# LA-9 vs FW-190A8/9



## Bug_racer (Apr 7, 2010)

Looking at these two aircraft you can see the similarities between the silhouete of the planes . How much of the LA-9 design was copied from the fw-190 and how would they compare in flight with each other had the war lasted a little longer ?


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## gumbyk (Apr 7, 2010)

Sorry, I can't see any more similarity beyween these two aircraft, and any other two radial engined, low-winged fighters of the time:










but, from the website of the company that performed the restoration:


> Since then Ray has made his first ( and successive ) flights and has stated that he thinks it out performs a Bearcat or a Sea Fury.


 August 2003

Not sure how htis would compare with the FW-190 though, but it would give some indication of the climb performance from a real-world experience.


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## davebender (Apr 8, 2010)

Lavochkin La-9 - Wikipedia, the free encyclopedia
Introduced August 1946 

Focke-Wulf Fw 190 - Wikipedia, the free encyclopedia
Assuming Germany still exists during 1946 the Fw-190A9 should be powered by the 2,367 hp BMW 801F engine.

Personally I consider it doubtful the Fw-190A series would remain in production once the Ta-152 enters mass production. The Fw-190F and Fw-190G ground attack variants would be the only radial engine Focke-Wulfs during 1946.


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## timshatz (Apr 8, 2010)

gumbyk said:


> Sorry, I can't see any more similarity beyween these two aircraft, and any other two radial engined, low-winged fighters of the time:
> .



Agreed. The late war radial engined aircraft all tended towards the same design, dictated by experience of designing and engine power increases. Probably had similar dimensions.


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## tomo pauk (Apr 8, 2010)

Bug_racer said:


> Looking at these two aircraft you can see the similarities between the silhouete of the planes . How much of the LA-9 design was copied from the fw-190 and how would they compare in flight with each other had the war lasted a little longer ?



La-9 was mere development of La-7, the main difference being it was full metal plane (wings and armament got changed, obviously).
The comparison of planes divided by 2 years (in WW2 era) is pretty vague anyway.


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## vanir (Apr 8, 2010)

Agree with general consensus. I think to get at the roots of La-9 design you head to the original La-5 which did coincidentally just begin to enter service when the first Fw-190A were being service evaluated on the Eastern Front in small numbers, the introduction of either is the same timeframe and yet development of the Fw-190A goes back a little further.

I think however it is most likely the fact they were both 14-cyl radial fighters intended for the front line role is just coincidental, the same way the Germany and Britain both decided on developing high horsepower inline engines during the mid-thirties. Just a period thing, and recognition aero technologies are generally on a world scale rather than by individual nation (except for specific innovations usually in equipment or modification).

Also while there are cases of a specific fighter model being purposely designed around a specific engine type, what generally happens is airframe design and aero engine fitment are two completely independent projects. The La-5/7/9 series airframe began life as the LaGG-1/3 inline engine fighter roughly similar to a British Hurricane performance wise.

Two high performance radial engines were under codevelopment in Russia in 1941 (the other one was a 2000hp engine to the M-82's 1500hp, the M-84 iirc but I think it had reliability problems), these had an entirely new prototype the I-185 built around them which had spectacular performance but it never entered production. I assume to speed things up the succeeding engine type was fitted to the LaGG-3 to produce the La-5. Then aircraft in continuing production became increasingly modified/refined as necessary, following typical WW2 Russian aero manufacturing procedure.

So I don't think there's any way to compare the La-9 with the Fw-190A-9 except to compare two completely independent radial engine fighters.


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## Bug_racer (Apr 8, 2010)

So you think the la-9 had no influence at all from the fw-190 ? Ok fair enough . But how would they perform against each other ? Probably be more of a factor of pilots than planes ?


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## Knegel (Apr 9, 2010)

Hi,

the La9 is more a La7 with square wingtips and the La7 base on the La5 and this on the La3.

I doubt there is a real influence of the FW190A appart from the idea to use a radial engine for the La5, maybe.

The La9 would outperform the 190A as dofighter, same like the La7 did, due to the much smaler weight with similar power. 

I have no idea where the weight of the FW190 came from, but i guess it was more tough regarding damages, so it would probably be the better attacker.

Though, the 4 x 20mm in the nose of the La9 is a real step forward to the 2x20mm of the typical La7, so regarding the guns the La9 proabably wins.

The FW190A is imho the most overvalued fighter in WWII, only cause it had so much success within a rather unimportant year, vs SpitV´s, it get praised like mad. 

The airframe was for sure very good, but what is a fighter worth, without a fitting and good working engine??

Look to the Wirlwind, the He177, the P40´s, all good airframes with problematic or bad engines. 
And look to the different between SpitVc and SpitIXc or P51A and P51B only due to the engine.

The heavy FW190 would have needed a 2000HP engine in early 1943 or a much more streamlined and light airframe + DB605A and that with C3 fuel and later with MW50 + C3 fuel.

Like it was it was outclassed as fighter latest late in 1943, when the Merlin66, the La5, the P47C and Yak9´s was available in bigger numbers. From that moment onward the FW190A was more or less derated to an Attacker, while the 109F and G still could go into a dogfight.

The FW190A initially was like the P40E in the pacific, but then all, not just a few, enemy planes turned to be Ki61´s and Ki44´s, which was able to do almost all as good.

Greetings,

Knegel


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## bada (Apr 9, 2010)

Knegel said:


> The La9 would outperform the 190A as dofighter, same like the La7 did, due to the much smaler weight with similar power.



the LA7 didn't outperformed the A8 , at low altitude (under3000m)yes, not at up high.But the La7 still couldn't catch the old A5/6 Jabo with C3 injection under 1000m



Knegel said:


> The FW190A is imho the most overvalued fighter in WWII, only cause it had so much success within a rather unimportant year, vs SpitV´s, it get praised like mad.



Not only against the spit5, also against the spit9 m61.From 6500up, the spit whas superior but under this altitude, the planes clearly equivalent to eachother, just like the english test shown. Not bad for a plane that was in service more than a year against a whole new model built expressly to beat it,no?
Also, not forgetting the A4 send from dec42 on the eastern front, find me one bad comment from a pilot of the JG54 about the fw190



Knegel said:


> The airframe was for sure very good, but what is a fighter worth, without a fitting and good working engine??



And what was the pb with the 801D2? highr power controled by an mechanical computer, leaving the pilot do his job instead of constantly moving throttles and pushing buttons.Easy to access, well armored.




Knegel said:


> The heavy FW190 would have needed a 2000HP engine in early 1943 or a much more streamlined and light airframe + DB605A and that with C3 fuel and later with MW50 + C3 fuel.



And why?1820ps is enough for a plane of 4000kg weight fully loaded. As about it's streamline, the 190 was more clean than spits, even with a bigger front area (a radial, it's big), it's total cx was still lower than the spits.



Knegel said:


> Like it was it was outclassed as fighter latest late in 1943, when the Merlin66, the La5, the P47C and Yak9´s was available in bigger numbers. From that moment onward the FW190A was more or less derated to an Attacker, while the 109F and G still could go into a dogfight..



aah? and in what could the M66 be better than an A5 with new modified engine? (first half 43, 801D2 received several parts of the 801F allowing higher pressure thus output.for all further production)
What tells you it was outclassed?



