Great Day for a Great Car

The Mercedes-Benz W165 1939 Tripoli Grand Prix Cars

Article Graham Robson

Images Daimler Archives

On September 11, 1938, Mercedes-Benz’s motor-racing boss, Alfred Neubauer, suffered a severe shock to his company’s prospects. Not only had Mercedes-Benz just failed to win the Italian Grand Prix at Monza, but without warning he was informed by the Italian motorsports overseers that starting in 1939, all future single-seater GP races in Italy were to be for supercharged 1.5-liter-engined cars. The first of these events would be held in Tripoli, in the Italian colony of Libya, on May 7, 1939, and other races would soon follow.

Neubauer and his colleagues were aghast. Since 1934 their Silver Arrows – with progressively larger, more powerful, and faster engines – had become more and more dominant in Grand Prix racing. Now it seemed that for 1939, Mercedes-Benz would not possess a single-seater eligible to race in Italy and its colonies. The Italian constructors – specifically Alfa Romeo and Maserati – were delighted, for the new rules had been laid out precisely to favor them.

Tipping the balance

A moment, though, to fill in the background: When Mercedes-Benz and Auto Union entered Grand Prix racing in 1934, motorsports changed shape completely. The new set of regulations which took effect that year – known as the “750kg rules” – encouraged competitors to produce larger and more powerful engines than ever, to use lighter and more exotic materials than ever, and to push the boundaries of engineering technology to new heights. Before long, it was the cars, team and practices of Mercedes-Benz that became supreme; by 1938, it was setting every standard in the sport.

Almost every other brand hated the way the scales had tipped so far in favor of German engineering and abilities, but it was the Italians and French who suffered the most. In the 1920s and the early 1930s, companies such as Bugatti, Delage and Alfa Romeo had been dominant. Now they were struggling.

Accordingly, the sport’s governing body tried to tip the balance a little and imposed a radical regulation change in 1938, limiting engine sizes and power outputs. But this did not have the slightest effect on the balance of sporting achievement. Mercedes-Benz’s latest Grand Prix car was the W154, with a supercharged 3-liter V-12 engine producing 450 horsepower. It would instantly be a winner. More of the same was known to be on the way for 1939, leaving Italian rivals terrified at the prospects.

The immediate forecast of the Italian rules change was that the latest Italian voiturettes (from the French term for small car) would dominate 1939 racing. Except that Mercedes-Benz – though not, significantly, Auto-Union – had other ideas.

 A plan takes shape

Only days after Neubauer’s shock, he attended a meeting back in Germany where his team was asked, quite simply: Could they produce a competitive supercharged 1.5-liter-engined racecar before May 1939 if the money and facilities were made available? Initially, the cautious and pragmatic German engineers thought not, but they were overruled and directed to start at once. In November, the new project – now coded W165 but still highly secret – became official. Nowadays, one might suppose, it would be difficult, if not impossible, for security to be maintained. But in 1938, it seemed that no one – not even Auto Union, which had concluded that it could not react to the Italian move – realized what was going on.

At this stage, I should emphasize that alongside building the secret W165, work was still going ahead on improving the existing 3-liter W154 Grand Prix car for the 1939 season, that new record cars were under development, and that first thoughts had already gone into producing a land-speed-record car. With all the other new machines being designed, the pressure on chief engineer Max Sailer’s team to succeed must have been immense. I must also stress that there was so much basic difference between the existing 3-liter W154 racecar and the requirements for the new, smaller single-seater, that there was no question that any existing hardware or chassis could be used to save time and expense.

Building the W165

So this was the moment when a good – if rather extreme – idea was set to turn into one of Mercedes-Benz’s greatest achievements. In only seven months – a breathless rate of progress by any standard, and something that the race team had never before attempted – a good idea was about to become a great accomplishment. Looking back, this was the first time since 1922 that the team had developed such a small-engined car, the very first time they had developed a state-of-the-art V-8 engine, and the first time that pre-event testing would not even begin until the month before the race itself.

