[Juha]

My contribution, in fact "Altea"'s

- Aviation (http://www.ww2aircraft.net/forum/aviation/)
- - Question on M.S.406 (http://www.ww2aircraft.net/forum/aviation/question-m-s-406-a-16642.html)

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Altea

10-23-2009 10:39 AM

…Soviets had no 100 octane fuel until late in war,except from Lend Lease deliveries. With standard 94 one (in fact real octane number 91-92)…Some pilots remember 100 octanes (blue) LL use in their front-line Yaks, with a 20 km/h speed gain and some overheating. But nothing official issued from soviet industry… the 3Б-78 (and 4Б-78 used on M-82) soviet fuels always had 93-95 (and 95-96) o. number from 1939, with some quality fall to 91-92 in some midwar deliveries…
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Altea

10-30-2009 06:23 AM

… The soviet 95 octanes fuel had exactly the behavior of a 95% iso-octane and 5% heptane mixture fuel on soviet CFR.

It (the 4B-78 ) was obtained by adding 4 cm cub of TEL to a natural 78 octanes kg raffinated from Bakou fuel. You can try owerdays, it’s still making 95 octanes by the same method.

Yaks were not using it, only M-82F/FN. The 2B-78 to 3B-78 mixtures for Klimovs 103A, 105, 106. And some 3.5B-78 for the M-107…
Germans were not using Eugène Houdry’s cracking methods, AFAIK. But soviets with american help, did. In 1943 they were building 6 such a reffineries under licence. So late in the war they had 95 (soviet number) basis fuels that could provide from 96 (1B-95) to 115 (4B-95) octane number fuels.

In 1942-1943 soviet fuel qulity had failed, because of , grozny , majkop production 78 basis reduction. Spits and Airacobras were simply using LL fuel supplys, if they were not derated.


- Aviation (http://www.ww2aircraft.net/forum/aviation/)
- - The use of 100 Octane Fuel in the RAF pt 2 (orum/aviation/use-100-octane-fuel-raf-pt-2-a-20108.html)

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Altea

11-05-2009 12:25 PM

Quote: Originally Posted by Nikademus (Post 568278) "Soviet fighter pilots found the British Hurricane to be outdated and cumbersome. Furthermore, the standard Soviet aviation fuel in 1941-42 was the B-70 formulation, with an octane rating between only 70 and 75. Since the Hurricane's Rolls-Royce Merlin engine was designed for a considerably higher octane rating the Soviet fuel wore them down rapidly, decreasing preformance and frequently causing flight accidents." Source: Black Cross/Red Star Vol II. (p.32)

Frankly, if being rigorous as an historian i won't prise Christer Bergstorm for his technical level, rather low...Soviet used natural refined fuels with B-59 to B-78 octanes marks, with some 1 to 4 cm cub TEL additives, that makes octane numbers quoted here:

TEL 1 2 3 4
Б-59 73 78 81 82
Б-70 80 85 87 88
Б-74 85 88 90 92
Б-78 87 92 93 95

So 3B-70 makes 87 octane numbers, so for 1.5B-74 or 1B-78.

Your Pe-2's Klimovs 105 worked on 91-95 octanes fuel that ranges (the highest being the best for safe margin) from 3.5 - 4 B-74 to 1.5 - 3.5 B-78.

The mark 75 never existed in soviet standards. (X) B-59 was mainly used in cars or old planes as R-5, Po-2, R-Zet...

Of course, LL deliveries were also massively* used, and some local made B-95 that could gave 96-115 octane numbers at the war's end, using Houdry's cracking methods (Shell patent).

* some sources quote 2 620 thousand tons!

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I recall reading years ago, that one of the USSR's main offensive in 1944 was delayed a few days/a week on Stalin's order in order to get LL 100 oct fuel for a P-39 fighter division, which Stalin thought would make an important contribution to the air part of the offensive.

Juha