers, H.J. as a lieutenant colonel and Don a captain, but the latter was involved in an accident in his Singer Le Mans and he was invalided out of the army. Joining the Ministry of Aircraft Production as an engineer-inspector, Don was posted to Bristol, with offices in the city. Keeping his ear to the ground, he heard of George White’s ambitious plan to enter the post-war car market and wasted little time in informing his brother.

H.J. duly arrived at Filton at the wheel of a BMW 327/80 coupe. This desirable model had started life in 1937 with the 326’s 2 litre engine but this variant, introduced for the 1939 season, used the potent power unit from the 328 sports car. Capable of a spirited 87 mph with acceleration and handling to match, a total of 580 examples had been built, either in cabriolet or coupe form. Both were the work of Darmstadt coachbuilder, Autenreith, styled with great vitality by its designer Franz Truby.

George White, much impressed with the 327/80, declared that it was precisely the sort of car he had envisaged. From his standpoint Aldington was also looking to secure Frazer Nash’s post-war production and to these ends in July 1945 Bristol took a majority shareholding in AFN. Verdon Smith became its chairman and H.J. managing director.

The war in Europe had ended in May and Aldington, still in uniform, soon made his way to Munich which was where BMW’s aero engines and motor cycles had been manufactured. However, Eisenach, home of BMW cars, was now over the boarder in East Germany. The purpose of Aldington’s mission was to retrieve his prototype 328 that he had crashed at Hamburg 1939. Although unable to find his car, at the suggestion of an old friend, BMW’s sales director Fritz Troetsch, he secured an even greater prize, one of the BMW-styled but Touring-bodied 328s prepared for the 1940 Mille Miglia race. This vehicle was to represent the starting point of a new generation of Frazer Nash sports cars, a concurrent development which falls outside the scope of this study.

As far as the Bristol car project was concerned, Aldington made a subsequent visit to Munich in 1945, this time in a Stirling bomber, to retrieve six BMW engines, confirmed in a BWM delivery note dated August 31st, together with blueprints for the 326, 327 and 328 models. Lest it be thought these were “liberated” amongst the spoils of war, Rainer Simons in his masterly study of the BMW 328, “BMW 328 From Roadster to Legend” reveals that “in compensation quantities of cash in English currency were sent to Munich…These funds, handed over discreetly, were set aside by BMW for essential working equipment for the plant”.

Filton now possessed the building blocks of a car but, despite its formidable financial and engineering resources, the company required engineers with motor industry experience to bring it to production. In June 1945 H.J. Aldington had recruited John Perrett to be Frazer Nash and Bristol’s chief designer, although the latter was to spend more of his time at Filton than Isleworth, making the journey at the wheel of the Mille Miglia 328. A graduate of the Regent Street Polytechnic, Perrett had worked at Thomson and Taylor under Reid Railton, then MG with Hubert Charles and next Vauxhall. Later becoming chief designer for Robot Engineering, he joined Vickers and arrived at Isleworth via the Fighting Vehicles Research and Development Establishment at Chobham, Surrey.

At Filton George White made Major George Abell, formerly head of Bristol’s armament division, manager of the Car Division. Crucially he had a motor industry background, having begun his career as an engine tester with Maudslay in Coventry before joining Sheffield-Simplex in a similar role. Prior to being joint managing director of Invicta Car Sales, he had had run Connaught coachbuilding so his knowledge of both bodywork and mechanicals made him well qualified for the position.

News of the project had been made public in August, 1945. Preliminary details of the design were issued in April, 1946, and the first Bristol built engine was running in May. It was then installed in Verdon Smith’s own 1938 327, JHX 338, modified to 80 specification in 1939, which proved highly satisfactory. The engine, however, developed 100bhp which was thought to be excessive; 80bhp was deemed sufficient for the production version. In September, 1945, Bristol decided that 250 saloons and the same number of drophead coupes would be produced, selling for 1000 and 1050 pounds respectively. The new car had been provisionally designated the 400/85, to reflect that it was succeeding BMW’s prewar Series Three and its anticipated horsepower. When the German company restarted car production in 1951, its two litre model was titled the 501, so underlining the Bristol as a BMW design.

A year on, in September, 1946, details of what was described as the Frazer Nash-Bristol were revealed in the motoring press. Perrett was responsible for laying out the mechanicals, while at Bristol body design was entrusted to Dudley Hobbs, who in 1949 would become chief designer. Hobbs had learnt his engineering at the city’s Merchant Venturers Technical College, joined Bristol in 1928 and was well versed in the science of aerodynamics, having been responsible for the wing design of the Beaufort reconnaissance torpedo bomber and of the Beaufighter.

The starting point for the 400’s body was the Autenreith coupe although it should be said that Aldington and White had disagreed over the use of the design. Despite its undoubted elegance it was in essence a pre-war concept, with separate front wings and running boards.

