And just another quick question - on the 205

[Anaxogoras]

That's a common myth: No production G-10 received a DB605AS as this would then be a G-14.

Not according to my source, 109 F, G & K Series by Prien and Rodeike.  What's your source?

[Masherbrum]

Not according to my source, 109 F, G & K Series by Prien and Rodeike.  What's your source?

Same as mine and I agree with what you posted.    Denniss, some G-10's had em.   

[Charge]

Which one do you think has more aerodynamic or cooling drag?

-C+

[Denniss]

Not according to my source, 109 F, G & K Series by Prien and Rodeike.  What's your source?

Old sources are often wrong or rel on these myths. As I said before: A G-10 with a DB 605AS would be a G-14/AS and not a G-10/AS as it's the engine that makes a G-10. The only possible G-10/AS designation may have been suitable for G-10 with very late war DB 605ASB or ASC engines as these engines are comparable to the DB 605DB used in the G-10 (with the ASC more comparable to the 605DC used in the K-4). I also told you this only applies to new-built aircraft. It's not impossible repaired G-10 airframes got a different engine type but I really don't now what their model designation was with a DB 605A or AS engine, probably G-10 designation overstamped to G-14.

A highly similar myth is that G-10 were all repaired/upgraded older airframes with a new engine.

[Anaxogoras]

Old sources are often wrong or rel on these myths. As I said before: A G-10 with a DB 605AS would be a G-14/AS and not a G-10/AS as it's the engine that makes a G-10. The only possible G-10/AS designation may have been suitable for G-10 with very late war DB 605ASB or ASC engines as these engines are comparable to the DB 605DB used in the G-10 (with the ASC more comparable to the 605DC used in the K-4). I also told you this only applies to new-built aircraft. It's not impossible repaired G-10 airframes got a different engine type but I really don't now what their model designation was with a DB 605A or AS engine, probably G-10 designation overstamped to G-14.

A highly similar myth is that G-10 were all repaired/upgraded older airframes with a new engine.

Source?

[Die Hard]

...as these engines are comparable to the DB 605DB used in the G-10 (with the ASC more comparable to the 605DC used in the K-4).

The 605DB and 605DC are the exact same engine, just tuned for two different fuel qualities. The 605DB used the B4 fuel, the 605DC used the C3 fuel. Changing which fuel the engine used took 30 minutes in the field.

[Boozeman]

While this discussion about the 109G and DB605 subvariants is all very intresting, it does not really add to the topic.

So, after reading the old thread, it seems that the 10/10 minute WEP was intended for MW50 boosted 605s, which to my knowledge our 109G2/6 does not have. So maybe that's wrong? Well, I dunno. However, since the 109F with the DB601E also has the same WEP characteristics, I suppose that this treatment of the DB605A is intentionally so. But in that case, the 205 should be no exception.

While there may be other issues with the 205 FM, the change to a 10/10 min WEP would be a quick fix compared to a complete FM overhaul and, I think, well worth it.   

[stroker71]

While this discussion about the 109G and DB605 subvariants is all very intresting, it does not really add to the topic.

So, after reading the old thread, it seems that the 10/10 minute WEP was intended for MW50 boosted 605s, which to my knowledge our 109G2/6 does not have. So maybe that's wrong? Well, I dunno. However, since the 109F with the DB601E also has the same WEP characteristics, I suppose that this treatment of the DB605A is intentionally so. But in that case, the 205 should be no exception.

While there may be other issues with the 205 FM, the change to a 10/10 min WEP would be a quick fix compared to a complete FM overhaul and, I think, well worth it.   

agreed!  Compared to other craft like it I think the overall FM is pretty good.  I never noticed the differance in WEP because I don't fly the 109's very much.  Good catch btw.

[Die Hard]

I never noticed the differance in WEP because I don't fly the 109's very much.  Good catch btw.

There probably is a good reason for it. In the February 1943 test of Italian and German fighters the report noted that the 205's climb performance was severely restricted due to the small radiator.


http://www.kurfurst.org/Tactical_trials/109G-4_Guidonia/109G-4_vergl_Estelle-Guidonia_de.html

[Boozeman]

There probably is a good reason for it. In the February 1943 test of Italian and German fighters the report noted that the 205's climb performance was severely restricted due to the small radiator.


http://www.kurfurst.org/Tactical_trials/109G-4_Guidonia/109G-4_vergl_Estelle-Guidonia_de.html

This was the 205N though, a non production prototype, not the 205V that we have.

