Three generations of engines with several subversions were built in the MiG-21 during 25 years of manufacturing. Because of the limitations set by the fuselage there were only minor external differences between the different generations.
| Engine | Versions | Thrust (kN)* | Remarks |
|---|---|---|---|
| R11F-300 (37F) | F, F-13, U | 38,2 / 53,4 | |
| R11F2-300 (37F2) | F-13, PF, FL | 38,7 / 60,0 | F-13 refitted |
| R11F2S-300 (37F2S) | PF, PFS, PFM, R, S, M, US, UM | 38,2 / 60,6 | with blown flaps (SPS) |
| R11F2SK-300 (37F2SK) | MF | 38,2 / 60,6 | with nozzle correction device KDS |
| R13 (95) | M, MF, RF, SM, SMT, UM | 39,9 / 63,7 | M refitted, UM also refitted |
| R25 (25) | bis | 40,2 / 69,6 | thrust 97,1kN with special regime at low level |
* without / with afterburner











Engines of the J-7 / F-7
Like the MiG-21 its Chinese copies were fitted with externally almost identical engines of different generations.
| Engine | Versions | Thrust (kN)* | Remarks |
|---|---|---|---|
| WP-7 | J-7I, F-7A | 38,2 / 53,4 | |
| WP-7B | J-7II, F-7B, JJ / FT-7 | 38,7 / 59,8 | |
| WP-7BM | F-7M / P | 40,2 / 59,8 | |
| WP-7F | J-7E | 44,1 / 63,7 | |
| WP-13F | J-7III, F-7PG | 44,1 / 65,9 | similar to R13-300 |
* with / without afterburner
