I thing maybe Karlos used the term Gas flowed in a more genric context. Karl did used to use flowbench's from when he worked at Jaguar to test different designs, but he then didn't use a bench to port individual heads - although this may have changed.

I agree about development if you do have a full on bench and fluid dynamics software, but for a tuner that isn't viable in the majority of cases.

Just look at the cncheads website, it says the Zetec head flows more than a YB head as std, yet we know in practise which engine will put out significantly more power on it's std head. It just isn't viable for non oem's to simulate pressurised turbulent flow.

Rick.