Porsche 917K

The Porsche 917K — Kurzheck, short tail — was a revised aerodynamic configuration of the 917 developed between the 1969 and 1970 racing seasons. Where the original 917L long-tail had proven unstable at high speed, the truncated rear body of the K variant reduced lift and improved balance, at the cost of a modest reduction in terminal velocity on long straights.

Under the management of JW Automotive Engineering and the Porsche Salzburg team, the 917K claimed Porsche’s first outright victory at the 24 Hours of Le Mans in 1970 — driven by Hans Herrmann and Richard Attwood — and repeated the achievement in 1971 with Helmut Marko and Gijs van Lennep setting a distance record that stood for more than a decade.

The chassis used an aluminium spaceframe construction, progressively evolved through the production run from the original magnesium-heavy frame toward an all-aluminium structure following fatal incidents linked to magnesium fires. Power came from the Type 912 air-cooled flat-12 engine, displacing either 4.5 or 4.9 litres depending on configuration and season.