Question for those expert in Bf109 G

[Eduardo]

Hello;

My first question is about the Me 109 G-5/ U2 /AS.Which type of fuel they used( C3 or 87) with the GM-1 sistem?
My second question is about the G-5 / U3 /AS.Was there any G-5 using the DB 605 ASM engine?

Eduardo.

[PaulEder13]

The Daimler-Benz DB 605 is a German aircraft engine, built during World War II. Developed from the DB 601, the DB 605 was used from 1942 to 1945 in the Messerschmitt Bf 109 fighter, the Bf 110 and Me 210C heavy fighters. The DB 610, a coupled "power system" powerplant comprising a pair of side-by-side configured examples of the DB 605, and geared together in the front to turn a single output shaft, was used in Germany's only operational heavy bomber, the Heinkel He 177.
License-built versions of the DB 605 were used in the Macchi C.205, Fiat G.55, Reggiane 2005 and some other Italian aircraft. It was also initially used in the pusher-design Swedish Saab J21. Approximately 42,400 DB 605s of all kinds were built.

[PaulEder13]

the 601, the 605 was designed to run on "B4" fuel, at 87 octane

[Eduardo]

At least 40% of all Me 109 G used C-3 type fuel ! I know that the MW-50 required C 3 fuel but... I´ve saw a photo of a G-5/ AS serial 110064 of Günther Specht with C-3 type fuel and I wounder If it had MW-50 or GM-1 system.


Eduardo.

[veltro]

Originally Posted by Eduardo

At least 40% of all Me 109 G used C-3 type fuel ! I know that the MW-50 required C 3 fuel but... I´ve saw a photo of a G-5/ AS serial 110064 of Günther Specht with C-3 type fuel and I wounder If it had MW-50 or GM-1 system.

The presence of GM-1 required the use of low-octane fuel (i.e 87 octane = B4). The fact that Specht's aircraft had a C3 (96 octane) indication, means that it had no GM-1 and most probably also no MW-50, since with the DB 605AS used B4 when MW-50 was installed.

The only exception was the DB 605ASC engine which could use C3 fuel with MW-50. This version however was built very late in the war, so I guess it is not the case of the G-5/AS flown by Specht.

IMHO, at least...

[Eduardo]

Thanks Veltro;

But ... If you look at Mercedes archiv about the DB´s engines you will see the use of "C-3" type fuel when using the MW-50 in "AS" engines. My
doubt about that has one reason. All Regensburg G-14 / AS which carries the MW-50 in the serial number blocks 783xxx 785xxx use the 'C-3" and big radiator with padle blade propeller , which was not the case of Specht plane .

Eduardo.

[olefebvre]

Originally Posted by Eduardo

Thanks Veltro;

But ... If you look at Mercedes archiv about the DB´s engines you will see the use of "C-3" type fuel when using the MW-50 in "AS" engines. My
doubt about that has one reason. All Regensburg G-14 / AS which carries the MW-50 in the serial number blocks 783xxx 785xxx use the 'C-3" and big radiator with padle blade propeller , which was not the case of Specht plane .

Eduardo.

The use of B4 along with MW-50 was cleared at a later date. The only issue with this configuration was the potential for breaking the engine in case MW50 supply was interupted while running at high ata.

[Eduardo]

Thanks... but what about Spech plane G-5 /AS using C-3 type fuel in early days,I mean around september 1944 ?? Some one told me once that the AS engine in a pressurized fighter would be DB605 ASO. Did this configuration riquires an C-3 type fuel??

Eduardo.

[Harri Pihl]

The early AS engine (spring 1944) apparently required C3 fuel, at least according to Valtonen's article on the As planes in SIHL. The AS planes of FAF used B4 though but that was later, summer 1944. September 1944 is late for the original AS engine, after all it was supposed to be just a stop gap solution for the high altitude until the delayded DB 605D is ready.

[George Hopp]

For what it's worth, the manual for the Bf 109G-AS (as of August 1944) and for the Bf 109 G-5 with GM-1 system (as of August 1944) both make no mention of fuel, so I assume it remained at B-4 (87 octane).

As an aside, the GM-1 manual mentions the need for care during take-off with the trim needing to be moved to 1 1/2 degrees nose heavy.