[Die Hard]

This was the 205N though, a non production prototype, not the 205V that we have.

The N had a redesigned wing and forward fuselage. The engine and cooling system was the same.

[Anaxogoras]

Wow, so we finally have a working hypothesis: Less efficient cooling reduces WEP and its duration.

[Boozeman]

The N had a redesigned wing and forward fuselage. The engine and cooling system was the same.

And even more stuff than that. For instance, the N also had an engine mounted cannon, the V did not. This can also affect the engine cooling, but has in fact zero relevance to the 205 modeled in AH. Also, what makes you so sure that the cooling system was exactly the same? Maybe this only came into effect due to the low speed high power condition during the climb? Maybe its perfectly fine at higher speeds?

I am not doubting that there were differences in cooling performance between different planes in real life for lots of reasons and also different flying conditions. However, and I think for a good reason (most likely the lack of hard data), this "layer" is not really modeled in AH, so it it should not be applied to certain planes, and then not to the others as well.

Lets take the RR Merlin for example: No matter which Spitfire, which Hurricane, or the Mossie - all have exactly the same WEP characteristics, but the chances that all these had equally efficient cooling systems under all flight conditions in real life are almost zero. Heck, even the Spit 14 with the Griffon does have the same WEP...which is a completely different engine...

   

[Die Hard]

And even more stuff than that. For instance, the N also had an engine mounted cannon, the V did not. This can also affect the engine cooling, but has in fact zero relevance to the 205 modeled in AH. Also, what makes you so sure that the cooling system was exactly the same?

Because it was. Same engine, same radiator. Both the 205 V and the N were up-engined 202's, but the N was a more radical redesign incorporating a new wing and forward fuselage (which allowed an engine cannon). For production reasons the simpler V was chosen (required less modification of the 202 production line).

Maybe this only came into effect due to the low speed high power condition during the climb? Maybe its perfectly fine at higher speeds?

All cooling deficiencies are most pronounced during climb, since the engine is at full power and the airspeed is slow. However, that is a good measure of the available cooling reserve at high speed. You must understand that if these planes has sufficient cooling they could in theory operate at full power indefinitely, but they didn't. If one plane has better cooling during climb it also has more cooling reserve at high speed. However, this is all academic since Aces High is far too inaccurate in engine modelling. It is too generic to accurately model realistic engine management and cooling, so all planes have a generic amount of WEP. The 109 series is no exception, and has in my opinion been given a generous amount of generic WEP. So has some of the allied planes like the water-injected Jugs and F4U's which carried a very limited (5 minutes if I remember correctly) supply of water. When the water runs out their WEP also runs out permanently, but this is beyond the level of detail modelled in Aces High.

If we take a 1943 109G with a DB 605A as an example: In real life it had two WEP settings. One 3 minute emergency power, and one 30 minute climb and combat power. In AH this is generalized into a generic 10 minute WEP (at the full Emergency setting). I think this is very generous. The 109F had three "WEP" settings, but maximum power was only available for one minute. The only 109's that had full power available for 10 minutes were the late-war MW-50 equipped versions.

So you see, we can debate the various cooling systems of different aircraft to our hearts' content, but given the lack of detail in AH's engine modelling it is all academic.

[gatt]

The cooling problem of the Guidonia C.205 was a problem of *that* aircraft. We never found any document about cooling problems of the license built DB605A engines.

Here are the power curves from the official Fiat DB605A manual:



However, all the official test documents we found report 1.3ata and 2.600rpm as max rate allowed. We dont know if, after 1943 summer, C.205 pilots were allowed to run their engines at 1.42ata and 2.800rpm.

Only the G.55 flight manual (1944) shows the max rate:



Actually, there is no reason why the DB605A of the C.205 should run differently from the ones mounted on the 109G-2 and G-6 (early). And yes the C.205 FM and graphics are maybe 6-8 years old. Thats why 5 years ago there were 2 big squadrons with some 30 italian players in AH and now there are maybe two or three of them ...