General Electric YJ93 / 7E

 
YJ93-GE-3

The General Electric YJ93 turbojet engine was designed as the powerplant for both the North American XB-70 Valkyrie bomber and the North American XF-108 Rapier interceptor. The YJ93 was a single-shaft axial-flow turbojet with a variable-stator compressor and a fully variable convergent/divergent exhaust nozzle. The maximum sea-level thrust was 28,800 lbf (128 kN).

The YJ93 started as the General Electric X275, an enlarged version of the J79 turbojet. This evolved to the X279 when Mach 3 cruise became a requirement, and ultimately became the YJ93.
 
The engine used a special high-temperature JP-6 fuel. The six YJ93 engines in the XB-70 Valkyrie were capable of producing a thrust to weight ratio of 5, allowing for a speed of 2,000 mph (3,200 km/h) (approximately Mach 3) at an altitude of 70,000 feet (21,000 m).
 
The XF-108 interceptor was cancelled outright and the B-70 project was reoriented to a research project only.
 
GE4/J5P
Type: Turbojet
Length: 6.2 m (237 in)
Diameter: 1.33 m (52.5 in)
Dry weight:
Compressor: 11-stage axial
Turbine: Two-stage axial
Fuel type: Special high-temperature JP-6 Fuel
Maximum thrust: 19,000 lbf (85 kN) / (28,800 lbf (128 kN) with afterburner)
Specific fuel consumption: 0.700 lb/(h·lbf) or 19.8 g/(s·kN) / (1.800 lb/(h·lbf) or 51.0 g/(s·kN) with afterburner)