Mikulin AM-34 - Variants

Variants

M-34

First production version. Direct drive. Early engines used imported Zenith 90R carburetors, although later ones used indigenous K-34 carburetors. In production until the end of 1939. Rated at 800 hp (600 kW) with a weight of 680 kg (1,500 lb).

Coupled M-34

Two engines driving one propeller, project for the Kalinin K-7, no production.

M-34F

small batch built in 1933 with a rating at 830 hp (620 kW).

M-34R

R for Reduktor or reduction gear. Rated at 800 hp (600 kW) with a weight of 670 kg (1,500 lb). Passed its State trials in May 1933 and in production from the end of that year to the end of 1939.

M-34RD

D for Dal'niy or long-range. Ten engines built with special attention to quality, smaller tolerances and K-34RD carburetors to equip the Tupolev ANT-25 record-breaking aircraft. RPMs were boosted to give a power of 830 hp. Later fifty more were built to power Tupolev TB-3 bombers converted to VIP transports.

M-34N

N for Nagnetatel' or supercharged. Development began in 1931 of this direct-drive model, but the first two-stage supercharger design proved to be quite unreliable. A single-speed replacement was developed at TsIAM and tested in November 1933 and production began in September 1934. The centrifugal type supercharger was designed as a removable module and could be installed on other versions of the M-34. Rated at 820 hp (610 kW). A PTK steam-powered supercharger was developed and tested from 1938 to 1940, but was not accepted for production.

M-34RN

This geared model used the same geared centrifugal supercharger (GCS) as the M-34N and had the same rating. It failed State testing in September 1934 when the pistons burned through.

M-34NA

A version of the M-34N with minor changes to some components to extend service life. It had the same power as the original model.

M-34RA

A version of the M-34R with the same changes and power as the M-34NA.

M-34RNA

A version of the M-34RN with all the changes introduced on the NA and RA models. Same power as before, but weighed 748 kg (1,650 lb). Flight-tested on a TB-3 in May 1935 and production began at the end of the year.

M-34NB

The NA fitted with a strengthened crankcase, a lightened crankshaft with a modified nose and a refined supercharger. The power remained the same, but the weight dropped to 638 kg (1,410 lb). A TK-1 turbocharger was tested with the prototype on a Polikarpov R-Z in 1936.

M-34RNB

A geared equivalent of the NB model with a lightened reduction gear. The power remained the same, but the weight dropped to 725 kg (1,600 lb). In production from October 1935 until the end of 1939.

M-34P

P for Pushechniy or cannon. A version of the M-34RN adapted to mount a autocannon in the V between the cylinder banks that fired through a hollow gear shaft. The specification was issued in August 1934, but no further information is known.

M-34NV

NV for Neposredstvenniy Vprysk or fuel-injected. It passed its bench tests in 1935 and was flight-tested in 1937, but was not accepted for production. Rated at 985 hp (735 kW).

M-34RNV

Geared version similar to the NV.

AM-34RNV-TK

Prototype built in 1938, similar to the RNV with the addition of a TK-1 turbocharger. Rated at 850 hp (630 kW) and an estimated weight of 810 kg (1,800 lb).

AM-34RS

Prototype built in 1938 with mixed cooling; air-cooled sleeves and ethylene glycol-cooled cylinder heads. Rated at 1,200 hp (890 kW).

AM-34NF

Prototype with a geared centrifugal supercharger and a TK-1 supercharger. Flight-tested in a TB-3. Compression ratio of 6.6:1 and rated at 985 hp (735 kW).

M-34N2B

A prototype with a supercharger, two turbochargers and four K-4 carburetors. Rated at 1,030 hp (770 kW).

AM-34FRN

F for Forsirovanniy or boosted. Development began in 1934, but development was not completed until 1938. The crankshaft, crank case, gearing and the side joints of the connecting rods were reinforced. The lubrication system was modified, the supercharger improved and a new gas-distribution system was fitted. The carburetors were moved to behind the supercharger. Rated at 1,200 hp (890 kW) and the weight dropped to 690 kg (1,500 lb). It was exhibited in the 1937 Paris Air Show.

AM-34FRNA

First main production version of the FRN model. Equipped with four carburetors.

AM-34FRNB

Next production model of the FRN. Equipped with six carburetors. A small batch was adapted for the ATsN-2 system with pressurized air provided by an external supercharger and flight-tested in a Pe-8 in 1938–39.

AM-34FRNV

The last main production variant of the AM-34. Built during 1938–39. The crankcase was modified and bronze bushings were used for the main supports. It had a longer crankshaft nose, four K-4 carburetors, and a modified lubrication system. The valve castings were made of magnesium alloy. The power remained the same, but the weight increased to 763.5 kg (1,683 lb). Variants with fuel injection and two TK-1 turbochargers were tested, but not put into production.

AM-34RB

Superchargers were removed from AM-34RNB engines during 1938–39 to create this model.