One that really stands out for me was the incredible H-16 engine that BRM built for the new 3.0 litre Formula One engine rules introduced in 1966. It was effectively two flat-eights stacked one on top of the other with their two crankshafts geared together. This jigger featured twin overhead camshafts per bank of four cylinders, so eight camshafts in all. Plus four valves per cylinder, meaning 64 valves in total. It was not only incredibly complex but also very heavy as you would imagine. Amazingly, the brilliant Jim Clark did win one F1 grand prix with this monster in the back of a Lotus while Colin Chapman was filling in time waiting for the new Cosworth DFV to become available. The H-16 was not a runaway success but you have to give BRM an 'A' for effort.