Gave up on the Beehive springs, they are possible but difficult and not as much gain as hoped.
Got my tricky Ford 7mm stem valves, guides, and Ford springs from Salv Sacco today.
Going to be a bit of work to install them but I am sure they will be worth it.
Nor certain how spring weight figures into valve-train calculations, but these weigh 48 g instead of 91 g.
Even if only half the weight is calculated as mass the savings are still significant.
Spring retainers in steel 14 g vs 32 g.
Aluminum would be 6 g, Titanium are 9.07 g and about $175.00.
7mm Intake 68 g vs 80 g.
7mm Exhaust 57 g vs 78 g
So I save at least 30 g - 39 g per valve not including the springs.
The Mini site claims each 10 g savings is good for an additional 350-400 RPM of revs.
I know my RPM is dictated by how long I want my crank to live, so no increase in RPM but hopefully significantly longer cam and valve-train life.
Thinking this should also be posted to the Paddock.