These are 140 mm.

I have 4 fans, 2 on each side of the vertical blade.

So iam cooling my power and hashing module from both sides with
the powerful scythe ultra kaze 120 mm 3000 rpm and 230 m^3/h.
Each fan needs around 7 watt.
My heatsink is on 28 C, my chips are on 46 C and my powermodule on 26 C.
Overclocked at 1.2 V, running at 13200 mhs.

I took the temps after 30 hours and choosed the hottest spots of each modul.

Dont know, what are the max temps?
I think with this temps the blade will live forever

Please dont use the same cables to connect blade and fans or for two blades...cables could get hot and ... melt

Really not worth to risk and try. Only a advice.