I send the PM.


;)

Many Thanks

This explains many things .

After reading both articles I have to say that the Kurfürst article seems to be way better researched. As a German native I can definitely say that the Kurfürst translations are way more accurate.

Err... I was under the impression from multiple, varied sources that the early Spits generally *were* inferior to their chronological counterpart 109's in a number of ways.

As I understand it, Spits always had better turn rates across the board and the 109's were never able to take the lead. The early Merlins were inferior and had fuel starvation problems in negative G situations, there was a band-aid solution that partially worked until several years later it was fixed. All but the earliest 109's had the Kommandogerat device which automated pitch and mixture, most also had automated radiator controls. Later Spits had more automation that worked, and as the war went on they had better armament, the later Merlins and Griffons were on par with or superior to their German counterparts, and the performance gap was finally closed.

Well its not so much inferior, its more that its effete and girly. The Spitfire is far too pretty and only flown by nancy boys and big girls blouses. The Hurri on the other hand, like the 109, is a mans airplane 8-)

The AM could use B-4 as well with maximum power (1.7ata), a G-14 MW 50 manual mentions that while C-3 is preferred as normal fuel, its possible to use B-4 in emergency with MW-50. It was more risky than using straight C-3 and MW 50 combo, since any failure in the MW system meant that the engine would immidiately start knocking and self destroy in short order. B-4 alone could not take the compression at 1.7 ata without detonation, while C-3 could. I have not seen a similar manual for the ASM but its a rather safe bet it worked the same, given the minimal difference (supercharger) between the AM and ASM.

IMHO the corresponding Marks of the Spitfire were more or less on par with the 109s, ie. Mark I vs 109E, Mark IX vs 109G, Mark XIV vs 109K - the only exception of the Mark V that was a bit inferior to the 109F from the start, and later Mark IX (1943 with the Merlin 66) that took a lead on the contemporary 109G-6.

The problem with not so much with development, but deployment. Even though there were as good Marks of the Spitfire at the same time, they were never entering service as quickly as the newest 109s. Mark Is may have been as good as 109Es, the difference was that all 109s were Emils in 1939/40, while most of the RAF still had Hurricanes and only a handful of Spitfires in comparisons. The Mark IX may have been about as good as the 109F/G in 1942/43, but again the difference was that while all 109 units had 109Gs, most of the RAF Spitfire Squadrons were still flying Mark Vs - even at the start of 1944 the Mark V was the most common Spitfire, just about to be replaced by the Mark Niners but the LW was moving to the next phase of MW boosted 109s and/or AS engines; the Mark XIV may have been as good as the 109K, but it mattered little given that 90% of the RAF Spitfire Squadrons were still flying Mark IXs, which were a bit overhwhelmed in performance by late 1944.

A bit more was added to that subject of 1.98ata 109K (and G-10s! people always seem to forget the G-10 had the same engine and ratings!) here: http://www.kurfurst.org/Engine/Boost...arance198.html

There are some new developments in the matter about the role of II/JG 11, but essentially the facts remain the same.

As to the question at hand - cooling effects of MW-50 - it can be stated with definite certainty that overheat of coolant should not be a problem at all. We have German datasheets of DB 605A and DB 605AM showing the max. heat transfer data of the engine (how much heat the engine generate to be carried away - max. abzufahrende Waermemenge in German table). The data shows that the 605AM, with MW-50 and operating at max boost, ie. 1.7ata / 1800 HP actually makes less heat than the MW-less DB 605A at 1.3ata / 1310 HP. I don't have that paper on my site yet, only extracts, but I think it was referred above.

Now the 109G's cooling system was effective enough to keep the temperatures down well below safe limits at around 85 Celsius in full power climbs, ei. 1.3ata / 1310 HP, when airflow through the radiators is minimum (the DB 605 manual notes the engine can tolerate around 110 Celsius coolant for 10 minutes). http://www.kurfurst.org/Performance_...es/blatt10.jpg

As noted above with MW 50 the coolant system had to cope with even less heat. Add to that that high altitude 109s (G-6/AS, G-14/AS, G-10, K-4) had larger sized oil/coolant radiators fitted. See http://www.kurfurst.org/Performance_...u4_am-asm.html

1.) DB 605 AM i = 1,685 mit MW-50
G = 3515 kg
Wasserkühler Fk = 33,6 dm2
Ölkühler Fk = 6,5 dm2
Luftschraube 3 flg. vorhanden als 9-12078

2.) DB 605 ASM i = 1,685 mit MW-50
G = 3550 kg
Wasserkühler Fk = 42.0 dm2
Ölkühler Fk = 8,5 dm2
Luftschraube 3 flg. vorhanden als 9-12159

and http://www.kurfurst.org/Performance_...t_109K_EN.html for 109K

Radiators : Coolant radiators Fk = 36 dm2
Oil cooler Fk = 8.5 "

This seems to be a general weakness in the Il-2 engine - coolant overheating was generally overdone, probably to impose some limit on using max. power or to simulate 'engine wear'. At least I can confirm that for 109s, which as per historical data very unlikely to ever reach maximum limits without closing the radiators completely or something similiarly stupid. The worst thing that can happen is that the coolant radiator flaps open.

I dare to say that it was a common thing that outdated planes were still in service although they had already been succeeded by newer versions. According to Eric Membeek's JG 5 chronicles the Jagdgruppen of JG 5 which were operating from Kirkennes/Petsamo used the 109 T in 1941 (which is basicially an Emil). As far as I remember (don't have the book right here) they still had Ts in 1942 and were recieving their first F2 and F4s. In Il-2 you are flying G2s by that time. Dunno when they got their first Gs, prolly in 1943.
And while this Gruppe still had Ts and Fs their neighbour-Gruppe in Stavanger got the 190A in spring/summer of 1942.
I guess that the Luftwaffe had some kind of priority list for upgrades. Those units at the channel (JG 26) were probably on top while the parts of JG5 at the edge of the theatre were down on the bottom.

On the other hand, when the RAF sent their 151st wing to support the VVS at the Murmansk theatre, this wing was equiped with Hurricanes. So in winter '41/42 it was 109Es vs. Hurricanes (once again).
I don't know about the 2nd half of the war and the Reichsverteidigung. I could imagine that the Luftwaffe had more recent planes in their units (cause their losses increased and the old ones were "outphased" this way).

Very informative, Kurfürst!

Let's hope TD will rectify the MW-50 in the incoming patch.