Guide: Porsche 917 / 71 L
Background
At the 1970 Le Mans, had it not been for some rain-soaked electrics, one of Porsche’s long tailed 917s may well have won.
Further refinements were made in anticipation of a return to la Sarthe in 1971.
Porsche’s 917 Langheck was designed solely to win at Le Mans and would have been pretty uncompetitive at any other circuit on the World Championship calendar.
However, with its exceedingly long straights, Le Mans was an exceptional challenge and Porsche were prepared to forego precision handling in favour of monster top speed.
Bodywork
The subtly reworked 1971 Langheck body was a collaboration between Porsche’s Norbert Singer and the SERA R&D organisation in Paris headed by pioneering aerodynamicist, Charles Deutsch.
Once again, the 917 L nose was devoid of spoilers. Air was ducted through the front radiator and out through vents below the windscreen.
For 1971, the leading edge of the nose was flattened much like the 917/20.
The headlight cowls were re-shaped and large banks of air vents were carved out from above the front wheels.
The cockpit remained the minimum width specified by the FIA.
The rear bodywork section was now devoid of the NACA engine cooling ducts and large brake cooling scoops used in 1970.
As before, the long smooth tail terminated in two vertical fins that formed the sideplates for a full width rear spoiler.
The rear wheels were now enclosed above hub level with an arced cooling slat cut from in front of each tyre’s leading edge.
Overall, the body was 48mm wider and 45mm shorter than in 1970.
Chassis
Underneath, the same lightweight tubular alloy spaceframe was employed. As usual this was permanently gas-pressurised to detect any cracks.
Double wishbone suspension incorporated titanium coil springs with adjustable Bilstein-de-Carbon shocks and magnesium uprights.
Girling ventilated disc brakes and calipers were fitted.
The centre-lock wheels were mounted on titanium hubs. The same 15 x 10.5-inch magnesium alloy rims were used at the front with wider 17-inch rims installed at the back (up from 15-inches).
Firestone tyres would be used in 1971.
Engine & Gearbox
Although Porsche had a five-litre Type 912/11 version of Hans Mezger’s air-cooled 180° Flat 12 developed in time for Le Mans, all three Long Tails ran the proven 4907cc Type 912/10 unit coupled to a five-speed gearbox.
With a bore and stroke of 86mm and 70.4mm respectively, the Type 912/10 motor brimmed with advanced alloys. It employed mechanical Bosch fuel-injection with two separate ignition distributors to feed the 24 spark plugs.
Compression was 10.5:1 and peak output was 570bhp at 8100rpm.
Production
Of the original four Long Tails built in 1970, the first pair (040 and 041) were destroyed in massive testing accidents.
The remaining two (042 and 043) had been used at Le Mans and returned to the factory after the race. Both were re-bodied to the latest configuration and one new chassis was also built up for 1971 (045).
1971 Le Mans Test
Chassis 043 was selected to run at the annual Le Mans test weekend over April 17th and 18th where it was joined by three other factory-supported 917s.
This trio comprised a standard Gulf-liveried 917 K brought along by John Wyer Automotive Engineering (JWAE), a brand new plain white Kurzheck built on a special magnesium chassis, and the revamped 917/20 that would later become known as the ‘Pink Pig’.
Jackie Oliver drove the new long tailed car (also painted plain white) and went close to five seconds quicker then the new magnesium chassis 917 K that he shared with Jo Siffert and Derek Bell. This car was in turn one second faster than the standard 917 K that JWAE had brought along for direct comparison by same three drivers.
Fourth fastest time and just one tenth of a second behind the Gulf-liveried Porsche was the Ferrari 512 M of Escuderia Montjuich.
The 917/20 driven by Willi Kauhsen and Jo Siffert was fifth.
The re-bodied 917 L had proven even faster in a straight line than the previous year; it went through the speed trap along the Mulsanne Straight at over 240mph (compared to 227mph in 1970).
