World's Fastest Indian

Boy..I'd love to look inside that engine. It's amazing that this old Kiwi guy still holds world speed records after 40 years on a motorcycle from the 1920s. Valves had rockers outside the engine. So what did this guy know that no-one can improve on today? You would think a modified Yamaha R1 could do it? Does anyone know any information on the engine in the record breaking motorcycle? I know it was 1000cc and running on Methanol. This website says that the barrel was made from an old cast iron water pipe with aluminum fins. Quote: In their final form he in effect hand-carved his con-rods from a Caterpillar tractor axle, and hardened and tempered them to 143 tons tensile strength. Burt Munro