cyclerider57

It's shape... not size. Yes, I use epox when needed. The "high velocity porting" is a myth of the port world. Making a port smaller does not increase performance unless the port started to large OR unless it is filled in very specific areas where flow is dead. Part of the reason this "motoman" increased performance by filling in the port on the street bike was because it improved the shape dramatically. He easily could be entirely too small for that engine BUT too small is better than too big as well as the fact that the filling in created a flat short turn radius. This evens out the pressure distribution through the ports turn because the lower moving flow along the short turn creates a higher pressure area that tries to separate from the port wall to early and wants to join the high velocity, low pressure flow along the ports long side flow.

__________________
The wise understand by themselves; fools follow the reports of others. Goodness speaks in a whisper, evil shouts. -Tibetan Proverb