Originally Posted by
German Muscle
Cutting the crankshaft counterweight like that will induce several negative effects.
-Promoting of turbulence
-Unbalancing the rotating assembly
-Increase in crank case volume
-Interruption of airflow
There is a well known modifier making these kinds of mods:
http://www.powerhousercperformance.com/
And he has explained several times on this forum the why of this mod, personally I think it is more a signature.