For the 1969 racing season an absolutely new Porsche 917 with 4.5-litre 12-cylinder engine was created. Ferdinand Piëch relied on the skilfulness of Hans Mezger, who was responsible for the overall construction of the vehicle and its engine. The aim was to create the fastest racing car ever. Short and long tail versions were developed, called as the 917 K ("Kurz" = short in German) and the 917 LH ("Langheck" = long tail). The first car was assembled in December 1968.