Knegel said:


> The FW190A initially was like the P40E in the pacific, but then all, not just a few, enemy planes turned to be Ki61´s and Ki44´s, which was able to do almost all as good.



In difference to the P40, the 190A was always modified and upgraded through the years, engine included.
If you compare an A2 from41 to an A8 from45, you'll see the same power/weight ratio. the plane keeping it's easy flying caracteristics.


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## Knegel (Apr 9, 2010)

bada said:


> the LA7 didn't outperformed the A8 , at low altitude (under3000m)yes, not at up high.But the La7 still couldn't catch the old A5/6 Jabo with C3 injection under 1000m



I wrote "as a fighter", not as a Jabo. The C3 injection got intoduced for the Figher only in mid 1944!!
Until then the 190´s was clearly outperformed for a year. Only below 1000m they was at best even.
In late 1943 the A5 and A6 wasnt old, they was the standard FW190A at this time. And the La7 with 1850PS was as fast as the FW190F or G with 2050 to 2100 PS. So the Jabos also couldnt get away. If they made one slight turn, they was lost, cause the extreme higher weight(almost 1000kg) was a real handycap.



bada said:


> Not only against the spit5, also against the spit9 m61.From 6500up, the spit whas superior but under this altitude, the planes clearly equivalent to eachother, just like the english test shown. Not bad for a plane that was in service more than a year against a whole new model built expressly to beat it,no?
> Also, not forgetting the A4 send from dec42 on the eastern front, find me one bad comment from a pilot of the JG54 about the fw190


The SpitIXc wasnt a whole new model, it was a SpitVc with Merlin61, while the Merlin61 dont got used that often as i wrote above. It got replaced rather fast with the Merlin66.
There was just around 900 Merlin61 powered Spitfires, then the Merlin66 got introduced. 
I actually doubt that the Spitfire had a higher drag than the FW190A. Spitfires with 1800 HP at sea level was as fast as the 190´s. As higher we get as more the extreme wingload of the FW turned to be a handycap. The Merlin66 produced 1710HP, the BMW801D-2 1750PS , what is very similar, while the Spitfire with Merlin 66 had clear advantages from 1000m upward and 1000m is nothing and its not the hight where the combat took place in general. 
A fighter should someohow be able to fight with enemy fighters, the 190A at best could run from late 1943 onward.

At the eastern fron the 109G was at least as good, without the need of super fuel. The 109 was the ace maker in the east. Many, not only germans, got clos to or more than 100 kills in 109´s, only a few got that many in 190´s.



bada said:


> And what was the pb with the 801D2? highr power controled by an mechanical computer, leaving the pilot do his job instead of constantly moving throttles and pushing buttons.Easy to access, well armored.


The problem was that its performence was poor with combat climb(1750/1800PS was WEP) specialy above 1000m and then again above 5000m, while the combat in the west tool place mainly above 5000m and in the east there was the La5 and La7 with a better performence in low alt. 



bada said:


> And why?1820ps is enough for a plane of 4000kg weight fully loaded. As about it's streamline, the 190 was more clean than spits, even with a bigger front area (a radial, it's big), it's total cx was still lower than the spits.



1750/1800PS(depending to when) would have been nice in 3000-5000m, but just 1820PS peak in 800m and then fast decreasing to less than 1500PS in 2500m is poor in late 1943. And at that time the plane (190A5/6) already had a weight of 4100-4200kg. 
Ops and that was WEP, just 1600PS comabt/climb iin 800m and then below 1350PS above 2500m is extreme poor.

If you compare that to the DB605A combat climb + 109G6 airframe(3150kg clean, 3250kg with gunpods), which had around 1420PS in 2000m and only sllowly decreasing to rated alt(5800m) + a not to smal exhaust thrust, what was badly missing for the BMW801 due to bad exhausts(later that got corrected for the FW190A9, but to late.

The FW190A was a real low level fighter, goos in altitudes below 1500m, above that the climb turned to be horrible and the speed was just ok, but not anymore outstanding like vs the SpitV and the performence(speed/climb) of the FW190A mainly decreased till mid 1944, when the extra boost due to C3 injection got introduced, but at that time it was to late again, cause the enemy by then already had 150 octan fuel.

So as Jabo it was good, as fighter rather poor(late 1943 oward), specialy in the west. 




bada said:


> aah? and in what could the M66 be better than an A5 with new modified engine? (first half 43, 801D2 received several parts of the 801F allowing higher pressure thus output.for all further production)
> What tells you it was outclassed?the spits.


The datasheets, the (german)pilot comments. 
The Spitfire with merlin66 only was less good below 1000m alt, above that it did outclimb the 190A5 by 200-400m per in, it could turn circles around the 190, it was as fast as the 190. 



bada said:


> In difference to the P40, the 190A was always modified and upgraded through the years, engine included.
> If you compare an A2 from41 to an A8 from45, you'll see the same power/weight ratio. the plane keeping it's easy flying caracteristics.


The P40 got way more modification than the FW190A. They started with just 1000HP and ended with 1550. The A8 for sure dont had the same flight characteristics like the A2. Even the clean A8 had 400kg more weight and the power above rated alt still was the same. A such the service ceilling of the A8 was good below that of the A2. 
Btw, initially the BMW801D-2 was derated to 1750PS, later it could use the full 1800PS(sea level), the different was marginal.
The problem was, that the engine was poor in the altitudes where combat took place in the west and that the Russians had equal engines for low alt with a more light airframe. 

The 190 airframe, slimmed down to use the DB605A would have had a weight of maybe 3300kg and would have been nice streamlined. Then the DB605A would have had the C3 fuel to produce 1475PS sea level as combat/climb. That plane would have been fast, manouverable, good climbing and good at high alt. With the BMW801 the 109´s lost the needed high octan fuel, so the DB605A lost in comparison to the merlins and so germany in late 1943/ early 44 only had a down rated DB605 and a still to bad uprated BMW801 vs Merlin powered planes that could use higher and higher presures due to better fuel.

Out of this the myth of a obsolete 109G got born, but a plane is only as good as its engine. 

Greetings,

Knegel


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## Vincenzo (Apr 9, 2010)

La 7 it's not of mid '44 like C-3 on 190 fighter? or yes so it's right compare it, la 7 was not a late '43 fighter.
Spitfire IX was a uncommon RAF fighter until spring '44.
it's true that 190 A5 A6 was the common 190 in late '43 but Spitfire V was the common spitfire in late '43


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## davebender (Apr 9, 2010)

Dr. Tank wanted the DB603 engine for the Fw-190. In my opinion that's what should have happened. 

Why did RLM cut funding for DB603 engine development during 1937? One of their worst decisions. The DB603 engine could have powered the Fw-190 fighter and Do-217 bomber from 1941 onward.


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## Knegel (Apr 9, 2010)

Hi,

the 1st SpitIXc´s arrived in mid 1942(Merlin61), 1943 was the year of the Merlin61 and Merlin63 SpitIXc, with the ongoing year they used the SpitVc mainly with a upgraded low level engine with an outstanding climb performence and often with clipped wings. Already in mid 1943 even the SpitVIII arrived.

