working on calculating my exhaust system diameter. I have very limited room to work with on a single exhaust pipe. doing the math puts the intake cfm at 117cfm@10k rpm without any restrictions. obviously with filters, carbs and valves in the way the baseline of 117 would be high. but a seemingly good place to start. I see the valves being the main restrictions. hence my question. has anyone bench flowed a stock cylinder head? if so what did ya get? also what exhaust temps would I expect? being its an air cooled I can assume quite high at times. also I calculated the 117cfm from this 40ci x 10000 rpm = 400,000 / 2 then divided by 1720. so that all sound about right? thanks folks!
