In the late 1950s, Porsche’s rear-engined 356 line was edging up on a decade in production, and the company had its eye on a successor to its venerable and beloved runabout. They didn’t want to go too large, as that was Mercedes-Benz territory; nor did they concern themselves with heading downmarket to compete with Opel or Volkswagen. The ultimate result of this soul searching is available today at your local Porsche dealer as something badged as a 911. It features a couple of vestigial back seats. Behind them resides a horizontally opposed six-cylinder engine. The basic silhouette of the car has remained the same since the 901 (quickly renamed to mollify an indignant Peugeot) appeared at the 1963 Frankfurt auto show.
Think of the T7 concept as the Cro-Magnon Porsche, a lineal break from the Neanderthal 356; it was a machine that largely presaged the company’s next 15 years of automobiles and continues to influence them in the present day. The T7 certainly resembled the 901 more than it did the 356. In fact, viewed head on, the concept could easily be mistaken for its production successor. Have a gander at the profile, however, and the differences are obvious. Rather than the harmonious, rounded fastback shape of the 901/911, the T7 looks as if a mid-Sixties anonymous German sedan had rear-ended a 901 and been assimilated, Borg style, into the automobile’s being. Not bad, considering that the full-scale mockup of the car was cobbled together in the waning days of 1959. Viewed in retrospect, designer Ferdinand Alexander “Butzi” Porsche’s Type 695 T7 design study was clearly puffing from the same pipe as Pininfarina. Both the T7 and the roughly contemporaneous Ferrari 400 Superamerica Aerodinamico feature wraparound rear glass that transforms a notchback shape into a fastback design, an idea that Mazda would later take to its logical extreme with the original RX-7’s all-glass rear hatch.
The 695’s powered successor, the Type 754, was originally fitted with the engine from a 356 Carrera 2. Known commonly as the Fuhrmann engine in honor of engineer Ernst Fuhrmann, who shepherded the powerplant into being, the four-cam engine was too noisy and too complex for the customers Porsche had in mind for its new automobile. It was, after all, at heart a racing motor. It did, however, make the 130 (DIN) horsepower the company felt was necessary for such a machine.
Having put serious development energy into flat-eight racing engines, the company decided that a two-liter six-cylinder engine would offer the smoothness and power output it desired for a roadgoing automobile while offering headroom for expansion. The company’s first attempt at a boxer six, the Type 745, was a twin-cam overhead-valve engine. In 1962, Porsche installed the new engine in the T7 for testing. Dyno results weren’t as promising as the company had hoped; the new engine made only 120 horsepower. When it was punched out to 2.2 liters, the desired output was reached, but the long, flexible pushrods meant that competition-grade power was out of the OHV six’s reach. After driving the 745-powered T7, Ferry Porsche reportedly banned further development of new pushrod engines.
The task of coming up with a new, overhead-cam take on the flat-six fell to Hans Mezger’s team. Mezger had worked under Fuhrmann straight out of school, and he went on to leave his fingerprints on Porsche engines all the way up to the vaunted 997 GT3 RS 4.0. After the company briefly experimented with a wet-sump, seven-bearing iteration of the OHC six known as the Type 821 engine, the group added an eighth main bearing to the design to ensure crankshaft stability. Meanwhile, the wet-sump version of what was now known as the 901 was still suffering from uneven oil distribution under extreme conditions. A young engineer named Ferdinand Piëch suggested that dry-sump lubrication was the way to go, and since he was a Porsche family member, his assertions carried extra weight. Piëch was also responsible for the use of triple-throat Weber carburetors, which weren’t prone to fuel starvation under high cornering loads like the Solex units his uncle Ferry preferred, although early 911s ultimately wound up using both brands of carburetors as well as Zenith units. So configured, the 901 powerplant arrived in 1963, and its fundamental architecture served in varying displacements until the arrival of full liquid cooling 34 years later.
While the motor was being developed, Erwin Komenda, largely responsible for the design of the 356, took a crack at a design for the new car. The company didn’t care much for his take on the new machine, although his T9 design, with large vents running the length of the decklid, attacked the T7’s major issue: its small side-mounted vents didn’t allow enough airflow through the engine compartment. By the time the 901 engine arrived, however, Butzi had moved on from the T7, refining its design into the T8, the prototype of what was to become Germany’s most recognizable sporting machine—the Porsche 911—an automobile that would find a home everywhere from the driveways of the reasonably affluent to the winner’s circle at Le Mans.
from Car and Driver BlogCar and Driver Blog http://ift.tt/2pHzUUC
via IFTTT
0 comments:
Post a Comment