Mercedes-Benz W194 300 SL

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After enjoying significant success as separate firms during motor racings early days, the merger of Mercedes and Benz in 1926 created an industrial behemoth.

Once Adolf Hitler’s Nazi party came to power in 1933 substantial government funds were diverted to both Mercedes-Benz and rival manufacturer Auto Union for Grand Prix racing from the 1934 season until the outbreak of World War II. The result was absolute domination of the sport: Germany’s nationalistic approach left conventionally funded Italian, French, British and American teams unable to compete on equal terms.

Six years after hostilities had ended Mercedes-Benz executives agreed on a return to top flight motor racing in June 1951. However, as the new 2-litre un-supercharged Formula 1 regulations didn’t reflect the firm’s technical aspirations, a Sports car built for the 1952 season was considered the most appropriate option.

Since 1947 Ferrari had established themselves as the dominant force in this class of racing but Mercedes’ big budget car would also be pitched against an exceptional field of new models from Jaguar, Aston Martin and Alfa Romeo plus specialist firms like Gordini, Cunningham and Allard.

Given type number W194, the new 300 SL (Sport Light) used many mechanical parts from the W186 300-series that had been introduced a few months earlier in April 1951.

A brand new tubular steel chassis weighing just 70kg was draped in a neat aluminium body, the distinctive Gullwing doors being required because of two large bulkheads that ran down each side for extra torsional rigidity: this resulted in very high door sills. The wheelbase was 2400mm and the front track narrower than the back (1381mm and 1445mm respectively).

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By canting the engine at 50° in the chassis, Mercedes was able to give the car a very low profile and exceptional aero efficiency. Front suspension was via coil springs and unequal length wishbones, the rear suspension components being lifted primarily from the W186 300 with swing axles and helical springs. Telescopic dampers were fitted all round along with finned hydraulic drum brakes and 5 x 15-inch Rudge wheels originally shod with Englebert and later Continental tyres.

Bodywork was designed and fabricated in-house at the Sindelfingen works with the exception of the first two prototype shells that were manufactured at Unterturkheim.

Of the ten W194s built, nine were originally completed with closed Gullwing bodywork and one as a Spyder. Three of these Gullwings were then transformed into Spyders mid-season.

Mercedes’ 2996cc Type M194 overhead camshaft Straight-6 engine was suitably modified from its origins in the W186 300-series, the canted 50° angle requiring spark plugs to be repositioned from the block to the cylinder head. Also featuring a high lift camshaft and a bank of three Solex downdraught carburettors, compression was upped from 6.4 to 8.0:1 and peak output rose to 175bhp at 5200rpm.

Early examples used wet sump lubrication to save weight but this was soon changed in favour of a racier dry sump arrangement.

Mercedes’ existing W186 four-speed gearbox was installed in the 300 SL but uprated with a separate oil pump.

A huge fuel tank was located behind the rear axle and the fuel level had a major impact on handling. Furthermore, the rear swing axle was joined only at the differential and not the wheels themselves which led to potentially extreme changes in camber on imperfect road surfaces.

Mercedes’ first prototype was running by November 1951 and four months later in March 1952 the finished article was shown to the press. Although performance figures were never published, the 1130kg Gullwing was estimated to have a top speed of around 155mph.

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The new cars made their competition debut on May 4th 1952 when a trio of silver Gullwings were entered for the Mille Miglia to be piloted by Hermann Lang / Erwin Grupp (chassis 003), Karl Kling / Hans Klenk (004) and Rudolf Caracciola / Paul Kurrle (005).

Chief opposition came from Scuderia Ferrari who were backed by a legion of privateers most notably the Scuderia Marzotto operation running a five-car prancing horse team. Jaguar and Aston Martin had both brought cars over from England although the latter would be contesting the GT class with its DB2s.

Following more than twelve hours of hard road racing around Italy, Ferrari’s experimental 250 Sport Berlinetta driven by Giovanni Bracco and navigated by Alfonso Rolfo emerged victorious but only after the second place Kling / Klenk Mercedes had been forced to make a late stop for a loose wheel. Luigi Faglioli and Vincenzo Borghi were third in a Lancia Aurelia B20, the Caracciola / Kurrle SL finishing fourth while the unfortunate Lang / Grupp entry crashed out.

Two weeks later, the Swiss Formula 1 Grand Prix at Bern hosted the Prix de Bremgarten for Sports cars: four Gullwings were entered for the 18-lap race. Three were the cars used on the Mille Miglia, these having been repainted powder blue (003 Lang), green (004 Kling) and dark red (005 Caracciola). A new silver Gullwing (006) was also entered for Fritz Riess.

Fastest in qualifying was the works Ferrari 340 America of Willie Daetwyler followed by the SLs of Ling, Caracciola and Lang. The factory Aston DB2s and Lancia Aurelias were next, Fritz Reiss starting 11th after switching from 006 to the spare car for the race.

