Abstract: An engine for a vehicle. The engine includes a cast engine block having a hybrid insert disposed in a fastener bore having rolled internal threads. The hybrid insert includes an internal surface having cut inner diameter (ID) threads and an external surface having rolled outer diameter (OD) threads. The rolled OD threads of the hybrid insert are received in the rolled internal threads of the fastener bore. The hybrid threaded insert may include a bi-metal in which the ID threads are formed of one metal alloy and the OD threads are formed of another metal alloy. Alternatively, the external surface of the hybrid insert may define locking features and the engine block is cast onto these locking features, thereby locking the hybrid insert to the engine block.