Quote:
Originally Posted by cgeise
Bottom line is - If you can get the same cfm with a smaller oval port head as a square port head like a tiger -- you you have a faster head - more efficient
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not that simple!
http://speedtalk.com/forum/viewtopic...=26832#p309363
a comment from Curtis Boggs on assumption that Oval is a better port>
"I'd have to say right off the bat that the above statement is not correct.
Simple, the proper port shape is the one that gets the job done properly, .. period!
Oval ports don't just "flow better", .. port shape is primarily about reduction of turbulence in the port, ..
proper velocity profiles, and delivery to the back of the valve.
The shape that does that best in whatever head design you have to work within, is the "proper" port shape.
Studying fluid dynamics and flow through pipes etc can lead you in directions that my influence your thoughts here.
When you have to try an turn air ( or fluid ) or get it around bends and turns, .. or effect how or where the bulk of the flow is biased, .. it's done with variations in shape.
Simply saying one "shape" is the the "one" or the key to the kingdom is just limiting yourself
from any forward advancement past that point. There is no one magic shape.
I have square port shapes in heads and classes where you wouldn't expect with record setting performance."