Comparison of Turbofans

Engine J79-GE-8 J79-GE-10/17 J79-GE-15
Physical Dimensions
Compressor Stages 17 17 17
Turbine Stages 3 3 3
Maximum Diameter (Inches) 38.3 39.1 38.3
Length (Inches) 208.5 208.7 208.4
Dry Weight (Lb.) 3,695 3,855 3,699
Power Specifications
Specific Fuel Consumption at Max Power 1.93 1.93 1.94
Max Power at Sea Level 17,000 17,820 17,000
Overall Pressure Ratio at Max Power 12.9 13.4 12.9

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Engine J85-5J J85-17A/B J85-21
Physical Dimensions
Compressor Stages 8 8 8
Turbine Stages 2 2 2
Maximum Diameter (Inches) 21 17.7 26.1
Length (Inches) 104.6 40.5 117
Dry Weight (Lb.) 584 400 684
Power Specifications
Specific Fuel Consumption at Max Power 2.2 0.99 2.13
Max Power at Sea Level 3,850 2,850 5,000
Overall Pressure Ratio at Max Power 6.7 6.9 8.3