I want to remove a wall in old house that runs perpendicular to the ceiling joists. Single story house that was built in 1945. Pier and beam foundation.

The wall I want to remove is 15' wide x 10' tall and is currently full 2x4 (really 2x4) on 24" centers and each side of the wall is sheeted with 1x10s with virtually no gap between them. The wall is then covered with 1/2" drywall. It is built like a tank.

To remove this wall, how big of a beam do I have to have or can I 'sister' with bolts a 2x10 or 2x12 to each side of the existing wall (at the top of course) to act as a beam.