The Lotus 23 was not only beautiful, it was extremely fast and versatile. In its first international outing, Jim Clark led all the big bore cars at the Nurburgring until he had to retire. The 23 was built to take the 1.6 liter Ford 105E pushrod engine. It was even faster with the twin cam version of the same engine. George Follmer stuck a 4 cam Porsche engine in a 23 and won the first United States Road Racing Championship.