The fall of 1943 the Merlin66 powered Spits arrived and by the end of the year they was alredy wide spreaded.

In early 1943 the Luftwaffe also mainly had 190A3´s and A4´s(build till march 1943). Sure there was still some Merlin45 powered SpitVB´s and SpitVc´s around, but the SpitIXc + VIII (Merlin61/63/66/70) and also the was very common late in 1943 and appart from very low level and the Merlin61 powered planes, they all outclassed the FW190A5/6 as fighter(not as attacker or jabo, just as fighter). 

Greetings,

Knegel


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## Knegel (Apr 9, 2010)

Ops, i forgot:
Yes, the La7 was came in spring 1944, but the late 1943 La5FN´s wasnt much different anyway. The La7 mainly had a better cooling system, allowing the pilot to climb with WEP and to use it for 10 minutes in level flight, while the La5FN was of same nature like the 190A5/6, only short endurance WEP(1850PS).

Hi davebender,

regarding the DB603 i agree, this engine with C3 fuel and later even MW50 and 3 stage supercharger would have been a solution. That engine in 1942 in the FW190 and the 109 would have been fully replaced.


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## Shortround6 (Apr 9, 2010)

vanir said:


> Also while there are cases of a specific fighter model being purposely designed around a specific engine type, what generally happens is airframe design and aero engine fitment are two completely independent projects. The La-5/7/9 series airframe began life as the LaGG-1/3 inline engine fighter roughly similar to a British Hurricane performance wise.


While a number of fighters were designed to take different engines from the start it was more common to design fighters to take one type (air cooled radial vrs liquid cooled engine) of engine. While some designs were able to switch at a later date other designs were not. Some attempted conversions had trouble with airflow break down in the transition from the fat radial to the skinny fuselage of the V-12 fighter and higher than expected drag and some even had problems with turbulent air flow over the tail surfaces. 


vanir said:


> Two high performance radial engines were under codevelopment in Russia in 1941 (the other one was a 2000hp engine to the M-82's 1500hp, the M-84 iirc but I think it had reliability problems), these had an entirely new prototype the I-185 built around them which had spectacular performance but it never entered production. I assume to speed things up the succeeding engine type was fitted to the LaGG-3 to produce the La-5. Then aircraft in continuing production became increasingly modified/refined as necessary, following typical WW2 Russian aero manufacturing procedure.


Both the M-80 and the higher powered M-70 started development in 1937-38. The M-80 eventually became the M-82/ASh-82 while the M-70 finally turned into the ASh-73that powered the TU-4 bomber. The M-71 that powered the I-185 was a beast of an engine, an 18 cylinder 3,643cu in (59.7 litres) device. Basically two wright 1820s ( or Russian equivalents )on a common crank. This can explain the high performance but using an under developed Russian version of a Wright R-3360 can also explain the lack of production, along with factory evacuations. Given the 3-6 year development times of engines and the 2-4 year development tomes of airframes I think it is much more parallel development than anybody coping anybody else.


vanir said:


> So I don't think there's any way to compare the La-9 with the Fw-190A-9 except to compare two completely independent radial engine fighters.



I agree.


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## tomo pauk (Apr 9, 2010)

Knegel said:


> ...
> The 190 airframe, slimmed down to use the DB605A would have had a weight of maybe 3300kg and would have been nice streamlined. Then the DB605A would have had the C3 fuel to produce 1475PS sea level as combat/climb. That plane would have been fast, manouverable, good climbing and good at high alt. With the BMW801 the 109´s lost the needed high octan fuel, so the DB605A lost in comparison to the merlins and so germany in late 1943/ early 44 only had a down rated DB605 and a still to bad uprated BMW801 vs Merlin powered planes that could use higher and higher presures due to better fuel.
> ...



Have you checked that kind of Fw-190 in my 'Re-engined planes' thread?


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## Knegel (Apr 9, 2010)

Nope, i will have a look, if i find it.


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## vanir (Apr 9, 2010)

> Both the M-80 and the higher powered M-70 started development in 1937-38. The M-80 eventually became the M-82/ASh-82 while the M-70 finally turned into the ASh-73that powered the TU-4 bomber. The M-71 that powered the I-185 was a beast of an engine, an 18 cylinder 3,643cu in (59.7 litres) device. Basically two wright 1820s ( or Russian equivalents )on a common crank. This can explain the high performance but using an under developed Russian version of a Wright R-3360 can also explain the lack of production, along with factory evacuations. Given the 3-6 year development times of engines and the 2-4 year development tomes of airframes I think it is much more parallel development than anybody coping anybody else.



Thanks for the correction Shortround, great info! (I had read about it only in passing and memory fails, but I didn't know anything so detailed in the first place, much appreciated)



> Then the DB605A would have had the C3 fuel to produce 1475PS sea level as combat/climb.



Respectfully I don't think it was so easy. The 605A was already having problems with piston burn and overheating/seal integrity using B4 fuel, the original modification of basically upsizing the 601 internally for more power is an old engineering shortcut and the problems with it were those experienced with the 605 series until the D was developed with better oiling under the pistons and journals throughout (it was a new block from the 605A).

You needed a 605D to use C3 and 1550PS, which weren't available until ~September 44 and by then it needed sonder WEP anyway to remain competitive in a tight spot. For most of 1943 all you're going to see out of a 605A is about 1320PS at sea level and 1250PS at the rated altitude and even this would be safer for ten-twenty min rather than the 30min normal rating.

The really great thing about the 605A in '43 was a pretty effortless output particularly in the cruise/climb regimes. It could take a great load up very high pretty smartly and always entered combat at a good speed even out of the cruise. It handled very well at airspeeds of 300-700km/h, with a predictable stall and good speed characterstics at 6-7000m.

Flat out though, even with C3 and MW50 in Feb44 you're looking at 1500PS under sondernot at the combat height using a DB603 supercharger fitment (AS motor) and the regular 605A supercharger had its rated altitude reduced to 4000m, so only had average late 43 performance at the combat height (1250PS at ~6000m).
And here's the thing, without the improved D block and oiling you only had 1-2min of sondernot to work with, max. I saw a report once saying it shouldn't really be used at all unless the pilot is in imminent danger of being shot down.

Really in terms of combat rating you're talking about 1250PS for the 605A until late 44 where it becomes 1600PS for 5-10min and then about 1300PS normally for extended periods at the combat altitude in the D block.

Also there is no evidence the 605DC or ASC were ever actually fitted to Messerschmitt in service, all evidence points to DB or ASB engines only (1850PS max sea level up to around 2000m).
I'm still trying to figure out the exact differences in engineering terms between the ASB/C to the DB/C, the designation suggests a bottom end change to the AS motor where the D series is a new block, perhaps production ease was the consideration for it, but the ASB/C has better cruise output than the D series (so it would have better range and loadbearing in normal flight) but otherwise maximum outputs are identical. In any case the ASB/C are a 1945 engine.


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## Knegel (Apr 10, 2010)

vanir said:


> Thanks for the correction Shortround, great info! (I had read about it only in passing and memory fails, but I didn't know anything so detailed in the first place, much appreciated)
> 
> 
> 
> ...



