AM-38

The engine was created at the initiative of Mikulin as a low-altitude motor with a take-off power of 1625 hp, specially designed for use on attack aircraft. The creation of the AM-38 motor was another strategic breakthrough in the domestic motor industry. Since a high altitude engine was not required for the attack aircraft, its drive centrifugal supercharger did not require the selection of significant power, which was equivalent to obtaining a power increase on the motor shaft. With the outbreak of war, an inevitable aggravation of problems with the supply of high-octane gasoline was expected. Mikulin, when creating the AM-38 engine, acted farsightedly and reduced the compression ratio to 6.8, which allowed the use of fuel with a lower octane rating.

Work on the prototype AM-38 was started without a corresponding government decree. Only later did the decree come out: 1. Put in the factory No. 24 the production of AM-38 motors with a rated power of 1,500 hp. since January 1, 1941. 2. Conduct joint tests of AM-38 on January 15, 1941 (Test bench completion by February 1, 1941).

Since the AM-38 was created on the basis of the AM-35A motor, its drawbacks were inherent in it. In order to increase the resource from 50 to 100 hours, I had to go to design changes. In June 1941, the engine satisfactorily passed 100-hour state tests.

In the order of the People’s Commissar of the Aviation Industry No. 518 of June 13, 1941, it was noted that a government decree of June 10 took note of the statement by the chairman of the commission for state testing of the AM-38 motor Levin, chief designer Mikulin and the director of the plant Zhezlov that the motor was AM-38 satisfactorily passed 100-hour state tests and can be put into mass production, as well as that the AM-38 motor with a 100-hour resource is 30 kg heavier than a motor with a 50-hour resource. The order ordered from June 22, 1941 to begin production of AM-38 motors with a service life of 100 hours.

Initially, the AM-38 series motors had a number of serious defects, the main ones being cracked blocks, burnout of pistons and valves, mass failure of spark plugs, increased wear of screw gears in the gas distribution drive, etc. These defects were eliminated by making changes to the motor design the process of finishing it.

A powerful low-altitude motor turned out to be fit not only the IL-2. Armed designers Venevidov and Mozharovsky proposed to equip them with their own version of the BS-MV attack aircraft. AM-38 was also planned to be used on the twin-engine attack aircraft Il-6 . At the initiative of the Air Force in 1941, an AM-38 motor was installed on one of the serial MiG-3s. The plane was tested in the LII NKAP since August 19, 1941. The second experimental version of the MiG-3 aircraft with an AM-38 engine was built at the Mikoyan Design Bureau. He demonstrated unique speed characteristics at altitudes of less than 4000 m. The take-off properties of the aircraft improved slightly, but the maneuverability characteristics of the aircraft turned out to be low, although somewhat better than the serial machine. A small number of such aircraft with two synchronous ShVAK cannons in 1942 took part in the battles near Stalingrad.

Shortly after the outbreak of war, engine plant No. 24 was evacuated to Kuibyshev. Most of the design bureau of A. A. Mikulin also went there. The remaining, engaged in promising developments, were brought into several brigades and sent to the existing engine-building plant No. 19 in Perm. The main part of the OKB team, evacuated together with the serial plant No. 24 in Kuibyshev, was headed by Mikhail Romanovich Flissky. About half of the designers were forced to deal with the problems of mass production, the rest in difficult conditions were engaged in the construction and installation of exported equipment. Nevertheless, already in January 1942, the OKB resumed intensive work on the forced version of the engine for the attack aircraft, which received the name AM-38F. In May 1942, Mikulin's design team completely moved from Perm to Kuibyshev.

AM-38F (forced version of AM-38) - designed specifically for the two-seater version of the Il-2 attack aircraft. Installed on serial since 1943.

• Had an increased by 100 hp (up to 1700 hp) power on takeoff
• I had the opportunity to work for at least 10 minutes at altitudes of up to 1.5 km on takeoff mode.

Back in early 1942, A. A. Mikulin began work to increase the take-off power of the AM-38 motor to improve the take-off qualities of the attack aircraft. Due to boosting the engine by boost and speed, it was possible to increase take-off power by 100 hp. A new version of the motor was called AM-38F. The supercharger pressure was increased and the revs increased. The cylinder head began to be cast from silumin.

Like the unforced version, the AM-38F motor was developed by Mikulin on an initiative basis. The AM-35A engine was taken as a basis, its parts and components were strengthened accordingly. But if all the design documentation was first developed for the AM-38 motor, and then its manufacture was made, then the AM-38F was built in two copies without preliminary development of the entire volume of working drawings, according to the sketches! At a meeting in the Kremlin, Stalin demanded that Shakhurin and Mikulin develop the drawings in an incredibly short time - for 3 months, and in April 1943 start mass production of the motor.

At the end of February 1943, the Mikoyan Design Bureau was tasked to develop and build a small series (six copies) of the improved MiG-3U (I-230) fighter with an AM-35A engine. Since the AM-35A motors were not mass-produced then, it was decided to assemble them from the parts of the AM-38F motor. Six MiG-3U built, the first car took off on May 31, 1943. However, special successes with these aircraft could not be achieved.

In December 1941, Mikulin put forward a completely original idea about using a piston engine as a gas generator for converting the thermal energy of the exhaust gases of a motor in special turbo-reactors. A gas turbine coupled to the propeller shaft through a gear reducer made it possible to convert the energy of gases into additional power. According to Mikulin’s calculations, one could expect at the same time to obtain a power increase of 30–50% and at the same time achieve a reduction in specific fuel consumption.

Mikulin informed Stalin about his new idea with encryption, suggesting that it be implemented on AM-37 and AM-38 engines. Shakhurin supported the idea and gave appropriate orders to Mikulin and the factory director Zhezlov. The idea was another major achievement in the direction of a radical increase in the specific power of piston engines, but due to technological difficulties during the war, it was not possible to realize the idea of ​​Mikulin. It was embodied in heavy duty piston engines developed after the war by A. D. Shvetsov and V. A. Dobrynin.

During the war, plant No. 24, together with TsIAM, carried out work to increase the height of the AM-38 motor to 8000 m by using the TK-3 turbocompressor, the development of which was promoted by a prominent scientist V. I. Dmitrievsky. The rated power of the engine with the TK-3 at the estimated height was 1,500 hp. It was planned to use such motors on the second version of the twin-engine “point defense fighter” P.O. Sukhoi. In June 1944, designer V. G. Ermolaev worked out a version of the Er-2 aircraft with an AM-38 engine and a TK-3 turbocharger. The calculated flight data of the aircraft turned out to be very good: the maximum flight speed of 550 km / h, the flight range with a bomb load of 1000 kg was 4000 km, and the practical ceiling was 11 000 m.

This work of the Mikulin Design Bureau laid the foundation for the creation of effective power plants for high-altitude aircraft based on low-altitude engines with high take-off power and allowed Mikulin to successfully develop such systems at the end of the war and immediately after it for stratospheric fighters and high-altitude bombers.

• L. Burne, V. Perov. Alexander Mikulin: a man of legend . - "Engine".
• AM-38F on the site " Corner of the sky "