You do not need a new engine to travel to the anomaly. Just bring your engine to 50%.
You need to fill the second and third "path" in the engine configuration screen for that (Theres two more rows with empty slots = the black boxes). Just put in some output modules and tunnelling modules and positron devices...
below is an image of a 100% system. You dont need any ai cores at this point.though to get to 50.
Once your got to the anomaly things develop... :)