ucon said:
Dear Thomas!
Il-26 project last only two years (1947-1948) and in Il DB they have studied 3 variants with the following engines:
piston ASh-2TK;
disel M-501;
purtoprop VK-2.
Regards
ASh-2TK and ASh-2K (ASh-4K) –
Four-row versions of the ASh-82, developed in the late '40s. The engine concept was similar to the Pratt & Whitney R-4360. The Shvetsov design bureau took into consideration all available information about the R-4360 and developed an engine with less maintenance operations, longer time between overhaul, direct fuel injection and a simpler supercharging system. The ASh-2TK had a two-stage two-speed supercharging system with intercooler (similar to the ASh-73) that compromised the engine's long TBO.
Finally the ASh-2TK was discarded and a new version was developed, the ASh-4K, with an experimental variable-speed turbocharger and after-cooler, which allowed a cruising altitude of 11,000 m (36,089 ft). The engine had 82.4 litres (5,030 cu in) and 4,000 HP (2,985 kW) at 2,600 RPM (dry). The Ash-2K (ASh-4K) version had 4,700 HP (3,507 kW) wet, with a water-methanol system. For political reasons, these engines were prematurely installed in Tupolev Tu-4LL testbeds at the end of 1950, when the prototypes' initial tests had barely begun. The engines had various teething and overheating problems, and required a long testing period. Most of the flaws were fixed in the mid-fifties, but the production was cancelled: in those days, the priority for the Soviet Air Force were the turboprop and jet engines.[7]
Yakolev slowed down work before this, believing his
M-501 diesel engine would be better for long-range bombers. Apparently this engine went on into series production for marine work -
seven blocks in radial, 42 cylinders. Sounds like another very interesting design!
Factory No.500 was headed by V. M. Yakovlev (no relation to the aircraft designer), who was hard at work on his own large diesel aircraft engine—the
6,200 hp (4,620 kW), 8,760 cu in (143.6 L), 42-cylinder M-501.Yakovlev was critical of the work done on the M-224;
he felt that the engine took resources away from the M-501. With little progress on the M-224, Yakovlev was able to convince Soviet officials that his engine had the greater potential, and all development on the M-224 was stopped in mid-1948.