Trailblazer Returns – the Porsche 917-001 Le Mans winner
21 April 1969 is the date to remember as the first Porsche 917-001 received a homologation certification from the official motorsport bodies back then. It was thereby approved for racing. This car, even though purpose-built for racing, didn’t compete in races. It was instead used as a test and presentation vehicle. With German F1 driver Rolf Stommelen behind the wheel, the Porsche 917 completed test drives on the Nürburgring’s South Loop on 14 May 1969, before taking an endurance run on the Weissach skid pad a little later, to test the wheel bearing.
It was also exhibited in September 1969 at the German International Motor Show (IAA) in Frankfurt. This vehicle sported orange and a white paint scheme with the green front for the show. Soon enough, on 30 September 1969, Porsche announced that it will no longer use its own works race team and will instead partner with J.W. Automotive Engineering, the race team of two-time Le Mans winner John Wyer. It gets displayed various motor shows and parades till 1970 sporting varied paint jobs.
The Porsche 917-001 is transformed into a Le Mans winner
However, the wait is worth it as the Porsche 917-001 wins its first Le Mans in September 1970. This was a short-tail version driven by Hans Herrmann and Richard Attwood. The alterations included a modified rear frame, a new front and rear body and a modified exhaust system that extends the exhaust pipes from the front six cylinders of the V12 engine towards the back instead of the side. The same car was later sent for display at the Paris Motor Show. The car eventually becomes a permanent feature of the museum’s collection.
Restoration of the 917-001 to its original condition
In preparation for the forthcoming “50 years of the 917” anniversary event, the Porsche Museum decides in 2017 to restore the 917-001 to its original appearance as on the first outing in Geneva in 1969.
The first technical assessment was conducted in January 2018. A great deal of work was required to restore the Porsche 917-001, though the fundamentals are encouraging: although the conversion to a short-tail version involved shortening the rear, the car was still equipped with its original aluminium frame. The modifications required the construction of a new rear frame. Also, a body with a detachable long-tail section made from fibreglass polyester laminate was manufactured. The rear-axle kinematic lever system for both rear air flaps also requires restoration for use as in 1969. The roof section with windscreen, window frames, doors and door frames was still in its original condition so it did not need to be changed.
Experts from the Porsche Museum completely dismantle the 917-001 in February 2018. During disassembly, another clue was uncovered that proves just how authentic the 917-001 is: on the right sill, you can clearly see that the original recess for the 1969 exhaust system was later sealed with fibreglass laminate.
Extensive restoration of the body using state-of-the-art 3D technology
As far as possible, original materials and parts must be preserved when restoring the Porsche 917-001 to its original condition as in 1969. That’s why the car’s assembled body frame was scanned using 3D technology. New CAD data was calculated by reverse engineering this scanned data (surface reconstruction), which is created from the original drawings, and eventually helps cut the negative moulds to construct the new body parts with absolute precision. Because only a single piece of any body part is required at a time, the negative moulds were machined directly out of the material Ureol, saving valuable time and money. The new body parts are ultimately created from a similar polyester laminate to ensure that they are as authentic as possible.
Manufacturing air flaps and their mounts in accordance with original drawings
In the weeks that follow, the rear hood, attachable long-tail section (the “backpack”) and front and rear air flaps are manufactured. The original construction drawings from the Porsche Museum’s archive can be used as a reference for almost all of the parts that need to be reproduced, and this is no exception. The rear air flaps have a particularly intricate design, as is evident from their close similarities to aircraft construction: they require two parts, moulded from fibreglass-reinforced plastic, to make up the outer skin of the flap’s upper and lower surface. In the front section, an aluminium tube acts as a shaft to which two stiffening ribs and a sheet of aluminium are welded, much like an aircraft wing. At the rear, these flaps continue the kinematic element for linkage with the rear axle’s wheel knuckles, while the front remains static. This latter part is being recreated because the 917-001 featured exactly this configuration when it was exhibited at the 1969 Geneva Motor Show. Hans Mezger, Chief Engineer of the 917, is also consulted about this feature, and his conclusion could not be more positive: “It makes me very happy to see that this project is in such capable hands. I’m so impressed.”
Working against the clock – reminiscent of Geneva 1969
All of the body parts and the assembled frame are carefully sanded, smoothed out with filler and painted white in January 2019. Finally, the front of the vehicle is adorned with the green “Geneva nose”; the Porsche emblem is placed in the middle, over the air intake for the oil cooler; and the striking 917 logos is affixed in black, just as it was back then.
Only four weeks now remain to reassemble the Porsche 917-001 and restore it to roadworthy condition, complete with newly cast magnesium wheels as per the original design. Specialist mechanics are working to complete the restoration of the very first Porsche 917 on time, under almost the same time pressure as 50 years ago. Same as back in the days, the car needs to be finalized for its presentation. This time it is not Geneva, but the Retro Classics in Stuttgart.