Throwback Thursday – Porsche 911 SC 3.1: the pursuit of power
In the sports car world, it is a well-established convention that each successive model is more powerful and faster than its predecessor, and Porsche has consistently stuck to this rule – except for a brief period in the 1970s. The rise of US emission regulations caught out all the motor manufacturers, especially America’s muscle cars, which were completely hobbled.
However, thanks to its superior engineering, Porsche managed to avoid the worst of the power deficits: in 1976, the top-of-the-range Carrera 3.0 was only 13bhp down and had the same torque as the celebrated 2.7 of 1973-74. However, when the Carrera and the lower output K Series 2.7 made way in model year 1978 for the SC, there was considerable disappointment that the latest Porsche was rated at ‘only’ 180bhp.
There was also surprise that, for the first time since the launch of the 911S in 1966, there was only one atmospheric 911 model, plus, of course, the 3.3 Turbo. This simplification reflected the fact that Porsche was now also making the two transaxle models, the entry level 924 and the 928.
The latter in particular was the creature of Dr Ernst Fuhrmann who saw it as the successor to a 911 he felt was fast becoming obsolete, especially as it was apparent that Europe would copy American restrictions on exhaust emissions and also demand better mpg. Improving the 911’s credentials here was one reason for the reduction in power, and limiting the 911 to 180bhp was also intended to differentiate its performance from the 240hp 928.
In fact, after promising beginnings, the emotional tide within Porsche had swung against the 928 when it became apparent that the new model would limit the life of the 911. Indeed, the only advocates of the futuristic 928 seemed to be Dr Fuhrmann and Design chief Tony Lapine.
This rather isolated Fuhrmann and made him increasingly defensive about ‘his’ 928. In 1978 he issued a Verbot on any further development of the 911, which included the competition programme: the privately entered Alméras 911 that gave Porsche its fourth (and last) Monte Carlo victory the same year was officially ignored by Zuffenhausen; through the back door though, customer motorsport manager, Jürgen Barth had more than a hand in the triumph, and many at Porsche would discreetly raise a glass.
But in an atmosphere where even R&D director Helmuth Bott was threatened with consequences if he continued work on his 911 Speedster project, there was little encouragement for 911 enthusiasts who might have hoped for a 911S version.
Nevertheless, pressure built up both in and outside Porsche to offer some sort of powerkit, if only to counter offers from Reutlingen Porsche dealer, Max Moritz, and the irrepressible Alois Ruf. Both tuners had bored out the 3-litre from 95mm to 98mm, and with other modifications were getting well over 200hp. Porsche already had the advantage of a 97mm bore in house, which was used for the 3.3 Turbo, so coupling these cylinders with the stock 3-litre’s stroke of 70.4mm would result in a capacity of 3,122cc.
To read more about the rare, powerkit 911 SC 3.1, download Total 911 issue 143 to your digital device now.