A method of constructing a bedplate assembly for retention of a crankshaft in an internal combustion engine having an engine block includes forming a bedplate insert in a first pattern tool. The bedplate insert is defined by a height, a width, and a thickness. The bedplate insert also includes a shape having a variation in the width along the height. The method also includes arranging the formed bedplate insert in a second pattern tool. The method additionally includes forming in the second pattern tool a bedplate frame around the formed bedplate insert to generate the bedplate assembly. During forming of the bedplate frame, the variation in the width of the bedplate insert generates an internal rib in the bedplate frame that is configured to fix and retain the bedplate insert inside the bedplate frame and decrease deflection of the bedplate frame under crankshaft loads during operation of the engine.