The DB605A was alloed to use WEP from late 1943 onward, the limitation was, like in most cases, the octan related problems(overheat due to detonations). With C3 fuel WEP wpuld have been combat climb.
If there would have been another WEP stage i cant say, but WEP as combat climb would have been a huge step forward for the 109´s in late 1943 early 44.

Its possible that even the DB601E could have been upgraded by this.

Greetings,

Knegel


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## riacrato (Apr 10, 2010)

It's funny how the BMW801 always gets panned on this forum, yet I read mostly praise for it in interviews and publications(after the intitial overheating problems were fixed that is). There are even pilots who very much dislike the Jumo engined Fw 190s compared to the BMW801, even though from the desktop point of view it was much superior. It's not all in the statistics.


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## Knegel (Apr 10, 2010)

riacrato said:


> It's funny how the BMW801 always gets panned on this forum, yet I read mostly praise for it in interviews and publications(after the intitial overheating problems were fixed that is). There are even pilots who very much dislike the Jumo engined Fw 190s compared to the BMW801, even though from the desktop point of view it was much superior. It's not all in the statistics.



If a Pilot disliked the Jumo, it was the early one, without MW50 or a other boost, with just 1750PS. The very early D9 was not better below 5500m than the A8 at same time, only above the D9 was better.

I never saw praise of the BMW801, appart from its initial time, due to its extreme power advantage over the SpitV´s Merlin.
What got praised was the "Komandogerät" to provide a simple controll, but thats something different. 

As soon as the aircombat shifted to height above 6500m(due to the 4 Mots) and as soon as the La5FN was available in high numbers, the BMW801 wasnt strong enough anymore to let the heavy 190A be a good fighter. From that time on, the 190A´s only could run away. Only when a allied pilot was stupid enough to follow the 190 below 1500m the odds got more even, but due to the poor climb ration, even then it would have been very difficult to gain and keep a advanced position. 
The 190A9 just came one year to late, same like the DB605D. 

Greetings,

Knegel


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## riacrato (Apr 10, 2010)

From what I read in JG54 diaries barely anyone knew there was a LA-5FN nor was it felt as such a major step up combat wise. Fw 190s still could bounce on them with ease.

And about the Jumo vs BMW: That is your speculation. The interviews I read were from post-war and didn't mention whether or not the Jumo in question was with MW50 or not.


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## Knegel (Apr 10, 2010)

The JG4 was located in an not that important area, also the FAF seldom saw La5´s up there, but on the main front areas it saw plenty of action. Even the Brewster Buffalow was successfull there.

You even can bounce on someone with a stone, but thats not what i would call fighter combat. 
The 190A was not that much outperformed in the east like in the west, cause the VVS particular did fly some bad outdated planes, still it had way better oponents in high numbers since mid/late 1943. 

Btw, with the Jumo, the plane got way to heavy, even with only two cannons it was as heavy as the clean 190A8 with 4 cannons, still it was much faster in all altitudes and specialy above 5500m.

Imho the 190 airframe never got a good engine. The BMW was poor in high alt, the Jumo made the plane heavy, what wasnt good with the smal wings. As result they had to reconstruct it(Ta152C and H), cause it clearly missed slowspeed turn manouverability.


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## riacrato (Apr 10, 2010)

Being the second most successful wing in history I discard your negative comments on JG*5*4 thank you. And there were plenty of the latest Russian types encountered. That the Fw 190 was so popular with this wing is even more astonishing since it entered the scenario only when it began to lose its definite superiority over the contemporaries (i. e. early 1943).

The weight difference between late Anton and Dora variants is insignificant. My data shows the Dora as slightly lighter when loaded than the Anton, I don't know what you're getting at.

And if you call boom and zoom not fighter combat than I'm very sorry for you that east, west and Pacific alike this was the preferred type of combat for anyone who wanted to stay alive


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## Vincenzo (Apr 10, 2010)

Knegel said:


> Hi,
> 
> the 1st SpitIXc´s arrived in mid 1942(Merlin61), 1943 was the year of the Merlin61 and Merlin63 SpitIXc, with the ongoing year they used the SpitVc mainly with a upgraded low level engine with an outstanding climb performence and often with clipped wings. Already in mid 1943 even the SpitVIII arrived.
> 
> ...




in the july of '43 RAF in british islands has 7 Spit IX squadrons, 8 Spit IX&V squadrons and 24 Spit V squadrons, 2 squadrons with Spit XII and 4 high altitude squadrons with Spit V,VI,VII and an other 40 squadrons with not Spit fighter. the 1st jan '44 the most common was ever Spit V but now IX was near, squadrons 24 and 20. 
the first july the most common 190, in fighter unit, was A-5 (the A-3 was less of 1/12 of all anton), the 1st january '43 the A-4 (the A-3 was around 1/5 of all anton)


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## vanir (Apr 10, 2010)

> The DB605A was alloed to use WEP from late 1943 onward, the limitation was, like in most cases, the octan related problems(overheat due to detonations). With C3 fuel WEP wpuld have been combat climb.
> If there would have been another WEP stage i cant say, but WEP as combat climb would have been a huge step forward for the 109´s in late 1943 early 44.



Okay I'll try again. The problem was overheating which caused predetonation, it wasn't the other way around so octane wasn't a fix for the problems with the 605A. Here's what happened, the motor ran hot on B4 at more than 1.35ata and it then did two things, it predetonated under loading and it opened up the seals and flamed. C3 cannot help this.
In order to put C3 into a 605A and up the boost you need to use MW50, so you might as well raise the boost all the way to 1.7ata which was done when MW50 was fitted from Feb44 and C3 could finally be used in the 605A.

Otherwise to use C3 just on its own you needed the D series block or else you're just going to flame the engine even if you can sort out the pinging due to higher running temperature (not the other way around). Using just C3 without MW50 you can get 1550PS out of the 605 (demonstrated), but it has to be the D block because it runs too hot for the A block.



> Its possible that even the DB601E could have been upgraded by this.



The 601N used C2/3 for extra performance but the 601E was a further refinement and switched back to B4. According to German sources B4 was definitely the preferred fuel type because the additives used to make C3 (C2 was passing out of availability) lowered the engine life dramatically and raised maintenance. It hurt the valve gear, ran through plugs quickly and generally wasn't the better option.
In any case the 601E gave better performance than the 601N with a better rated altitude and better WEP, mostly due to redesign of the combustion chamber and piston crowns which were quite advanced, and carefully tuned valve timing and heads redesign. Using C3 would basically give roughly the same performance but drop the rated altitude with the higher compression by up to a thousand metres, which is undesirable. You could install a larger supercharger casing to compensate, but this would reduce low altitude performance, which was undesirable. The 601E was a pretty damn good engine on B4 and about the limit of 601 development, no need to mess with it.

The smart option was a new engine, anything else immediately available was underpowered, inappropriate or still in development and the 605 was a good shortcut to squeeze some more life out of the 109. Anyway I think by this time it was clear the 190 was the new kid on the block.


