Svenska Flygmotor AB started the Mx project during the summer 1941, intended for the Jx and Bx fighters, to be ready in 1947.
Its configuration would have been "two V-12s"
in an X-configuration.
Diameter 1.28 m, 54 litre stroke volume,
injection pump, overhad cams,
turbo compressor, power up to 2500 hp.
Devepment plan: 1 and 4 cylinder test engines ready by May and June 1944, 24 cylinder by 1945.
Svenska Flygmotor were occupied with producing the STWC3 and DB 605, so the first series engines couldn't have been produced until 1949.
The 1 cylinder test engine became the start of the 1000 hp F12, which was the first engine for the Strv 103 "S"-tank.