According to the meticulous records Mercedes-Benz kept of the W165 project, the entire design was completed by 10 individuals working under the direction of passenger-car design chief Max Wagner and engine designer Albert Heess. The layout of the first major castings was finalized before the end of 1938 and the first car began to take shape early in the new year. The intention was to build only two complete cars (plus a very few extra components and sub-assemblies as spares) so that circuit testing at Hockenheim could take place before the W165s, in a caravan of works trucks, could set off by road from Southern Germany all the way through Italy to pick up a ferry across the Mediterranean and get the cars to Tripoli, on the African coast of that sea.

For the next six months, what we might call “Mission Impossible” today was continuously unrolling, for time was always against the endeavor, and it would have needed only one major setback for the whole scheme to collapse. But that never happened – in many cases because the designers never tried to adopt new techniques that had not already been proven on the larger racecars that were taking shape just a few yards away. The family likeness was so striking, that when the two types of cars were posed next to each other, the W165 just looked as if it were a W154 that had shrunk in the wash!

It was almost as if the W165 had grown organically from the W154 Grand Prix cars, of which the company was so proud. The same basic layout was chosen, many similar components and systems were adopted, and in many ways the new W165 gradually took on the same sleek single-seater lines of the W154. And why not? The use of a front-engine/rear-drive layout in a tubular-chassis frame, with a gearbox mounted in unit with the rear axle, with independent coil-spring front suspension, and with torsion bar springs supporting a De Dion rear layout were all recognizably related to what was already featured in the W154.

But not the new M165 90-degree V-8 engine. This, by any standard, was a total novelty for Mercedes-Benz; the company had never engineered a V-8 engine. Such layouts, of course, were featured on rival racecars, but for years Mercedes-Benz had concentrated on straight-eights (including the fabulous W125), and V-12s (used in the W154 and several contemporary record cars). Even so, for a new 1.5-liter racecar, the W165 looked ideal for the company’s purpose; study of the cross-sectional drawings in the company’s archive makes clear that experience with the famous W154’s V-12 had been put to good use in the new W165 power unit. The valve-gear layout and the cylinder-head details were obviously related, as was the way in which the compact cylinder block was laid out.

But pause for a moment. The first test runs of this 1.5-liter M165 engine produced up to 246 horsepower, which looked puny when compared with the 455 horsepower developed by the 3-liter W154. And so it was: Today’s A35 AMG, for example, produces 300 horsepower from a 2.0-liter engine, and will keep on delivering this for 100,000 miles and more. But by late 1930s’ standards, it was class-competitive. Both the new Alfa Romeo Type 158 and Maserati’s new 4CL claimed more than 220 horsepower for their own power units, but this would clearly be out-gunned by what was being developed in Germany.

The 1939 Tripoli Grand Prix

When Mercedes-Benz arrived in Libya and was faced by a mass of Italian cars in the entry list (four Alfa Romeo 158s, four new works Maseratis and no fewer than 18 privately entered Maseratis), team members must have shuddered at the prospect, especially when the two drivers – Rudolf Caracciola and Hermann Lang – found that one Maserati was faster than they were in practice.

Cleverly, Neubauer had requested different specifications for the two W165s – Caracciola’s car having slightly lower overall gearing, which it was thought could help him tempt the Italian drivers to overstress their machines, and Lang’s car having longer gearing and a higher top speed, said to be 170 mph. This, incidentally, was probably done because Tripoli’s Mellaha circuit consisted of rather scruffy roads, with long straights and fast corners, and a lap length of eight miles. In 1938, when the race had been won by large-engined German cars, Lang’s W154 had recorded a lap of 136 mph. But in 1939, after spirited practice sessions, it was the latest streamlined Maserati driven by Luigi Villoresi that clocked three minutes, 41.8 seconds (131.6 mph), marginally quicker than Lang’s best effort in the 1.5-liter W165.