Under the extremes of cornering and braking, it still lacked the exactness of the Kurzheck, but was a massive improvement on the earlier streamliners.
A three hour race was also held during the test weekend in an attempt to increase attendance.
Derek Bell was down to drive chassis 043 and set a time quick enough for pole by a clear 7.5 seconds. However, the car was withdrawn before the start which left the 917/20 of Kauhsen / van Lennep as the only 917 representative.
After lapping the entire field within ten minutes, the 917/20 retired at mid distance when the engine cut out at Arnage and refused to re-start.
Over the next two months, further private testing took place with the 917 Ls in preparation for the Le Mans 24 Hours on June 12th and 13th.
1971 Le Mans 24 Hours
Three Long Tails to la Sarthe for the big race, two of which were painted Gulf colours for JWAE. The third appeared in silver Martini livery. All three were factory prepared and stuck with the proven 4.9-litre engines and five-speed gearboxes.
In support were a pair of 917 Ks (one for JWAE and a mag chassis example for Martini). Also present was the works 917/20 that ran under a Martini entry but was painted a wild pink colour scheme inspired by a butchers pig diagram.
The JWAE 917 L of Pedro Rodriguez and Jackie Oliver qualified on pole. It went one second faster than the Martini example driven by Vic Elford and Gerard Larrousse. Next up, a further three seconds back, was the JWAE sister Langheck of Jo Siffert and Derek Bell.
In fourth was the beautifully prepared Penske Ferrari 512 M of Mark Donohue and David Hobbs with Helmut Marko and Gijs van Lennep fifth in the mag chassis Martini Kurzheck. The ‘Pink Pig’ of Willi Kauhsen and Reinhold Joest started seventh while the standard JWAE 917 K of Richard Attwood and Herbert Muller was back in eleventh.
1971 was the first year of a rolling start at Le Mans and the three 917 Ls got off to a flyer. Together they proved they were easily the fastest cars in the race.
However, all three were forced into retirement after experiencing various engine and suspension troubles.
In the ninth hour, the engine cooling fan on the Elford / Larrousse Martini entry became detached which led to its Flat 12 motor overheating.
The same problem nearly afflicted the 917/20, but the problem was caught in time and the pink car continued until the twelfth hour when it crashed at Arnage.
Two hours later, the JWAE 917 L driven by Rodriguez / Oliver was also out. An oil pipe broke while Rodriguez was travelling at full speed down the back straight which showered the cockpit with scolding oil. The Mexican managed to limp back to the pits but by this time the engine had been terminally damaged.
This left just the JWAE sister car of Siffert / Bell which had experienced lengthy delays for rear quarter rebuilds due to broken shock absorbers. The same problem had also affected the Rodriguez / Oliver entry – it seemed the aero efficiency of the new bodywork was putting unexpected strain on the rear suspension.
Despite soldiering on, Siffert / Bell were out for good after sunrise on Sunday morning. A cracked crankcase forced their retirement in the 18th hour.
Only two 917 Ks remained and both ran the distance.
The white mag chassis Martini entry of van Lennep / Marko took victory by two laps from Attwood / Muller in the conventional JWAE machine.
Porsche had secured their second consecutive outright win at Le Mans.
Post Le Mans
After the race, the Martini long tail (042) was retained by the factory and later went on display at the Porsche Museum.
The new JWAE example (045), was gifted to the Le Mans Museum and re-painted Martini colours.
Chassis 043 (which had finished second in the 1970 race) was returned to the factory, put back to the 1970 body style and re-numbered 044. It was sold as a new car to Vasek Polak in 1975 who placed it on display at his Hermosa Beach Porsche dealership in California. Its true identity was later discovered, corrected by Porsche and the car now resides at the Simeone Foundation Automotive Museum in Philadelphia.
Text copyright: Supercar Nostalgia
Photo copyright: Porsche - https://www.porsche.com