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## Kurfürst (Apr 10, 2010)

vanir said:


> Respectfully I don't think it was so easy. The 605A was already having problems with piston burn and overheating/seal integrity using B4 fuel, the original modification of basically upsizing the 601 internally for more power is an old engineering shortcut and the problems with it were those experienced with the 605 series until the D was developed with better oiling under the pistons and journals throughout (it was a new block from the 605A).



To my best knowledge, the problems with the DB 605A-1 were not related to the B-4 fuel. Before the new engine went operational, the earliest batch had troubles with cylinder heads burning through, but this was fixed just by the time it went into operation. The lasting problem was insufficent lubrication of the bearnings, and this probably boiled down to the more powerful oil pump of the 605s; fitting an oil dearator finally solved this in the summer-automn of 1943.

See:

http://www.kurfurst.org/Engine/Boostclearances/DB605_142ban_June1942.html
http://www.kurfurst.org/Engine/Boostclearances/DB605A_GLmeeting_September1943.html



> And here's the thing, without the improved D block and oiling you only had 1-2min of sondernot to work with, max. I saw a report once saying it shouldn't really be used at all unless the pilot is in imminent danger of being shot down.



605AM and ASM specification allow the Sondernotleistung for the same period as on the D engines: 10 minutes. 



> Also there is no evidence the 605DC or ASC were ever actually fitted to Messerschmitt in service, all evidence points to DB or ASB engines only (1850PS max sea level up to around 2000m).



That would be curious, because the DC and DB are the same engine: they only differ in how they are set up/calibrated. There's no seperate DB or DC manual - there is but one, for the DB/DC. Any DB could be converted into a DC and vica versa in no time. So I kinda doubt it, its actually a 'theory' Mr. Williams pushes but cannot prove. Even his own documentation disproves it..


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## vanir (Apr 10, 2010)

> To my best knowledge, the problems with the DB 605A-1 were not related to the B-4 fuel. Before the new engine went operational, the earliest batch had troubles with cylinder heads burning through, but this was fixed just by the time it went into operation. The lasting problem was insufficent lubrication of the bearnings, and this probably boiled down to the more powerful oil pump of the 605s; fitting an oil dearator finally solved this in the summer-automn of 1943.



I didn't say it was related to B4 fuel?? What I wrote is accurate. Also oiling does more than lubricate bearings, it cools the piston floors, helps reduce cylinder temperatures.



> 605AM and ASM specification allow the Sondernotleistung for the same period as on the D engines: 10 minutes.



apparently not in practise. The document I read specified dramatic reduction in engine life with these setups (dozens of hours), and was quite literate about the ten minute limitation on use being unrealistic, and for extreme emergencies only. The cooldown period was ten minutes.



> That would be curious, because the DC and DB are the same engine: they only differ in how they are set up/calibrated. There's no seperate DB or DC manual - there is but one, for the DB/DC. Any DB could be converted into a DC and vica versa in no time. So I kinda doubt it, its actually a 'theory' Mr. Williams pushes but cannot prove. Even his own documentation disproves it..



I'm well aware of this, although the tuning changes are important (higher boost, different magneto setups). For simplicity sake the B4/MW50 or straight C3/1550PS are referred to as the DB motor and the C3/MW50 setup as the DC. This follows general notation. What I said is true for the point there is no evidence the 605D ever used C3/MW50 in service, and there is similarly no evidentiary support for the ASC engine ever being fitted (which ostensibly follows the same rules ASB/ASC).

This wasn't my preferred assumption, I in fact argued that it is likely field use differed from red tape bureacracy particularly during the last months of the war. I cited there was no reason to my mind field mechanics could not get any G-10 or K-4 in the field and tweak it for use of C3 stocks held for 190A's, thus there is no reason there might not have been individual examples of 2000PS Me-109's running around. But the counter argument was this does not appear in any documentation, that the 605D or ASB were never cleared for use of C3/MW50 (ie. 1.98ata) in the field by the administration.

Let me put it another way for simplicity sake, saying exactly the same thing. The highest boost rating cleared for the Me109 was 1.8ata, this other business was about reiterating that C3 could not be used with an A block without MW50 because it already ran hot and burned pistons on B4 fuel, and it was a problem unrelated to predetonation (but in fact caused it).



Just curious Kurfürst, what exactly _do you_ think the difference is between the 605A and the 605D specifically, aside from the supercharger and larger oil cooler? Over 30 months of redevelopment, were they smoking joints in the back room?


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## Knegel (Apr 11, 2010)

riacrato said:


> Being the second most successful wing in history I discard your negative comments on JG*5*4 thank you. And there were plenty of the latest Russian types encountered. That the Fw 190 was so popular with this wing is even more astonishing since it entered the scenario only when it began to lose its definite superiority over the contemporaries (i. e. early 1943).
> 
> The weight difference between late Anton and Dora variants is insignificant. My data shows the Dora as slightly lighter when loaded than the Anton, I don't know what you're getting at.
> 
> And if you call boom and zoom not fighter combat than I'm very sorry for you that east, west and Pacific alike this was the preferred type of combat for anyone who wanted to stay alive




Hi,

i dont wrote anything bad regarding the JG5, its a fact that the noth front wasnt seen as important as the middle and south, as such the VVS concentrated their forces rather there. They main target was germany, not the baltics and finland at that time.

Yes, the Anton was more light than the Dora, the 190 just never got a good engine(light + powerfull in the needed altitude), as such the outstanding airframe only short time gave the pilots a real superiority and that at a time, when there was no direct frontline to the west. 

Late in 1943 the 190A was just a good plane, but already turned to be to heavy(what a outstanding wingload). That the german pilots particular did so well with it is rather related to them than to the plane. Same like the Brewster, MS405 and Hawk75 in the hands of the FAF turned to be a good weapon at a time when this planes was already badly outdated.


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## Knegel (Apr 11, 2010)

vanir said:


> Okay I'll try again. The problem was overheating which caused predetonation, it wasn't the other way around so octane wasn't a fix for the problems with the 605A. Here's what happened, the motor ran hot on B4 at more than 1.35ata and it then did two things, it predetonated under loading and it opened up the seals and flamed. C3 cannot help this.
> In order to put C3 into a 605A and up the boost you need to use MW50, so you might as well raise the boost all the way to 1.7ata which was done when MW50 was fitted from Feb44 and C3 could finally be used in the 605A.
> 
> Otherwise to use C3 just on its own you needed the D series block or else you're just going to flame the engine even if you can sort out the pinging due to higher running temperature (not the other way around). Using just C3 without MW50 you can get 1550PS out of the 605 (demonstrated), but it has to be the D block because it runs too hot for the A block.
> ...



What make you believe that the DB605A wouldnt run cooler with C3 fuel??

The overheat problems was solved and the bearing problems as well. Iam pretty much sure, if they would have had C3 fuel, they would have found a way to use it. So they did in the DB601A and in the BMW801D. They dont had it, cause the BMW+ FW190 needed it(without that plane was dead meat), as such they had to rebuild the engine to run on higher presure without C3 fuel.

Afaik the problem is not heat iselft, its the detonations that happen when the engine is hot and higher octan = higher possible temp before the detonations happen.


