5.7. 2.1 Engines with belt driven camshafts are permitted only in classes A , B , C , D , E , F , maximum 2 valves per cylinder .
Multi valve engine fitted as standard .
5.7. 2.1 Engines with belt driven camshafts are permitted only in classes A , B , C , D , E , F , maximum 2 valves per cylinder unless multi valve engine fitted as standard .