This paper describes further development and testing of the Renormalization and Nonuniform Coarsening (RNC) scale up algorithm, which was recently introduced in Ref. 13. RNC scale up combines nonuniform coarsening with upscaling of the absolute and relative permeabilities to provide coarsened descriptions of two-phase immiscible flow. We diagnose a known bias in the two-phase upscaling algorithm used in RNC. An unbiased alternative is introduced and incorporated into RNC scale up. The modified RNC scale up algorithm is tested on displacements through two dimensional cross sections with permeability and porosity data from conditioned reservoir simulations, and three dimensional linear and quarter-five-spot pattern displacements through computer generated permeability fields. Each reservoir description, measured or synthetic, contains highly heterogeneous and highly layered permeability fields. RNC scale up is used to coarsen these reservoir descriptions by a factor of 300 to 1000. The coarse grid oil cut curves show consistently close agreement with the fine grid curves in overall shape and in breakthrough time. The results are comparable to earlier results in Ref. 13 on displacements through synthetic two dimensional data.