For his part H.J. had advocated the latest Italian styling and a concession was to be drophead coupe versions of the 400. One was built for AFN in 1947 by Pinin Farina “for export only” and another was by Touring which also produced an aerodynamic saloon to its Superleggera principles. The latter clearly anticipated the Touring-styled but Bristol licensed and refined 401, which effectively replaced the 400 in 1949. But by then AFN and Bristol had gone their separate ways, So White’s view held sway. The 400’s body, which reflected use of the Filton wind tunnel, was a two door coupe, unmistakably BMW at the front with its familiar twin oblong grilles. It followed the traditional composite coachbuilt construction being a timber frame clad with steel panels although the doors, bonnet and boot lid were made of alloy.

Inside a wooden dashboard replaced the BMW plastic one, the angular instruments finished in black with white numerals. There was an HMV radio although a heater was available at extra cost. To allow for extra elbow room the driver’s and passenger’s windows were sliding rather than winding. On later cars the material was extended to a hinged  rear view window which could be opened by a crank. The Autocar was to reflect that the interior gave “something of an impression of an aircraft cabin.”

But the rear seating in the 327/80 was severely restricted so the 400’s chassis was instead based on that of the 326 which, with a wheelbase of 9ft 6in, was six inches longer. Destined to be the best selling BMW of the decade with some 7000 produced, the 326 had a substantial box section frame, designed to counter the flexing of its predecessors’ tubular chassis. At the front independent suspension was by transverse leaf spring and wishbone, an inverted version of that used on the earlier sports 315. Rack and pinion steering was similarly carried over although hydraulic brakes made their debut on the 326.

The rear suspension was another matter. BMW’s chief designer Fritz Fiedler based at Eisenach had been much impressed with the Porsche-created all independent torsion bar system used on the Mathis Quadruflex. He was similarly influenced by the layout of the torsion bars on the 1934 Traction Avant Citroen. So the BMW ended up with a live rear axle sprung by longitudinal bars contained within either box section and connected to it via hydraulic dampers. Bristol was to manufacture these although, in due course, they were replaced by Newton & Bennett units. Side movement was checked by A-brackets.

When it came to the Bristol’s engine, Aldington had returned from a visit to Munich bringing news of an experimental 72 x 82mm 2 litre twin overhead camshaft engine. This was the 318 unit, intended successor to the 328. Yet another of his initiatives was the 3½ litre unit which powered the 335 of 1939, but enhanced with a 328-type head. However, the case for using the 2 litre 328 six was overwhelming, it being readily available and, above all, a proven commodity.

Cross-section of the Bristol engine’s cylinder head in 1946. Essentially the prewar BMW 328 unit, it featured triple SU carburetters in place of the original Solexes

Back in 1935 Fiedler’s colleague, the Munich-domiciled Rudolph Schleicher, driven by BMW’s limited financial resources, decided on a new cylinder head but one to be mounted on an existing six cylinder block.

BMW engineer Rudolf Flemming played a key role in the design which combined the attributes of a hemispherical combustion chamber and inclined valves with the side mounted camshaft of its 319 predecessor, rather than the more costly twin cam layout. While the inlets were actuated conventionally by pushrods the exhaust valves were motivated via rockers to short pushrods enclosed within stubby tubes which ran across the aluminium cylinder head. This necessitated vertical inlet tracts fitted with triple Solex carburettors. The net result of these ministrations was a potent, if rather high engine, with internal dimensions of 66 x 96mm and a capacity of 1971cc. In its original form it developed 80bhp at 5000rpm, endowing the 328 with a top speed of over 90 mph.

Bristol’s BMW 328-derived engine powered all Bristol cars until 1961 and was also made available to other manufacturers. It is shown here in the 400’s successor, the 401

The Bristol’s engine closely mirrored the 328, although some changes were made. Sparking plugs were now 10mm and alterations were made to the camshaft and carburation. Triple SUs, by all accounts at Aldington’s insistence , were fitted to the power unit designated Type 85A, and the overwhelming majority of 400s were so equipped. However, a significant number used tripIe Solexes in the BMW manner. Some cars were subsequently converted and today there is about a 50/50 split.

BMW had not built the 328’s four speed gearbox, it being a ZF unit, replaced by a Hurth component in 1938. Bristol copied the Hurth and unusually, the casing was split vertically rather than horizontally. Synchromesh was used on the top three gears, first having straight cut gears and used in conjunction with a freewheel. Drive was conveyed to the rear axle via a split propeller shaft.

Top: One of the rare 400 cabriolets; there were only two with factory coachwork. This example, owned by Andrew Blow, graced Bristol’s stand at the 1947 Geneva Motor Show. Above: The other factory-bodied 400 cabriolet (003) at Filton early in 1947, with 004 under construclion in the background

Just four pre-production examples of the 400 had been built. Cars 001 and 002 were “test driving chassis” to be bodied as saloons while 003 and 004 were open versions and listed as prototypes. Two examples, a saloon and factory cabriolet were completed in time for the 1947 Geneva Motor Show held in March. However, the following month the agreement with Frazer Nash was unscrambled, its name dropped and the cars sold solely under the Bristol moniker and the open versions discontinued. A collision between Isleworth and Filton was an accident waiting to happen. Apart from the disagreement over the 400’s body, HJ and the quietly determined George White came from differing cultures, both social and commercial. Aldington, a product of the west London motor trade, was used to thinking on his feet and making swift decisions.