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## Knegel (Apr 11, 2010)

Vincenzo said:


> in the july of '43 RAF in british islands has 7 Spit IX squadrons, 8 Spit IX&V squadrons and 24 Spit V squadrons, 2 squadrons with Spit XII and 4 high altitude squadrons with Spit V,VI,VII and an other 40 squadrons with not Spit fighter. the 1st jan '44 the most common was ever Spit V but now IX was near, squadrons 24 and 20.
> the first july the most common 190, in fighter unit, was A-5 (the A-3 was less of 1/12 of all anton), the 1st january '43 the A-4 (the A-3 was around 1/5 of all anton)



Yes, and guess how it did look in late 1943 and the in late 1943 used SpitV´s was the SpitVB´s anymore, that was so much inferior in 1941/42.

The 190A5/6 was already 100-200kg more heavy than the A3, while the late SpitVc´s engine also got uprated and particular the SpitV´s was real low level beasts, with clipped wings and a powerfull Merlin50 engine.
All over the 190A lost the initiative, they wasnt able to escort bombers, cause they missed manouverability and climb ratio, and they had trouble to intercept bombers in high alt.
They just was good attackers by then.


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## Vincenzo (Apr 11, 2010)

Knegel said:


> The 190A5/6 was already 100-200kg more heavy than the A3, while the late SpitVc´s engine also got uprated and particular the SpitV´s was real low level beasts, with clipped wings and a powerfull Merlin50 engine.
> All over the 190A lost the initiative, they wasnt able to escort bombers, cause they missed manouverability and climb ratio, and they had trouble to intercept bombers in high alt.
> They just was good attackers by then.



the allied test on 190 all tell that 190 was highly manouvrable but in turning, and in high speed also the turning capablity was not bad (this is not from allied report), climb ratio of 190 in mid '43 was not so bad. what's high alt for you?


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## Juha (Apr 11, 2010)

Nothing to do with the title of this thread but
IMHO British had Fw 190A more or less under control in 43. On 1.1.43 RAF had in first line sqns in UK 162 Spit IXs, c. 200 Typhoons and a bit under 250 Mustang Is/IAs. LW had against them, IIRC, c. 250 109Gs and Fw190As. So especially in low level fighting RAF had a/c to combat LW fighters. During 43 RAF got longer range radars for fighter control over France and improved its tactics, so it’s not surprising that with increasingly powerful and effective USAAF in its side RAF began gaining upper hand during the later part of 43. On 30 Jun 43 RAF had c. 170 first class Spits (IXs, XIIs and VIIs), c. 350 Typhoons and c. 250 Mustang Is/IAs in first line sqns in UK, With 8th AF that was clearly enough against LW fighters stationed alongside NW Europe coastal areas.

Juha


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## Vincenzo (Apr 11, 2010)

Juha i'm agree that western allied have more fighter of luftwaffe but if you want tell that for this we can do'nt take in count the large numbers of Spit V in RAF side i'm not agree.

I remembered wrong and i see lw fighter for 1st july '43 and not for 1st january , but for july i find a strenght of around 700 lw fighter in western (JG 1, 2, 5, 11, 26) i see fast maybe iìm wrong in some, you're sure for 250? yours it's strenght or ready?


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## Juha (Apr 11, 2010)

Hello Vincenzo
JG 5 was in Norway, part along its western coast and part in Northern Norway and Northern Finland operating against Soviets, so it was well outside ranges of RAF single-engined fighters, IIRC also parts of JG 1/11 were outside the the ranges of RAF single engined fighters.

Juha


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## vanir (Apr 11, 2010)

> What make you believe that the DB605A wouldnt run cooler with C3 fuel??



engineering realities. For me personally, experience setting up and running race engines through various stages of modification (ie. various classes of racing). I stuck with the same engine type through all these so it was instructive particularly about running temperatures vs modification and the role of octane.

I could speak either anecdotally or simply reiterate the engineering guidelines. Increasing octane does absolutely nothing to solve a high running temperature, but it can help with pinging except for one major problem you introduced. You want to raise the octane used by the 601A to C3 fuel _and raise the boost for higher climb rating output_, to 1475PS at the climb setting no less. Aside from the fact that 605D running C3 can only manage 1300PS at steigleistung, your engine idea still runs just as hot as before, and any benefit regarding predetonation of simply raising fuel octane gets blown out of the water by use of a higher boost.
So you've got an engine which burns pistons under loading, and if it runs at high power settings for any length of time it opens up the seals and bursts into flames, which is just what the 605A used to do on B4.
So let's say you used C3 and didn't raise the boost, it has the same output as before so that's no improvement (raising octane does not improve output by itself) but it won't burn pistons as easy, then again it will be higher maintenance due to the additives being more corrosive in C3 than B4 (stipulated by German wartime fuel production/research documents available on the web). And you've still got the problem about overheat/flaming inherent to the A block. The problem was inadequate oiling for what is basically a 601E with a greater internal capacity. More cubic inches means more cfm means higher operating temperatures.



> The overheat problems was solved and the bearing problems as well. Iam pretty much sure, if they would have had C3 fuel, they would have found a way to use it. So they did in the DB601A and in the BMW801D. They dont had it, cause the BMW+ FW190 needed it(without that plane was dead meat), as such they had to rebuild the engine to run on higher presure without C3 fuel.



The overheat problems were never solved for the A block ostensibly until 1945 in the ASB/ASC, which probably uses the bottom end of the D block. The reason for the 605D development was to allow higher boost ratings to be used with the 605 engine, this is not about tensile strength but about operating temperatures. Piston burn was largely solved, but only for the throttle settings used on the 601E which were carried over to the 605A. For a little while it had to be detuned. The way they solved it was reshaping the piston crowns for better excavation of the cylinder, which helps with cylinder temperatures. It still couldn't exceed 1.42ata though, this measure just brought the 605A back to 601E tuning.



> Afaik the problem is not heat iselft, its the detonations that happen when the engine is hot and higher octan = higher possible temp before the detonations happen.



It overheated and then started pinging. If it didn't overheat it would run just fine at 1.42ata just like the 601E did. Secondly, even if the pilot carefully controlled the pinging (overheating engines ping worse under loading), like Marsielle did the overheating still caused the seals to open up and the engine flamed. The pilot could die this way, like Marsielle did.
So the motor was derated, I'd say Marsielle's death was the catalyst for this.
Even when piston crowns were improved in various batch redesigns, the engine remained derated for quite some time (it was an on again, off again situation as Kurfürst outlines citing documentation). Even when it was finally cleared for 1.42ata it was still a hot running engine compared to the 605D which has no recorded inherent reliability issues I've seen, and there are plenty of sources which state 1944 605A running with MW50/C3 had a dicey sondernot which could easily damage the engine within a few minutes. I've read nothing other than a reliable 10min sondernot for a 605D on MW50/B4 and a higher boost.
That alone should say something, and it directly infers precisely what I've been saying in mechanical terms.


Hey don't get me wrong, I'll stand corrected as readily as the next bloke, but I'm using clear logic here, with at least some historical reference and see no mechanically sound counter argument.


