Measurements of the mean velocity, wall shear stresses, and turbulence have been performed in a rod bundle of four parallel rods arranged in a rectangular channel (P/D = W/D = 1.148) for three ratios of length-to-hydraulic diameter (L/Dh). Distributions of the mean velocity and the wall shear stresses have been measured in four quadrants for L/Dh = 48.7, 73.0, and 97.4. The full Reynolds stress tensor has been determined by the hot-wire technique in only one quadrant for each L/Dh ratio. The Reynolds number of this investigation was Re = 1.17 × 105. The experimental results show that the structure of turbulence does not change significantly between L/Dh = 48.7 and 97.4. The flow redistribution among the subchannels caused by the inlet conditions, however, is not completed at L/Dh = 97.4. The experimental wall shear stresses at L/Dh = 97.4 agree satisfactorily with the wall shear stresses calculated by the VELASCO code.