Shvetsov M-25

The Shvetsov M-25 was an aircraft radial engine produced in the Soviet Union (USSR) in the 1930s and 1940s, a licensed production variant of the Wright R-1820-F3.

The first M-25s were produced from kits imported from the United States; the main difference between the later M-25 and the R-1820-F3 was the use of metric components.

13,888 M-25s were produced in the USSR at factories in Perm and Kazan.

There were a number of sub-variants which differed from the original M-25 in that they had reduction gears, rather than direct drive.

The M-70, a twin-row 18-cylinder engine, eventually developed into the ASh-73 which powered the Tupolev Tu-4, an unlicensed, reverse-engineered copy of the Boeing B-29 Superfortress.

Family tree of Shvetsov engines