Unlike a standard atx case, the Lian Li PC-V351 is a cube that measures 279mm x 262mm x 373mm.
The case is designed for a micro-atx motherboard mounted in the bottom and drive bays and a power supply above the motherboard. As a result space for a cpu heatsink is limited. The height of a cpu heatsink is limited by the compact case. I know for certain a 120mm tall heatsink will not fit. It will have to be a low profile heatsink.
You're in luck! The Blue Orb II has a diameter of 122mm and a height of 66mm. It will definitely fit inside the case.