thoroughly re-engineered by Koenigsegg themselves and is assembled at the Koenigsegg factory . [11] [12] The engine block for the dual overhead camshaft , 4 valve per cylinder 4.7 liter 288 cu in (4,719 cc) V8 [1] [8] [13] is cast for them by Grainger & Worrall, a British company that produces drivetrain components