Formula 3 Opel

With Opel, Spiess entered the days of the 4-valve engines. Spiess was supplied with the engines by Opel for testing and optimising purposes. Just three months later, the work proved to be successful, with the test-bench tests demonstrating a clearly improved performance. The advantages of a 4-valve engine compared to the conventional 2-valve engines were obvious. Furthermore, the Opel engine was the first Formula 3 engine ever to be equipped with a knock control, by Spiess. This control was adjusted in cooperation with Opel and Bosch and prevented extremely expensive engine blow-ups. After all, a fuel of identical quality wasn't available at all the circuits all around the planet, in those days. Another important step to success was achieved by Spiess by the mounting of a variable induction pipe with variable inlet camshaft - this way, both torque and power could be increased. The Opel Formula 3 engine has continued its triumphant success until today. It represented the most complex Spiess design so far.