First, do you have anything to back that up ? Uhm, the answer is "no" as usual.
Yes, a Luftwaffe document showing fuel allocation to 5 JGs. Do you have any
German documents to refute it? We're not talking about
Italian planes, after all.
The "all/most C-3 went to FW 190 units" myth. As usual, we don`t see any proof to that.
From Butch2k:
"C3 was necessary for the 190 equiped units whose engine could not run without. So it seems that in the last months of the war G-10 and K-4 units were delivered B4 instead and had to rely on B4+MW-50 rather than C3+MW50."
He then followed it up with a document showing allocation to Stab, I and III JG52, Stab, I, II and III JG 77, Stab, I, II, III and IV JG300, Stab, I, II, III and IV JG301 and II and IV JG1.
Aircraft types were 109G6, G10, G14, K4 and FW 190 A8, A9.
Every single gruppe is running B4 in the 109s, C3 in the 190s.
Do you have any documents showing the 109K4 gruppes using C3? Note I only claimed most C3 went to the 190s, but so far the only direct evidence shows only B4 going to the 109s.
IT IS ABOUT NOTHING ELSE ! There`s no research behind these statements,
I'm not much of a researcher, but I'd say Butch was, and the info and doc I repeated above stand against your claims to the contrary, backed up by deliveries to
Italian units. You haven't provided any evidence about
Luftwaffe use late war.
Isegrim, everyone else agrees the Luftwaffe faced a desperate fuel situation late war. It makes sense that they would send C3 to the 190s that couldn't fly without it, and B4 to the 109s that could make do with it.
Need more ? Nashwan did not provided any. I can. Read the British report on a captured G-14. This plane uses DB 605 AM, and has the same 1800 whatever fuel is used. B-4 or C-3. Read again : whatever fuel, 87 octane B-4 or 96 octane C-3 is used in mix with MW-50, they will get the exact same power output. There`s no advantage using C-3 instead of B-4.
Isegrim, what power output is used for your 109K4 speed and climb charts? It's not 1800 ps, is it?
It's 2000ps, which was available only with
C3 and MW 50. Do you want to dispute that? We're not talking about 1800 ps, we're talking about 2000ps, which is the figure you use in your peformance charts.
And besides, what part in the British report says 1800 ps is achieved with B4?
Yet the British found the following in the relevant part of description, Me109G-14 W.Nr. 413601, captured in 1944 :
Isegrim, this plane was captured on the 22nd of July 1944. We are talking about the Luftwaffe fuel supply in 1945. Think there might be a difference in the Luftwaffe's fuel situation in the final months of the war? Everyone else does.
As for the "1.98ata was not authorized until February 1945" claim... not much needs to be said. The DB 605D`s manual, 3rd edition, dated 1st December, 1944, says 1.98 IS AUTHORIZED. PERIOD.
There's a cleaned up pdf of the 109K4 manual available on the net. It's the December edition. It says the manifold pressure guage only goes up to 1.8ata:
1. Ladedruckmesser
Der Ladedruckmesser mit einem Meßbereich von 0,6 bis 1,8 ata ist unten
rechts im Gerätebrett eingebaut. Die Druckmeßleitung ist an das Laderrohr
des Motors angeschlossen und durch die Rumpfstirnwand geführt.
Now, what Butch had to say about 1.98ata on the 109:
Isegrim you are very wrong on this point, it took a lot of time to clear 1.98 ata boost for operational use.
Indeed operational tests began in January 1945 with just one gruppe, and it seems it was cleared for use by all gruppe in March 1945.
"Schwarze man" then reffered to the manual he'd sent to Butch, who replied:
Yes Chris but I have thanks to George a report from the RLM regarding the operational evaluations made at 1.8, 1.9 and 1.98ata. It seems that 1.8 ata was not validated until late January 1945, and 1.98 test began at that moment. IIRC there were some sparkplug troubles...
Now, Butch says he's seen the RLM documents. We know that several German engines we're supposed to run at higher boost levels but were derated in service, for example the Fw190 was limited to 1.35 ata when it was supposed to be running 1.42 ata.
The Db605A in the 109G2 was supposed to run at 1.42ata. In June 1942, some time after the plane had entered service, the RLM issued an instruction banning 1.42 ata until futher notice. The instruction began:
A number of cases of breakdown in the DB 605 as a result of pistons burning through have occured. The following must therefore be observed:
The takeoff and emergency output with a boost pressure of 1.42ata and 2800 rpm may not at present be used.
Now, what do you think the 109G manual said prior to that? Max boost 1.42 ata? Yet it wasn't allowed to use that in service until June 43.
It's not like there isn't a precedent of a German engine not being safe to run at full power when it was newly introduced, is it?
"Almost certainly". Can you tell the details please? I certainly do know you don`t have any idea what a/c conditions those figures refer to.
And neither do you, which is the whole point Isegrim.
You have figures that we know very little about, yet you are using them as gospel.
Secondly: Would an engine configured for the C-3 (Hence the triangle) also run on conventional fuel such as the standard 87 oct?
It could, the DB 605D series were designed with fuel interchangebility in mind; however it would need to be reconfigured, which as far as I know from butch, was a complicated task enough not to be possible on unit level. In practice, that means if an engine was configured for C-3 (DB 605DC), it either run with C-3 or did not run at all. When configured to B-4 (DB 605DB) it could run at max boost with either B-4 and MW50, or with C-3 used alone. Because using high boost with low grade fuel would lead to premature detonation, the engine would run roughly, and soon fail at high powers; I am sure it would do no good to run it on low grade fuel at all, because of the different timing, spark plugs etc.
However the opposite was possible, running on higher grade when setting was for B-4; there are examples of DB 605As, that been designed for B-4, being refueled with C-3 (as nothing else was available at the base... hmmm) could takeoff and retur to base safely w/o problems. Of course there are no real gain from it, it`s like running your car on higher grade fuel than it needs.
This is the reason I believe the 109K4 was rarely able to match the figures in Isegrim's chart.
Isegrim's chart uses figures achieved at 2000 ps. 2000 ps required C3 and MW 50. B4 and MW 50 provided 1800or 1850 ps.
If configured for C3, the 109K4 would have to stay grounded if only B4 fuel was available. If configured for B4, the 109K4 could fly whatever type of fuel was available, but with "only" 1800/1850 ps.
Given the poor fuel state of the Luftwaffe, and the unpredictability of supplies, I don't believe the Luftwaffe could afford to gamble on the availability of C3, especially as the 190 units needed the C3.
It seems to me the military always settle for a bit less to ease the supply situation, and with the poor supply situation of the Luftwaffe late war they would have had to be crazy to configure a plane that could use c3 or b4 to use
only c3.
C3 is just aviation fuel and was by octane rating about 100/130 PN fuel and by aromatic content close to 100/150 PN. Comparable to the allied 100/150 octane fuel.
I think C3 was comparable, or even a bit better, than 100/130. But the 109 needed MW50 to reach the same sort of pressures without detonation as the Merlin on 100/150.