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## Vincenzo (Apr 11, 2010)

Juha said:


> Hello Vincenzo
> JG 5 was in Norway, part along its western coast and part in Northern Norway and Northern Finland operating against Soviets, so it was well outside ranges of RAF single-engined fighters, IIRC also parts of JG 1/11 were outside the the ranges of RAF single engined fighters.
> 
> Juha



i checked the bases of JGs (only1,5,11), for JG 5 it's ok Norge it's away, for JG 1 i think all the bases are enough near for take in the battle (some are a bit away but the fighters don't fight only over their fields), for JG 11 i think that only II was enough near, so we have a strenght of 450 fighters in 1st jan '43 (1, 2, 26) and of 480 fighters in 1st july '43 (same more +II/11)


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## Juha (Apr 11, 2010)

Hello Vincenzo
IIRC JG 11 was formed in spring 43, and at the beginning of 43 III/JG 1 was at Kjevik, which sounds definitely Scandinavian name, I and IV/JG 1 were in NW Germany and IMHO much more headache of 8th AF than RAF so IMHO at the beginning of 43 JG 2, 26 and II/JG 1 were units that were major opponents of FC.

In 1 July 43 LW had some 980 serviceable fighters, it had one Geschwader in Scandinavia (5), 3 in MTO (27, 53 and 77) and at least 4 in Soviet Union (3, 51,52 and 54) and something in Germany so IMHO 480 capable to operate regularly against FC is too high number. Without checking I would guess 300+ would be nearer to truth.

Juha


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## Vincenzo (Apr 11, 2010)

Juha said:


> Hello Vincenzo
> IIRC JG 11 was formed in spring 43, and at the beginning of 43 III/JG 1 was at Kjevik, which sounds definitely Scandinavian name, I and IV/JG 1 were in NW Germany and IMHO much more headache of 8th AF than RAF so IMHO at the beginning of 43 JG 2, 26 and II/JG 1 were units that were major opponents of FC.
> 
> In 1 July 43 LW had some 980 serviceable fighters, it had one Geschwader in Scandinavia (5), 3 in MTO (27, 53 and 77) and at least 4 in Soviet Union (3, 51,52 and 54) and something in Germany so IMHO 480 capable to operate regularly against FC is too high number. Without checking I would guess 300+ would be nearer to truth.
> ...



for JG 11 true this is the reason beacuse in 1st jan '43 it were not in the sum. true kjevik it's near oslo, jever it's not so away 280 miles from norwich, gladbach is 260 miles from ipswich, deelen it's a 250 miles (and if it's the dutch deelen it's a 200 miles), rheine is a 270 miles. so take out the III/JG 1 we have around 400 fighter in 1st january '43, for the 1st july ever 480 (the III/JG1 go back in nederland). the 1st july '43 the strenght of jagdverbande was around 1800 fighters.


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## Juha (Apr 11, 2010)

Hello Vincenzo
As I wrote, the number of serviceable single engine fighters was 980 according to Price, see Luftwaffe Order Of Battle on 17 May 1943 - The Air Combat Wiki
My memory made a trick on date , the right one is 17 May 43, Price usually gives July figure but not for 43.

But you are right that LW had in its first line units 1849 single-engine fighters on 30 June 43 according to Williamson Murray. If the Price’s figure is correct, LW serviceably rate was even worse than I remembered, c. 55% (I used 31.5.43 strength figure as a base) 27 May was a bit bad date for LW, for ex JG 77 was in very bad shape. On 31 Aug 43 serviceable rate was 64,4% (1019 out of 1581 according to Williamson Murray.

Juha


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## Bug_racer (Apr 11, 2010)

vanir said:


> engineering realities. For me personally, experience setting up and running race engines through various stages of modification (ie. various classes of racing). I stuck with the same engine type through all these so it was instructive particularly about running temperatures vs modification and the role of octane.
> 
> I could speak either anecdotally or simply reiterate the engineering guidelines. Increasing octane does absolutely nothing to solve a high running temperature, but it can help with pinging except for one major problem you introduced. You want to raise the octane used by the 601A to C3 fuel _and raise the boost for higher climb rating output_, to 1475PS at the climb setting no less. Aside from the fact that 605D running C3 can only manage 1300PS at steigleistung, your engine idea still runs just as hot as before, and any benefit regarding predetonation of simply raising fuel octane gets blown out of the water by use of a higher boost.
> So you've got an engine which burns pistons under loading, and if it runs at high power settings for any length of time it opens up the seals and bursts into flames, which is just what the 605A used to do on B4.
> ...




This has become an interesting engine thread  

Increasing octane does absolutely nothing to solve a high running temperature

Wrong : Increasing the octane will allow a slower burning flame front that will produce lower Exhaust Gas Temperatures which in turn will radiate less heat . The combustion temperature will also be reduced . Especially if the engine is close to pre-detonating . 



So you've got an engine which burns pistons under loading, and if it runs at high power settings for any length of time it opens up the seals and bursts into flames, which is just what the 605A used to do on B4 :

I dont understand the opens up the seals and bursts into flames bit ? 
My assumption : Running higher boost pressures causes the piston rings to warp allowing more combustion pressures to leak past the rings into the oil sump pushing oil out of the breather and probably over the exhaust manifold causing fires ? I doubt the piston would burn a hole before the rings fried first . 


raising octane does not improve output by itself : It actually does albeit a small amount . You can lean it out and change the timing on the engine to get the most out of it . 

More cubic inches means more cfm means higher operating temperatures :
Raising capacity doesnt mean you have more to cool . A 24l engine running 5:1 compression ratio at 2000rpm will make far less heat than say a 5l engine running 15:1 compression at 10000 rpm . Heat is a factor of 3 main things : Engine size , combustion temperatures (fuel used and compression ratio) and RPM , there are other smaller factors of air flow over engine , radiator size etc 


Does anyone know if the Pistons were forged or cast ?


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## Shortround6 (Apr 11, 2010)

Bug_racer said:


> raising octane does not improve output by itself : It actually does albeit a small amount . You can lean it out and change the timing on the engine to get the most out of it .



Airplane engines are not car engines. While the basic principles are the same some of the details are not.

For instance on many aircraft engines of the time the timing was fixed. If the specs called for 20 degrees before top dead center that is what it was set to and that is what the engine ran at. 600rpm idle or 3000rpm. 1500rpm cruise at 5,000ft or 3000rpm at 30,000ft. 
Supercharged aircraft engines are not leaned out for power. At full throttle in many cases they are being fed 30-50% more fuel than they can actually burn in the air available. The extra fuel acts as an anti-detonat in the intake tract (not available to most German engines) by cooling the intake charge due to evaporation. it also acts like an internal coolant in the cylinder, again by absorbing heat but now it is carrying it out the exhaust system. A reason that many aircraft engines trail black smoke from the exhausts at or near full throttle.

Then there is the whole dual number rating thing. Some allied fuels acted like 100 octane (or performance number)when lean and acted like 130 when running in a rich condition. This is not automatic, it depends on the composition of the fuel. before this was fully understood there were actually a few batches of fuel delivered to the US (who had a different fuel spec on the amount of allowable aromatics than the British) That actually would up performing at a lower octane rating when running rich than running lean.


