|Function||Experimental Fighter||Pre-series Fighter|
|Power at 0m, nominal||1250hp|
|Power at 2400m, nominal||1350hp|
|Weights and loads|
|Gun Type||ShVAK 20mm|
|Position||Through the spinner|
|Gun Type||UBC 12.7mm|
M-106 (also known as M-106-1sk) was a M-105PF variation. Major distinction - single-speed centrifugal supercharger, providing intake pressure 1175mm.Hg. As a result, engine gained up to 150hp of output. The supercharger was designed by V.A.Dollezhal.
Other engine changes included:
Single-speed supercharger allowed to eliminate a power drop at 1850m, where M-105PF supercharger had a speed change. Elemination of this power drop (known to and exploited by Luftvaffe pilots) could provide Soviet pilots with certain advantage at low and medium altitudes, where most of dogfight took place.
Airframe modifications were minor weight saving changes and installation of the VISh-61P variable-pitch propeller. Yak-1 M-106 had fuselage of series Yak-1 (which one? - A.S.), metal tail stabiliser and rudder from Yak-7, metal wing spars, two wing fuel takns. Oil coolers (9' diameter) were installed in wing tunnels. Tunnel of the water cooler was modified according to recent TsAGI recomendations.
Yak-1 M-106 was armed with engine-mounted 20mm ShVAK and 12.7mm UBS guns. Other equipment was identical to series Yak-1 M-105PF.
Engine progressed slowly, and only on December 12, 1942 assembly of test fighter was ordered by GKO. Yak-1 M-106 was assembled in end of December, 1942. In January 1943 trials were undertaken by test-pilot A.I.Kokin, seniour engineer K.N.Mkrtychan and aircraft mechanic F.Z.Sbitnev.
Flight performance obteined during factory trials was substantially better than of series Yak-1 M-105PF. But... those advantages could not be obtained at air temperatures above 15°C. Cooling system productivity, despite was increased compared to standard M-105PF, could not coup with increased engine heat outpup on maximum climb rate.
Factory trials revealed also that the engine needs more work on it. Vibration on transitional (1800 to 2000rpm) rates, frequent spark plug failures, smoke, excessive fuel consumption and 'diseling' required serious attention of engine designers. It was transferred to LII.
Also in January (8 to 13) 1943 another Yak-1 with M-106 engine was tested at LII. This was a seruies Yak-1 M-105PF with standard airframe. It had lower assembly quality and was heavier than specially-built modified stblemate. Performance worsened, and engine had same toothing problems.
Monetheless, production of the Yak-1 M-106 was launched. 47 aircraft were assembeld at Saratov until February 18, 1943. 32 of them had standard cooling system and were designated for winter conditions combat trials. But this was the end of the story. None of those machines saw action, because all were rejected by military representatives. Temperature regimes were found not acceptable, M-106 engines were graded as unsuitable and replaced by standard M-105PF.