Author Topic: Question re Russian avgas (Read 726 times)

Squire · « **on:** October 26, 2005, 02:37:28 PM »

Did a search and couldnt find the answer, so, if you dont mind, what octane did VVS gas have?

87?

100?

The Ki-84 thread got me wondering, as posters were commenting on Japanese fuel quality.

LLv34_Snefens · « **Reply #1 on:** October 26, 2005, 03:10:50 PM »

In 41-42 it had an octane rating of 70-75.

Squire · « **Reply #2 on:** October 26, 2005, 03:16:44 PM »

Yikes, that is low, any idea what it was 44-45?

gripen · « **Reply #3 on:** October 26, 2005, 03:46:57 PM »

At least the Klimov M-105 required 95 octane fuel.

gripen

Tails · « **Reply #4 on:** October 26, 2005, 04:05:11 PM »

Quote

Originally posted by LLv34_Snefens
In 41-42 it had an octane rating of 70-75.

That IS low. Might that have limited the range of some Russian aircraft? Because of running rich to prevent detonating?

Tilt · « **Reply #5 on:** October 26, 2005, 04:56:58 PM »

Ash 82 FN used on La5FN and La7 used 4B-78 fuel with a minimum octane level of 95.

dankes · « **Reply #6 on:** October 27, 2005, 07:52:58 AM »

A gift for everyone interested

[Engine Type] [Fuel Mk (Octane #)]

[M105PF] [4B-78(95)]
[M105PA M105ÐA M105] [3,5B-78 (94)]
[M103A] [3,5B-78 (94) 1B-95 (96)]
[M103] [3B-74(91) 2B-78 (91) B-95 (94-95)]
[M100 M100A M100AÓ] [2B-70(85)]
[AM38] [4B-78(95)]
[AM35A] [4B-78(95)]
[AM34FRNV] [3B-78(93) 4B-74 (92) B-95 (94-95)]
[AM34RNV AM34N AM34RN M17] [2B-70(85)]
[M17] [B-70(70)]
[M88B M88] [3B-78(93) 4B-74 (92) B-95 (94-95)]
[M87B M87A M86] [2B-78 (91) 3B-74 (91) B-95]
[M85] [3B-70(87)]
[M82] [4B-78(95)]
[M63] [3B-78(93-94) B-95 (94-95)]
[M62] [3B-74(91)]
[M62IR M25 M11] [3B-74(91) 3B-70 (87) ARB-70 (70) KB-70 (70)]

dankes · « **Reply #7 on:** October 27, 2005, 07:54:18 AM »

Quote

Originally posted by dankes
A gift for everyone interested

[Engine Type] [Fuel Mk (Octane #)]

Orginal thread here http://vif2ne.ru/nvk/forum/3/archive/404/404924.htm

in Russian

Tilt · « **Reply #8 on:** October 27, 2005, 09:11:20 AM »

Klimov 107? per Yak9U ?

dankes · « **Reply #9 on:** October 27, 2005, 09:26:39 AM »

Quote

Originally posted by Tilt
Klimov 107? per Yak9U ?

This info was originally extracted from the aircraft engines reference published in 1943

I suspect same as for M105PF2. AFAIR 107 had lesser compression ratio and significantly higher rpms

Squire · « **Reply #10 on:** October 27, 2005, 12:14:50 PM »

Looks like @95 octane was a standard fuel then, from those #s, with a few exceptions.

I would be interested to know what types of RAF and USAAF lend lease machines did good or not so good with that fuel. Just for info. I have never read anything about that specifically. Certainly the P-39 had no problem.

gripen · « **Reply #11 on:** October 27, 2005, 01:12:27 PM »

Here is an article, I can't decide if it's just a commercial or historical facts but a good read anyway

The Russian fuels seem to be rated just at weak micture so it's difficult to say if the rich rating was close the US or UK fuels.

FAF used 87 octane + some amount of alcohol with the M-63 and M-105. Another way was to mix 87 and 100 octane fuel to get about 95 octane fuel.

gripen

Tilt · « **Reply #12 on:** October 27, 2005, 01:29:23 PM »

I had an article somewhere about a fuel additive that the VVS had to use for lend lease merlins............

Squire · « **Reply #13 on:** October 27, 2005, 01:54:35 PM »

Thanks, very interesting article.

dankes · « **Reply #14 on:** October 28, 2005, 01:40:01 AM »

A bit about soviet fuel Mks

4B-78(95) is a mixture of base gas with octane 78 and 4 cubic cms of tetraethyl lead (called R-9) per liter of base gas with effective octane # 95.

From the several cobra (and other lend-lease crafts) pilot's stories, planes were nearly always fueled with lend-lease 95- and 100- octane fuel, at least from the mid 42.

I have no figures though how much lend-lease fuel were delivered.