Design work on a development of the liquid-cooled, V12 AM-35 with boosted supercharging and an intercooler positioned behind the supercharger began on the factory's initiative in December 1939. A batch of ten prototypes was completed in 1940 and bench-testing began on 5 January 1941. It passed its State acceptance trials the following April and was approved for production. It was tested in a variety of aircraft, but proved to be unreliable and prone to overheating. Factory No. 24 in Moscow built only twenty-nine AM-37s, as the new engine was designated, in 1941 before the German advance forced the factory to evacuate in October. Mikulin had been unable to resolve the issues with the AM-37 in the meantime and production was not resumed.
Planned version to be tested in February 1940, but no information if it was tested or it was even completed. 1,600 hp (1,200 kW) and a weight of 850 kg (1,870 lb).
TK for toorbokompressor. Planned version with a turbocharger.
P for Pushechnyy or cannon. A 1940 project for a model with an autocannon mounted in the space between the cylinders, firing through a hollow reduction-gear shaft.
Am-37u/v or AM-37UV
UV for udlinyonniy val or lengthened shaft. An engine with a lengthened shaft and remote gearing for use in the Gudkov G-1 fighter that carried the engine behind the pilot. Ordered developed in 1940 and design work started in 1941, but it was not completed.
Type: supercharged, liquid-cooled, V12 engine
Bore: 160 mm (6.3 in)
Stroke: 190 mm (7.5 in)
Displacement: 46.66 l (2 in)
Dry weight: 885 kg (1,951 lb)
Designer: Alexander Mikulin
Supercharger: single-speed geared centrifugal supercharger
Cooling system: liquid-cooled
Power output: 1,500 hp (1,119 kW)
Compression ratio: 7.0:1
Power-to-weight ratio: 0.77 hp/lb (1.26 kW/kg)