The rings on most radials are tapered. That is, they have an angle to the side surface that runs along the cylinder wall.
The angle is supposed to taper from touching at the bottom edge of the ring (in the top cylinder) to not quite touching at the top edge of the ring (in the top cylinder). That way, when combustion happens, the oil is wiped back into the crankcase. If the rings are tapered backwards (installed upside down, I've seen that a LOT of times!), the eninge fairly eats oil and the whole airframe is wet. If YOUR radial uses a LOT of oil, check the tapered rings! Some are backwwards, most likely. That happens when mechaincs don't even realize the rings are tapered. All the compression rings sould be tapered so the smaller diameter is toward the top of the cylinder.