Just an attempt to get back on topic - My memory of the quickest SOHC Honda drag bike on gas ran sub 8.5 second et's. Somebody with a better memory than mine can give the name. Was on my side of the Atlantic. As I recall, he had clutch/clutch basket problems with the horsepower he was making. No turbo, no nitrous, no blowers involved. Tranny's weren't best for the application. With the right ratio's and a power adder I'd expect that you'd be into the 7's without nitromethane. Build a nitro bike today - you'd use none of the original parts. Replica's of the appearance of the motor at best. Back in the day, no one knew the correct nitro fuel/air ratio like they do today. With so much fuel going into each cylinder, you got to pray that each cylinder fires every time. One fouled plug(s) and the cylinder head tries to depart from the rest of the motor. The Harley nitro bikes have learned that one too often. Ballistic jackets and many attempts to tie down the cylinder heads try to keep the riders alive when things go boom. Back in the day, the riders were above at least one of the motors. Now almost all 4 cylinder nitro bikes put the boom parts behind the majority of the rider. Harley nitro bikes are down to the 6.1's. The four cylinder nitro bikes have relatively stagnated with about a 5.8 second best. Can they make more horsepower? I'd say yes. How do you stop an over 250 mph motorcycle? Carbon/carbon brakes and a lot of faith. Parachutes have their own life threatening problems when slowing down a top fuel bike. With little purses and few races for the top fuel bikes, the innovations have slowed significantly. If you check the Dragbike.com forums, there is a team building a sequential dual turbo/alky bike that they think can run with today's nitro bikes. (Over 7 horsepower per cubic inch) Apply today's technology to a SOHC motor and you can probably go very, very quick while spending a major amount of money. I'd recommend a spare driver, just in case.....
Jon Weeks