depth is approximately 0.8d through 1.2d where d is diameter of hole.(VDFC)
note how sharp the corners of each pin are....... that, combined with the concave sides of the pin equals MEGA Turbulence. I've seen some close ones, but most has a short straight channel, as it where, between the holes. A result of not having the holes virtually touching each other....
the perfect concave square pin shape is what we want with this design.
I feel I have to warn though.... it is not easy drilling so many holes so straight and so close to one another, the chances of screwing up is..... well lets say it's not the same as you winning the lottery....
... nuf-Said Some more pictures....
