Can this be turns on its side in the Storm D 4u server?

I'm not familiar with the D 4u Server. If you can insert two full size DVD/BD drives in your opening, you should be OK. I'm using two of these in a Dell T7500 Workstation where 4 full size DVD drives would be located. Tight Squeeze for the drives and the cooling may need some help... There is only 1.5 to 2mm space between 3.5" drives!