The M-105, designed in 1940, drew heavily onKlimov's experience with theHispano-Suiza 12Y (license-built as the M-100). In addition to a two-speedsupercharger, the M-105 had several improvements liketwo intake valves per cylinder and a counterbalancedcrankshaft. The M-105 was the first Klimov V-12 engine design to usereverse-flow cylinder heads, forcing the induction system to be placed on theoutside of the cylinder banks, with the exhaust system also exiting from the outboard side, with twin sets of "siamesed" exhaust ports adjacent to each other. About 129,000 M-105 and its variants were built.
During the war, Klimov's engines were redesignated from "M" (for "motor," engine) to "VK" for the lead designer's initials.
M-105 - (1,100 horsepower (820 kW)) First version produced at the end of 1939. Installed on some pre-war fighters.
M-105P - (1,050 horsepower (780 kW)) First mass production engine (1940). Able to accept amotornaya pushka (моторная пушка - motor cannon)-mountautocannon in the "vee" betweencylinder banks. Installed on the majority Soviet pre-war fighters - Yak-1, LaGG-1 and several experimental aircraft.
M-105PF (VK-105PF) - (1,260 horsepower (940 kW))1942 Modification with significantly increased power output at the expense of decreased high-altitude performance. In spite of Klimov's concerns about decreased service life, the engine was pressed into production at the insistence ofYakovlev, and further exploitation of "PF" version showed this was the right decision. The "PF" was installed on the most numerous versions of "Yak" fighters - Yak-1B, Yak-7B, Yak-9.
VK-105PF2 & PF3 - (1,300 to 1,360 horsepower (970 to 1,015 kW)) Further increase in power output, which was believed to have exhausted the potential of the M-105 design for greater performance. The "PF2" was installed in the Yak-3 andYak-9U.
Valvetrain: Two intake valves and onesodium-filled exhaust valve per cylinder actuated via a singleoverhead camshaft per bank. Valve lift: 13 mm (intake and exhaust)
Supercharger: Gear-driven two-speed centrifugal type compressor. Gear ratios: 7.78:1 (1st speed) 11.0:1 (2nd speed). Maximum boost for take-off: 965 mm Hg (38.00 MP), subsequent variants had 1,100 or 1,200 mm Hg. Maximum boost at altitude: 920 mm Hg (36.22 MP), subsequent variants had 1,100 mm Hg. Emergency boost (maximum 2 minutes): 1,100 mm Hg (43.30 MP) at 2,800 RPM. Critical altitude: 2,000 m (6,561 ft) at 1st speed, 4,000 m (13,123 ft) at 2nd speed.
Fuel system: Six K-105 Carburettors (License copy of Solex-Hispano 56SVC self-adjusted carburettor), three on each "outboard" side of cylinder banks
Fuel type: 94 (minimum grade), 95 or 100octane rating gasoline.[3]
^Valtion Lentokonetehdas (1943).Hispano-Suiza 12Y-31, M-103, M-105. Rakenneselostus, Käyttö – Ja Huoltoohjeet ["Valtion Lentokonetehdas" State Aircraft Factory: Hispano-Suiza 12Y-31, M-103, M-105. Use and Maintenance Instructions.] Helsinki: Maintenance and spare technical manual of the Finnish Government. The National Library of Finland.
^During the war, the Soviet Air Force used fuel mixtures, including automotive gasoline, without troubles.
