Quote:

A lot of this was really testing the primaries. The secondaries on the 390 opened about 1/2 way, on the 450 a little bit, on the 500 a little bit, and on the 600s hardly at all tho the secondary transition circuits did help.

So, you can say that all those 4 barrel carbs were too large for the tested engine? Maybe a 300 cfm 2 barrel ?


70 Triumph 650 cc ECTA current record holder