Kharkiv model V-2
The Kharkiv model V-2 () was a Soviet diesel tank V-12 engine, the V angle at 60°, designed at the Kharkiv Locomotive Factory by Konstantin Chelpan and his team. It is found in the BT-7M (BT-8), T-34, KV, IS and IS-10 (T-10) tanks, and by extension, the vehicles based on them, such as the SU-85 and SU-100 tank destroyers based on the T-34 and the ISU-122 and ISU-152 self-propelled guns based on the IS-2. Throughout its production life, output ranged from roughly 450-700 hp. The engine was made of aluminium. The engine cooling system  was liquid, of a closed type. It included a water jacket of the cylinder blocks; water radiators; a water pump; a centrifugal fan; a t-valve with steam and air valves, and piping. The cooling system capacity was 90- 95 liters. The radiators were connected to the surrounding air via an air valve. The t-valve, leading to both radiators, was designed for filling the cooling system with coolant. Displacement , bore , stroke left cylinder group and right cylinder group, torque . History of development and production. The V-2 started development in 1931 until 1939 by design team of the diesel department  of the Kharkiv Locomotive Works, first under the leadership of Konstantin Chelpan, who was arrested in 1938. Work was passed down to his deputy for project work, Yakov Efimovich Vikhman, and Ivan Yakovlevich Trashutin, his deputy for experimental and production work, who completed development of the engine in 1939. Near the end of the 20th century, the V-2 was fitted with more modern modifications by the chief designer of the head design bureau for the Chelyabinsk Tractor Plant, Vladimir Ivanovich Butov. Serial production for the V-2 begun on September 1st, 1939. The Red Army adopted the V-2 engine in the  same year in three modifications: the V-2 (500hp), the V-2K (600hp) for the KV line of tanks and the V-2V (375hp).