Taking flight in a SSK

A chance to co-pilot one of Mercedes’ finest in the Mille Miglia Retro revealed some unexpected delights – and dangers…

Navigating the Mercedes-Benz SSK at dusk during the recent Mille Miglia Retro was quite an evocative experience. Folded into the great car’s confined cockpit with driver Michael Bock’s right elbow against my left as he juggled the vast wood-rim steering wheel, I was wearing a works-issued LED torch-headband so I could both read the 300-plus-page roadbook on my lap and hang on to the darned thing against the battering airstream as we pounded and bounded towards Bologna. Peering down my light beam like a novice proctologist I was bawling “240 metres fork left, signposted Argelato, six kims”. Thumbs up. Michael, a Morgan Plus-8 racer in his spare time from Mercedes-Benz Classic, rolled his foot onto the brake pedal and the copper-toned drums whistled their shrill song – comforting confirmation they were at least receiving the message.

You need that kind of confirmation in a ton-and-a-half of ’tween-wars battlecruiser, pounding through the Italian night at 80- 90mph on country roads with half-candlepower orange-hued headlamps your only other life insurance. And it was about then that we hit the raised ‘sleeping policeman’ of a pedestrian crossing on the outskirts of the town. The Mercedes SSK is said by some to be the nervous, flighty sister in the imposing S and SS series of great vintage sports cars. “It’s the short wheelbase of the SSK,” they’ll tell you. “It’s much more likely to step out and oversteer than the standard longer-wheelbase SS, don’t you know?” Hmm – well, from our experience, that’s not necessarily so. Perhaps it depends upon having some measure of throttle sensitivity, but in fact the SSK’s traction seemed pretty impressive and its rear tyres hardly ever broke adhesion despite what turned out to be some pretty heroic motoring on dry, damp and even snowy/icy roads on this particular Mille Miglia. Now, what became far more apparent to us was that the short-wheelbase SSK actually seems far more sensitive in pitch than yaw. The instant our front wheels and hefty beam axle struck that gloom-hidden ramp the front end launched skyward. Hardly had it touched down again when the rear wheels and back axle – just abaft my spine and kidneys (trust me) – rammed the same crossing ramp. Ooomph! And we reached for the night sky…

A lifetime interest in aviation as well as racing cars meant a name instantly flashed through my mind. Bernie Lynch, the Martin-Baker company’s intrepid fitter who became its ejection seat-testing guinea pig. Our ‘kaboom!’ moment was interesting for Michael his thighs crashed up against the underside of the SSK’s big steering wheel, smacking him straight back down into his seat. My experience was somewhat different. No steering wheel, no seat belt for the bearded baldy. So I landed with my backside against the folded hood behind the cockpit coaming, gasping in the direct airfl ow high above the windscreen. A grab for the bodywork, anything, my proctology beam wavering crazily around the dark sky, then – ker-plop – slither back down into my seat. “Phwoar, may I get back into the car now, Michael?”

Oh yes, upset the short-wheelbase SSK in pitch and, I would agree, in that plane it is quite nervous. In fact by the end of our second day in the car I felt quite comfy with the notion, as twice more we hit a really big bump or ripple, once at very high speed indeed on a stretch of autostrada, and – yet again – it was bum on back of cockpit time.

This made me think back to 1931 when Mercedes-Benz actually won the real Mille Miglia fi rst time round – with Rudolf Caracciola and Wilhelm Sebastian sharing the heavily drilled, much lightened SSKL. Caracciola and Christian Werner had shared the driving in their first Mille Miglia the previous year. Their SSK then finished sixth after 17hrs 20mins on the road. For 1931 Caracciola opted to drive the total distance with Sebastian as riding mechanic. That year the race ran anti-clockwise around the leg of Italy, the opposite way to that used when Moss and Jenks next won for Mercedes in 1955. But where 24 years later Moss in the 300SLR would average 97.9mph, in 1931 Caracciola still averaged 63.2. His race lasted 16hrs 10mins 10secs. Moss/Jenkinson’s occupied 10hrs 7mins 48secs. Now we were going to spend two-and-a-half days covering a broadly similar 1000 miles, though on open roads.

But thinking more on Caracciola/Sebastian’s feat – the first-ever Mille Miglia victory for non-Italians. Many miles of the thousand they covered in 1931 were loose surfaced, dust, grit and stones. Wash-outs and ripples would have been awaiting them round every turn. How many times must they have nearly been fi red from their seats à la Lynch? And me.

Caracciola’s SSKL, like ours, had a six-cylinder engine of 7.1 litres with supercharging selected by the driver. His SSKL (leicht = lightweight) developed around 300bhp. These big sixes have so much torque their acceleration impresses even without the blower engaged. The driver simply floors the throttle to wake it up. It’s like calling in your big brother in a bar-room fight. Floor the throttle and – with a keening wail like a bandsaw cutting concrete (as my friend David Burgess-Wise so memorably describes it) – your big brother supercharger kicks in. You have to be positive on the throttle to ensure positive engagement from the 45 steel discs comprising the supercharger’s clutch pack. Dithering on the throttle could burn out this clutch. The blower runs at 2.8-times engine speed, delivers up to 7lbs psi boost, and throttle flat, blower engaged, the rev counter climbs like a homesick angel. It’s not neck-cracking acceleration – more just effortless, relentless. And the limit is strict. Only engage the blower in 10 to 15-second bursts.

Mounted on the engine bay firewall there’s a five-litre fuel header tank like a lavatory cistern. Fuel is pumped into it from the tail tank, thence by gravity to the carburettor. But when the supercharger is engaged it blows into the carburettor, which would blow fuel back into this cistern. So a valve closes to pressurise it as well – and effectively it flushes. One result – in a well set up SS or SSK – is that relentless, unhesitating acceleration. Another, unless you lift within the time/fuel constraint, would be to wash the bores of lubricating oil. And a third is a massive blast of unburned hydrocarbon out of the drainpipe-sized exhaust. One driver of a modern BMW saloon emerged spluttering from such a banner cloud of fuel-laden smog to see the SSK he’d attempted to monster receding to a fine point. I think his poor car needed a respray. Oh, and the other thing I realised from 500 miles or so in Unterturkheim’s inter-war finest is just what a terrific contemporary hillclimb car the SSK must have been.

Caracciola was European Mountain champion in both 1930 and ’31 in his, and Hans Stuck Sr followed in his wheel tracks.

After our partial ejections I was still battered next morning when we found our scheduled flights home had been cancelled due to Icelandic ash. I grabbed the generous offer of a private flight out, including a first leg Brescia-Venice at zero feet – exciting stuff. As we aimed for the coast I was reminded of 617 Squadron’s home leg after their dambusting raid in 1943. As one of their Lancasters blundered across the heavily-defended railway marshalling yard at Hamm, the nose gunner complained to his skipper: “If we get any lower they won’t need guns. All they’ll have to do is change the points…” Coo-ee – what a weekend that was.