MiG-21.de

Engines of the MiG-21

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
R-11F-300 (37F)	F, F-13, U	38,2 / 53,4
R-11F2-300 (37F2)	F-13, PF, FL	38,7 / 60,0	F-13 refitted
R-11F2S-300 (37F2S)	PF, PFS, PFM, R, S, M, US, UM	38,2 / 60,6	with blown flaps (SPS)
R-11F2SK-300 (37F2SK)	MF	38,2 / 60,6	with nozzle correction device KDS
R-13 (95)	M, MF, RF, SM, SMT, UM	39,9 / 63,7	M refitted, UM also refitted
R-25 (25)	bis	40,2 / 69,6	thrust 97,1kN with special regime at low level

* without / with afterburner

Engine of the first MiG-21 generation: R-11.

R-11 (part cutaway) from the left ...

... and from the right.

Externally the R-11 can be distinguished by its radially arranged flame stabilizers of the afterburner.

R-11 complete with afterburner.

The R-13 differs from the R-11 in having grooved inner surfaces of the engine housing, ...

... seen here from the other side, ...

... and a combination of star-shaped and circular flame stabilizers. (Photos R-13: author's collection)

The R-25 also boasts grooved inner surfaces of the engine housing, but there are fewer rotor blades than on R-13 (21 instead of 24).

The flame stabilizers of the R-25 are of circular shape.

Not an engine in the true sense of the word: booster rocket SPRD-99 (seen here on a Finnish MiG-21bis).

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 R-13-300

* with / without afterburner

The WP-7 differs from the Soviet engines in a special combination of circular and star-shaped flame stabilizers.