GE4

The General Electric GE4 turbojet engine was designed in the late 1960s as the powerplant for the Boeing 2707 supersonic transport. The GE4 was a nine-stage, single-shaft, axial-flow turbojet based largely on the General Electric YJ93 which powered the North American XB-70 bomber. The GE4 was the most powerful engine of its era, producing 50,000 lbf (220 kN) dry, and 65,000 lbf (290 kN) with afterburner. The Boeing 2707 was cancelled in 1971, putting an end to further work on the GE4.