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AM-35A and AM-37

A.A. Mikulin



In 1938 AA Mikulin design team was developed a more powerful engine AM-35 and AM-35A, based on a completely successful development and implementation of a series motor AM-34 (AM-34FRN).

The first in April 1939, passed state testing engine AM-35, which was originally designed for installation on the TB-7 instead of the AM 34FRNV. The estimated height of the AM-35 was extended to 4,500 meters, the nominal power at this altitude - up to 1200 hp

To obtain high power and altitude AA Mikulin applied to AM-35A supercharger with high boost pressure (1040 mm. Hg. Cent.). Serials TB-7 were equipped with AM-35A (along with diesels M-40F and M-30) from spring 1941.

In the 1940 made lapping AM-35A engine. At the same time, AM-35A engine was installed on the armored attack aircraft BSh-2 prototype design SV Ilyushin.

Note that designers NN Polikarpov and SA Kocherigin faced serious cooling problems motors when creating the first armored stormtroopers. These problems are even more acute when creating BSh-2 aircraft. OKB Ilyushin long time trying to solve this problem on its own and ignored the experience of engine design bureau.

Very emotional Mikulin described the situation in his speech at the meeting in NCAP at September 1940: "... All the power plant is a his (Ilyushin. - Ed.) invention, is not based on previous experience. When my very responsible representative came and said that the engine can not run without a single hole for blowing the power plant, he said, "Go, you can't help us."

AM-35A engines were installed as the experienced fighters I-200 (MiG-1 and MiG-3). In the draft design of the fighter "K", developed by NN Polikarpov, provided for the installation of improved motor AM-37, and, subsequently, its modifications, called AM-39 . AM-37 engine was not brought to the series, the work on the AM-39 engine were just beginning in 1940.

AM-35A engine was put into mass production at the end of 1940. The AM-35A engine had a rated power of 1200 hp on the estimated height and a maximum capacity 1400 hp on the 4750 m altitude for 20 minutes . This result has been outstanding for 1940.

The AM-35A altitude engine on test aircraft I-200 allowed to reach flying speed 656 km/h at an altitude of 7000 m; the MiG-3 aircraft of subsequent production at this altitude has a top speed over 610 km/h, easily outdistancing other fighter types, and both domestic and foreign. But at first the view was that the AM-35A is not a "fighter" motor. In general, such a division of motors on the fighter and bomber was not justified. Take, for example, engines "Merlin" and "Allison" V-1710.

Presented Mikulin AM-35A engine for the award to them. VP Chkalov. The prize was not awarded to him, but soon he was awarded the title of winner of the Stalin Prize.

When introducing the AM-35A engine had to deal with the solution of some problems.

In the spring of 1941 at the motor AM-35A revealed a serious flaw. In line units have been several accidents. To find ways to eliminate failure left a month. During this time, have been banned flights of MiG-3, TB-7 with AM-35A, as well as experimental machines. Soon motors equipped with a new mechanical device control vanes.

At the end of 1940 engines AM-35A was equipped experienced bomber DB-240; design VG Ermolaev. AM-35A was significantly heavier than the M-105 (230 kg) and had a higher specific fuel consumption (285-315 g/h l.s.h against 270-288 g/h l.s.h of M-105), but the increase in power was decisive in the selection. Later found a more promising version of this aircraft with engines AM-37.

During the mass production of AM-35A engine was a question of choosing the most efficient degree of reduction of the motor. As a result of tests conducted at FRI, it appeared that it was expedient that I-200 was 0.732 gear ratio. On airplanes, it is with such engines (and transmissions) reaches a maximum speed of flight.

Series production of the AM-35A engine was discontinued in late 1941, as the main reasons were removed from production the primary consumer - the MiG-3 ... and the need to increase production of engines AM-38.

Basic Data of Petrol Engines
M-105 AM-35A AM-37
Cooling method Liquid Liquid Liquid
Cylinders 12 12 12
Engine displacement, l 35 46.6 46.6
The Compression ratio 7.1 7.0 6.8
Gear ratio 0.59; 0.666 0.59; 0.732; 0.902 0.732
Take-off power, hp 1100 1350 1400
Rated power, hp 1050 1200 1400
On the estimated height, m 4000 6000 5800
Rated speed, r / min 2700 2050 2050
Dimensions (LxH in the midsection), mm 798 X 814 866 X 1082 866 X 1082
Motor weight, kg 600 830 830
Brand of gasoline 3,5B-78 4B-78 4B-78
Manufacturer's plant # 16, 26 # 24 # 24


In late 1940 - early 1941, the AM-37 was the most powerful domestic water-cooled engine, satisfactorily passed the factory 100-hour test. The rapid development in the series production of the new Mikulino "engine" guide NCAP considered a priority plant number 24 in 1941 is worth noting that the engine AM-37 AM and were built in series-35A were completely similar and interchangeable with each other on all nodes except for:

- AM-37 had an air-cooled heat sink to cool the air to the carburetor when the blower motor and the AM-35A instead established the so-called spacer, ie duct segment;

- AM-37 had an additional pump to pump water into the air-water radiator;

- Diameter of the impeller motor AM-37 was equal to 285 mm instead of 275 mm at the motor AM-35A.

In other words, the engine AM-35A could be relatively easily converted into AM-37, which improves take-off power to 1,400 hp, and operational - to 1250 hp at an altitude of 6000 m

October 20 2012


  • " Alexander Mikulin: a living legend" /Lev Berne; Vladimir Perov /
  • magazine "Aviamaster" #2 1999    /AN Medved; DB Khazanov/

October 18, 2012

Dear Sir,
I'm a student from Munich in Germany und i study aircraft engineering. I want to do a project work about the Mikulin-AM-35A. After a while of searching i found your side and your article (//airpages.ru/mt/am35.shtml). But my russian is not very good. So i want to know if it is possible to get a english (or german) translation.
Yours faithfully
Sascha Hermann

October 20, 2012
Hello, Sascha!
   Sorry, English is not my native language, so translation was done by Google translater.
   Regards, Vyacheslav.

October 20, 2012 Hello Vyacheslav
   I thank you very much for your work.
   Best wishes
   Sascha Hermann