Once the pole-starting Ferrari had retired, Mercedes were able to take a dominant 1-2-3 finish - Kling, Lang and Riess finishing in that order. However, the race was marred by a career ending crash that left Rudolf Caracciola severely injured, his SL locking its brakes and skidding into a tree.

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Three new Gullwings were subsequently built up for the 1952 Le Mans 24 Hour race that was to be held over June 14th and 15th all of which were painted silver and featured newly extended doors. Chassis 007 would be driven by Lang / Riess (blue noseband) and 008 by Kling / Klenk (green noseband). In the absence of Caracciola and Luigi Faglioli (both injured) chassis 009 was entered for Theo Helfrich and Helmut Niedermayr (red noseband).

Qualifying saw the Luigi Chinetti-entered Ferrari 340 America of Andre Simon and Lucien Vincent go quickest followed by the Jaguar C-Type of Stirling Moss and its owner Peter Walker. In third was the brutish Chrysler-powered Cunningham C4-RK of Phil Waters and Duane Carter, fourth the Gordini T15S of Jean Behra and Robert Manzon, a works C-Type driven by Tony Rolt and Duncan Hamilton starting fifth. The SLs were ninth (Helfrich / Niedermayr), tenth (Land / Riess) and eleventh (Kling / Klenk).

During practice the team had been experimenting with a roof-mounted air brake but this was abandoned on safety grounds.

A very high attrition rate in the race saw most of the favourites retire leaving Lang / Riess and Helfrich / Niedermayr to come home first and second respectively. However, it had been a somewhat fortuitous victory for the German squad who inherited the lead in the final hour when the Talbot-Lago T26 GS Spider that had been driven single-handedly by Pierre Levegh lunched its engine while leading by over 20 minutes.

Rounding out the podium was the special-bodied works Nash-Healey of Leslie Johnson and Tommy Wisdom that finished 15 laps down. The third SL driven by Kling / Klenk went out in the ninth hour with electrical problems.

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Another Formula 1 support race was held for Sports cars at the 1952 German Grand Prix on August 3rd, Mercedes sending a team of 300 SLs for this important domestic event. Four works 300 SL Spyders were delivered to the Nurburgring: one was a new chassis (010), the three other cars having all been re-bodied from Gullwings (006, 007 and 009). Chassis 010 was a brand new Spyder built on a shorter 2200mm wheelbase chassis.

Also present during practice was Gullwing chassis 004 which was trialled with a supercharged engine, the Rootes blower producing 230bhp. It was not used in the race.

Opposition to the Silver Arrows was limited and the grid lined up with Kling on pole in the short wheelbase car, Lang second, Robert Manzon’s works Gordini T15S third, Riess fourth and Helfrich fifth.

Once Manzon had retired the Gordini with a broken gear lever the race turned into a Mercedes benefit. Lang took the win in 007 (blue wing flashes), Kling was second in the short wheelbase 010 (black flashes), Riess was third in 009 (red flashes) and Helfrich fourth in 006 (green flashes).

After a glittering season of success the 300 SLs were wheeled out for one final event, the 1952 Carrera Panamericana road race. Opened up to Sports cars for the first time (as opposed to simply production models), in terms of prize money the Carrera was the most lucrative event on the calendar.

Three silver cars would contest the near 2000 mile race starting November 23rd - Gullwing 005 for Lang / Grupp (blue flashes), Gullwing 008 for Kling / Klenk (green flashes) and Spyder chassis 009 for Fitch / Geiger (plain silver). All were sponsored by Mexican Mercedes-Benz agent Prat Motors SA and ran bored out 3.1-litre engines.

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Ferrari sent a trio of new 340 Mexicos, these cars having been developed specially for this event with further uprated 280bhp engines and narrower track to increase their top speed along the straights. Also present as part of the works Ferrari squad was the Mille Miglia-winning 250 Sport along with a two-car team from Gordini who took along a pair of their venerable T15S.

An eventful campaign saw both Gordinis and three of the Ferraris fail to finish whilst the Fitch / Geiger Mercedes was disqualified on the final stage for receiving outside assistance.

This left the Kling / Klenk Gullwing to finish over 40 minutes ahead of the Chinetti / Lucas 4.1-litre Ferrari 340 Mexico in third, Lang / Grupp’s second place making it another dominant showing by the German squad.

Thereafter although tentative plans were made for a 1953 programme, the W194s were retired from competition as Mercedes focused on the W196 F1 development programme.

After the green light was given for a production version of the 300 SL in early 1953, an eleventh W194 Gullwing was manufactured and used for development purposes (chassis 011).

Text copyright: Supercar Nostalgia
Photo copyright: Mercedes-Benz -