Sooooo, the “open” part of the open chamber...... the part of the chamber on the other side than the spark plug....... that’s the part that’s shrouding the valves?
Admittedly I haven’t had a W2 head here in the shop in quite some time, but I don’t recall the original w2 chamber being any different than a std X or J head.
No, the side on the spark plug side. There is a curvature to the chamber which is very gradual on some designs. The 360-2 is a more abrupt curvature, that to a degree, shrouds the intake valve.