When the race itself was held, in hot and blustery conditions, there was still much foreboding in the German camp, for all their time-cheating accomplishments had begun to look too good to be true. Yet somehow, as in all the best fairy tales, the W165s sprinted away into the lead: The drivers did not fight one other unnecessarily and they soon outpaced all their Italian rivals.

At the end of the almost two-hours-long race, Lang had needed only one planned pit stop – for fuel and to change tires – before completing the race at 122.9 mph, beating teammate Caracciola by almost a complete eight-mile lap. 

Britain’s The Autocar magazine, usually so respectful of everything being achieved by the Silver Arrows in motor racing, did not cover this event in great detail, though it did comment that this was not only the fastest road circuit in the world (meaning, faster than both Monza and Indianapolis), that it was currently the most important sporting event in the Italian series (for Tripoli was a colony of that nation), and that a large lottery had been organized around it. However, The Autocar did stress that the W165s were the only non-Italian cars in the event, had dominated from start to finish, and completed the 245-mile race without seeming to have problems of any sort.

For the Italians, it had been a complete humiliation. Perhaps taking Caracciola’s bait, Villoresi had sprinted away from the start, but destroyed the Maserati’s transmission almost at once. Giuseppe Farina and his new Type 158 Alfa Romeo hung on to second place for just two laps before gradually fading away, and as for the mass of other Maseratis – they might just as well have stayed at home in Italy.

One-off wonders

Amazingly, this was the only occasion the W165s would race in 1939, for the team was far too busy winning the Grand Prix series with their remarkable W154s, and from September 3 – just four months after the Tripoli race – World War II broke out.

What happened then to the W165 racecars – three examples had eventually been completed – could make a fascinating article of its own, for it included putting them into safe storage (far from Stuttgart) for the duration of the war, the hazardous but successful effort to get them into neutral Switzerland in 1945, the attempts to race them at Indianapolis, the unsuccessful foray to Argentina in 1951, and a tentative, if soon abandoned, suggestion that they should enter the fledgling F1 World Championship in 1952. That, though, is another story for another day.

1939 Mercedes-Benz W165

TYPE: Separate tubular-chassis frame • Front engine-rear drive

SUSPENSION: Independent front (coil springs and wishbones) • De Dion rear (torsion bars)

STEERING: Screw and nut • No power assistance

BRAKES: Drum brakes front/rear • No power assistance

ENGINE: 1,495cc 90-degree V-8 • 246 hp at 7,500 rpm • Roots supercharger • Solex carburetors

TRANSMISSION: 5-speed manual • ZF limited-slip differential

WHEELBASE: 96.5 inches  •  WEIGHT: 1,582 lb

HOW DID THEY COMPARE?

MAKE: MERCEDES-BENZ       MERCEDES-BENZ       ALFA ROMEO

MODEL:                W165                     W154                          Tipo 158

YEAR:                    1939                      1938                              1939

ENGINE SIZE:     1,493cc                 2,961cc                        1,479cc

HORSEPOWER:       251                   455                                  225

WHEELBASE:        96.5 in                 107.4 in                           98.4 in

WEIGHT:                1,582 lb                2,150 lb                       1,367 lb

Illustrations

Hermann Lang crosses the finish line to win the 1939 Tripoli Grand Prix in the Mercedes-Benz W165.

The new racecar was designed and built in record time.

Although all the smaller machine’s components were unique, outwardly the W165 appeared almost as a scaled-down version of the W154.

Sleek lines hid an all-new M165 V-8 engine.

The Mercedes-Benz motor racing boss, Alfred Neubauer.

Race winner Hermann Lang and teammate Rudolf Caracciola, who took second.

ABOVE: At the start, Lang (No. 16) and Caracciola (No. 24) begin to move ahead.

 During a pit stop, Rudolf Caracciola holds up a tarpaulin in an attempt to shield himself from splashed gasoline as fuel is pumped into car No. 24 by a crew member stretched over the bodywork.

Victor Hermann Lang cruises into the pits at the race’s end.