Passenger car production rose steadily during the

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1 commercial vehicles) in July 1947 the 1.7-litre 170V four-door sedan. Two new 170-series variants joined it in May 1949, and production continued until 1955, by which time the 180 had been introduced as a stablemate saw the revival of 6-cylinder engines with the launch of the 2.2-litre 220 series (W187) and the 3-litre 300 (W186 II) models in April that year. The sporting two-door 300S made its debut at the 1951 Paris Salon, and shortly after a deal was signed with Max Hoffman, securing a good sales outlet in America. Incidentally, Hoffman also handled Porsche imports for the United States. Many companies talk of pedigree. However, few can match the bloodlines behind the Mercedes-Benz brand The 300S Cabriolet A of 1952 vintage. Although an elegant machine, the styling was still very much influenced by pre-war design concepts. But changes were afoot, with the Ponton series leading the way...

2 Meanwhile, the announcement of two new sports cars at the 1954 International Motor Sports Show in New York had enthusiasts in raptures the 3-litre, fuel-injected 300SL, with styling inspired by the 1953 SL prototype, and the much simpler, smaller-engined 190SL. Although it would be some time before either SL made it into the showrooms (the second Type W SL, for instance, wasn t built until six weeks after the New York exhibition had ended, and even that was still a pre-production prototype), it was no coincidence that they were announced just as the latest W196 F1 car was about to hit the Grand Prix scene. 1952, 1953, 1954 and 1955 cars compared. The 300SLR at the far end can be seen in ultra-rare coupé guise (one of only two built)... Mercedes-Benz designations For many years, Mercedes-Benz models have been identified by a vehicle class letter (or series of letters) and a number, which usually relates to an engine size. It s a system that has continued to this day, with C 350 being a C-Class saloon with a 3.5-litre power-unit, although the engine displacements don t always tie-up precisely in the way they used to. The designation that interests us the most at this stage in the story, however, is 300SL. The 300 denotes a 3-litre powerplant, while SL is short for Sport and Licht in English, this would translate into a description of a lightweight sports (LWS) model. For reference, the addition of an R suffix (to make SLR) distinguished a pure racing model from the later production road cars, while a C (to make SLC) denotes a coupé version of the SL. One will also come across a K quite often in Mercedes circles, which used to refer to short chassis models pre-war (as in Kurz), but nowadays is taken to mean Kompressor, the German for supercharger. 28

3 5 Birth of the R107 After an eight-year production run, the Mercedes-Benz 230/250/280SL is being superseded by a new model, the longrumoured 350SL. It s a totally different car from the 280SL, from the tyres up, though it is styled to maintain an evolutionary resemblance to that successful series. Road & Track, June Passenger car production rose steadily during the 1950s, especially after the SL joined the Mercedes- Benz line-up. However, even in 1957, by which time the Gullwing 300SL had been joined by the infinitely more accessible 190SL, of the 81,000 cars produced by Daimler-Benz that year, only 3000 or so made it to the States. Ten years later, with annual production standing at 200,470 units, America was by now accounting for more than 10 per cent of worldwide sales. Within that figure, it was the SL that stood out as being particularly suited to the American lifestyle, as one in every two W113-series cars built was shipped across the Atlantic. It was therefore fairly obvious that the next generation SL given the R107 code would have to be designed in the knowledge that the USA was almost certainly going to be its number one market. The difficulty was always going to be striking a balance between bowing to American tastes and ever-tightening Federal regulations (which would have meant a huge gain in weight and changes to all four sides of the W113, had a decision been taken to modify the old SL rather than head in a new direction) and satisfying the marque s traditional customer base in the heart of Europe... The birth of the 107-series came at a time of change within the Daimler-Benz camp. While Rudy Uhlenhaut (left) was still head of the passenger car experimental department, Fritz Nallinger (right) retired as Technical Director at the end of 1965, leaving Hans Scherenberg (centre) to take over responsibility for all areas of product development as R&D boss. 50

4 was much cheaper due to the ease of fitting. A few other items, such as an electric sunroof (priced at DM 977), power windows (DM 438 for the front only, as per the SL, but DM 788 for all four), and a heated rear screen (DM 266), were naturally unique to the tin-top model. A passenger-side door mirror was also available (for DM 72), which was added to the SL option list in January Interestingly, the Europa stereo radio and Mexico radio/ cassette installations were DM 188 more expensive on the SLC. This was because of the two additional speakers fitted in the rear parcel shelf. The SLC was also available with a rear speaker fader as a separate DM 111 option. In January 1972, with C107 sales beginning in earnest, SL One of the first press pictures released for the four-seater 350SLC, finished in Sand Beige Metallic with a Mahogany cloth interior. The fashions of the time help date the shot. 74

5 The 3-litre M103 E30 engine in cutaway display guise. Starting with the 2962cc Type straight-six, this was quite different to the M110 unit, with a single camshaft, and an unrelated bore and stroke of 88.5mm x 80.2mm. A cast-iron block was retained for this engine, although there was a light alloy cross-flow cylinder head, playing host to the chain-driven overhead camshaft with hydraulic valve clearance compensation. With microprocessor-controlled electronic ignition (EZL), the latest electro-mechanical Bosch KE-Jetronic (CIS-E III) fuelinjection, and a 9.2:1 compression ratio, the engine delivered a healthy 188bhp DIN, or 180bhp when equipped with a threeway catalytic converter. The 5-speed manual gearbox was a Getrag GL76/27B-5 unit (Type ), with ratios of 3.86 on first, 2.18 on second, 1.38 on third, a direct fourth, and an overdriven 0.80 on fifth; the final-drive was listed at 3.46:1. Automatic transmission was via the W4A040 gearbox with its established internal ratios of 3.68, 2.41, 1.44 and 1.00, but the Type version was specified for the 6-cylinder model, combined with a 3.46:1 final-drive. Next up was the Type an all-alloy 4.2-litre V8. As noted earlier, this was related to the M116 E38 unit, with a 4mm bore increase taking the cubic capacity up to 4196cc. The bigger bore allowed larger valves, operated by the normal sohc per bank arrangement readily associated with Mercedes. With EZL, KE-Jetronic injection ( coupling mechanical reliability with electronic sophistication ) and a 9.0:1 compression ratio, it delivered 218bhp DIN at 5200rpm (203bhp with a cat), plus 238lbft of torque. Although listed from the start, full-scale production of this engine didn t actually begin until November It was linked to the 4-speed W4A040 automatic transmission, with its familiar cogs, but designated the Type when used with the Front and rear views of the 300SL, a designation that holds great meaning for fans of the Stuttgart marque. This was the third car to carry the name, officially capable of 124mph (198kph) and covering the 0-60 dash in 9.9 seconds in automatic form, although it was a fraction quicker with a manual gearbox. 173