The Bristol board of directors, by contrast, was accustomed to more measured deliberations and although, from their standpoint, they had moved rapidly enough, H.J. felt that the project was progressing too slowly. And his belief in the superiority of German engineers over English ones had not gone down well at Filton so soon after the ending of the war. At Bristol they believed Aldington’s lack of manufacturing knowledge and impetuosity would be to the detriment of the finished product.

So after 19 months, control of AFN reverted to the Aldingtons. But despite the corporate rift, Bristol continued to supply engines and gearboxes for the post war generation of Frazer Nashes, a limited line that began in 1948 and survived, latterly in BMW V8-engined form, until 1957.

The first 400s began to leave the factory in mid 1947 by which time the car’s price had risen appreciably to £2373. A doubling of purchase tax on models costing over £1000 from January 1948 saw the Bristol soar to £2723, making it some two and a half times more expensive than, for example, Jaguar’s new 2½ litre Mark V saloon. Yet despite this price handicap the 400 was destined to sell some 425 saloons by the time that production ceased in 1950. There were another 20 or so non-standard examples. Of this total a significant number were exported. The Bristol Owners’ Club of Australia has identified 78 cars so designated. Other overseas markets were a long way behind; America took only three and such countries as Belgium, France, South Africa and South America imported a brace of 400s apiece.

The Bristol therefore emerged as one of the handful of new British marques to appear after the Second World War. Bearing in mind that work on the project had only begun in 1945, this was remarkable achievement, particular in an era of shortages and governmental red tape. Practically all of the car was built in-house, an advantage not enjoyed by any other motor manufacturer.

The special nature of the Bristol’s facilities was underlined by John Dugdale, writing in The Autocar following a visit to Filton late in 1947. He reported: “the only major components not made by Bristol were the Lucas electrical equipment, the Borg and Beck clutch and Lockheed brakes, the propeller shaft and tyres…When difficulties in construction or research are met, consultation with their own aircraft division can often provide a rapid solution.”

Taking the wheel of a 400, Dugdale was much impressed by the car’s “excellent road holding”. It had “become a cliche to refer to accurate steering over the proverbial sixpence, but the Bristol can be placed with exactness when cornering, probably because of the effectiveness of the independent front wheel suspension.” He was equally impressed with the ride which was firm but not harsh. With four passengers aboard “85 mph was reached easily”, and in a subsequent road test the magazine found the Bristol was capable of over 90mph.

Dugdale did much of his evaluation at night and praised the 400’s powerful headlamps. With “the car radio and heater operating, long distances were driven tirelessly.” He concluded that “without doubt the Bristol Aeroplane Company at the first attempt had produced an outstanding British car.”

A few changes to the specification were made during the three and a half years of production. After about 35 cars had been delivered, in January, 1948, the original tubular bumpers, aesthetically pleasing but ineffectual, were replaced by more conventional pressed steel ones. Perhaps at about the same time the carrying capacity of the boot was enlarged, the floor was dropped, and the spare wheel was removed and mounted externally on the lid. Its top mounted hinges were now relocated at the base.

In view of the 400’s sporting pedigree it comes as no surprise to find that owners used their cars in competition. A victory in the 1948 Polish Rally, driven by the Czechs Dobry and Trybal, was followed by another success; they were placed third in the 1949 Monte Carlo Rally. In the same year Bristols ran in the Targa Florio, Alpine and Mille Miglia, the best result being Aldington and Lurani’s third position in the latter. Lurani also drove a 400 to victory in the touring car class in the Coppa Toscana. 

Czech drivers Treybal (Ieft) and Dobry, who were
placed third in the 1949 Monle Carlo Rally in their
Bristol 400. It was the first British car home

In November 1948 the 400’s successor, the roomier 401, made its appearance although the first Bristol model continued to be built into 1950. The BMW-derived engine was destined to survive until the demise of the 406 line in 1961, to be replaced by a Chrysler V8.

Bristol survives today, its association with its Bristol Aeroplane parent having been severed in 1960, as one of a handful of makes which, happily, remains in British ownership. (Note: this was the status in 2009 when the article was first published!).

The assistance of Dr Stefan Cembrowicz, Andrew Blow and the Bristol Owners Club in the preparation of this article is much appreciated. And where would we be without From Chain Drive to Turbocharger, Denis Jenkinson’s unravelling of the AFN story? With thanks to Charles Oxley’s Bristol An Illustrated History, BMW: A History by Halwart Schrader and Sir Stanley Hooker’s Not Much of an Engineer.

(Note: This article is reproduced by kind permission of The Automobile where it was originally published in Sept. 2009)

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