Last night I finished installation of pressure indication on the E61 group head to compliment my existing Eric's Thermometer and Bianca profiling valve.
I did some additional water flow measurement and I can only get 5ml/s flow with the valve fully open but able to fully close in the LH position. I will likely do an orifice modification to improve the flow rate a bit in the RH position.
I created a video to show folks the mods and posted it to Youtube (first one ever). Sorry the video is a little fuzzy. Amateur.....
The first Youtube link apparently didn't work. Try this one. http://www.youtube.com/watch?v=3kuUbLOGpeQ