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## vanir (Apr 12, 2010)

> Wrong : Increasing the octane will allow a slower burning flame front that will produce lower Exhaust Gas Temperatures which in turn will radiate less heat . The combustion temperature will also be reduced . Especially if the engine is close to pre-detonating .



Not on an open exhaust with good cylinder excavation, and altering boost will get a much greater impact on EGT anyway. (edit) and actually now I'm thinking about it, a higher EGT is actually desireable for lowering combustion chamber temperatures, it helps excavation quite a bit.
In my race engines raising octane didn't solve high running temperatures, I had to get the head reflowed (ports were slowing excavation at the greater cfm). Also I had to increase the radiator volume and was told my setup was oversize for the oil journal drilling of the basic block (I tried bigger sump and playing with the oiling as best I could). This was for the same engine bored/stroked but tuned to the same spec, a good parable for the DB-601E to the 605A trying to run the same tuning. Raising octane didn't help running temperatures one bit, I tried it.

Raising octane did help with the pinging I got with the bigger capacity on 105 grade (I took it up to ~120 grade for track work), but it still ran just as hot and that was killing off a ton of horsepower (~15%). In fact, and this is an entirely anecdotal statement, I swear black and blue it ran even hotter on the higher octane but did ping less (I could control this on the throttle, since I used vacuum slide valve carbs, and also by reducting intake). Proof of this was the fact I had to run cooler plugs on high octane in track tuning than I did for street cruise and pump grade (much more retard though, you're right for that). Also if it helps I used a mechanical ignition system pretty much identical to a aero magneto setup.
So as it turned out I was actually less competitive with a bigger capacity than I was at the smaller one (which had nicer harmonics at high rpm), until I solved the high running temp. Fixing that was what made all the difference, hence my view is the 605D was the proper development of the larger capacity version of the 601 and the 605A was only halfway there.



> I dont understand the opens up the seals and bursts into flames bit ?



It opened all the block seals (eg. mainseal) with overheating if run at high boost settings for an extended period, spraying oil backwards over the exhaust and flaming. This is documented.
If you took comprehensive guaging of the temperatures, the oil would run high from the word go, the water would run high at normal power settings and the cylinder head/block temperature would go through the roof at high power settings. A lot of the heat problem in the cylinder is coming from the crank and pistons (not from the combustion chamber), due to inadequate oiling as a cooling effect. The journals were drilled for the 601 cfm flowing 1200-1300PS and not the 605 cfm flowing 1350-1475PS (not to mention it was always intended that it would be taken out to at least 1550PS).

I am saying categorically, a point of which to my mind there is absolutely no question. High combustion chamber temperatures in the 605A are caused by high block/piston temperatures and not high intake temperatures, poor excavation or high EGT. The fact it even flows 1475PS suggests an excellent excavation.
Hence I am equally adamant the primary difference between the 605A and 605D blocks are the oil journal drilling (water jackets are only going to help cylinder head temp, which doesn't solve our oil seals issue).



> raising octane does not improve output by itself : It actually does albeit a small amount . You can lean it out and change the timing on the engine to get the most out of it .



Incorrect. Raising octane reduces output by a slight amount in point of fact. I can model this for you if you like and show you the difference in graph. All high output engines run at the lowest possible octane to get the most horsepower (race engine building 1:01 dude), but predetonation and usable/ideal ignition timing dictates the minimum octane. What raising octane allows you to do is advance the ignition more for a lower rpm torque band, but if you're already running an ideal torque band/rpm range then this is no good. It also lets you raise boost or dynamic compression for a total net gain even though the initial raising of octane actually lowers your base output.

It's like this, on a say 300hp engine you drop to 293hp raising octane but what you do is raise boost from 1 bar to 1.2 bar for a net return of 330hp.
Alternatively on an engine producing 400ft/lbs at 3000rpm but 250ft/lbs at 2500rpm you raise octane and advance timing for 385ft/lbs at 3000rpm and 300ft/lbs at 2500rpm. Much quicker in acceleration off the mark but you might lose a touch coming out of fast turns (picking it up coming out of slow turns, you get the idea).

Also you don't lean out when raising octane if you're in it for the output (you could do that for cruise efficiency, you'll get more out of a tank), what you do is advance the timing (or raise your dynamic compression).



> Raising capacity doesnt mean you have more to cool .



More cfm means more heat. The easiest way to get more cfm is more cubic inches. This is a rule of thumb. Generally speaking larger capacity engines are a larger external block, so that solves the higher running temperatures with having more meat.
It becomes a problem with stroker engines, or raising swept capacity on a common block. It's elementary.


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## Bug_racer (Apr 12, 2010)

vanir said:


> Not on an open exhaust with good cylinder excavation, and altering boost will get a much greater impact on EGT anyway. (edit) and actually now I'm thinking about it, a higher EGT is actually desireable for lowering combustion chamber temperatures, it helps excavation quite a bit.
> In my race engines raising octane didn't solve high running temperatures, I had to get the head reflowed (ports were slowing excavation at the greater cfm). Also I had to increase the radiator volume and was told my setup was oversize for the oil journal drilling of the basic block (I tried bigger sump and playing with the oiling as best I could). This was for the same engine bored/stroked but tuned to the same spec, a good parable for the DB-601E to the 605A trying to run the same tuning. Raising octane didn't help running temperatures one bit, I tried it.
> 
> Raising octane did help with the pinging I got with the bigger capacity on 105 grade (I took it up to ~120 grade for track work), but it still ran just as hot and that was killing off a ton of horsepower (~15%). In fact, and this is an entirely anecdotal statement, I swear black and blue it ran even hotter on the higher octane but did ping less (I could control this on the throttle, since I used vacuum slide valve carbs, and also by reducting intake). Proof of this was the fact I had to run cooler plugs on high octane in track tuning than I did for street cruise and pump grade (much more retard though, you're right for that). Also if it helps I used a mechanical ignition system pretty much identical to a aero magneto setup.
> ...





and actually now I'm thinking about it, a higher EGT is actually desireable for lowering combustion chamber temperatures, it helps excavation quite a bit.

There is a desired egt at which the engine operates at its most efficient . If you run too higher egt your probably pinging/predetonating . Its kind of like the same as engine operating temperature . The desired water/coolant temp is around 90-100 , any more than that becomes damaging to the coolant system . 
Raising octane is to help in the combustion temperature , not engine operating temperatures . Combustion temperatures should decrease slightly . The effects are minimal though . Dumping more fuel in to cool the combustion chamber down would be more effective , as would water/meth injection .



Raising octane did help with the pinging I got with the bigger capacity on 105 grade (I took it up to ~120 grade for track work), but it still ran just as hot and that was killing off a ton of horsepower (~15%

This shows you your egt's are too high which affects your hp . When searching for hp there are safe limits , go beyond these limits you just loose power and run too hot . My personal opinion , back the timing off a few degrees and run it a bit richer and you'll probably run cooler and make the same if not more hp . Are you running carbs ? What ignition system ?




It opened all the block seals (eg. mainseal) with overheating if run at high boost settings for an extended period, spraying oil backwards over the exhaust and flaming

This to me says there are more issues with the breather system than anything else . Im not too sure what system they used but some pics of it would be nice  . 



Incorrect. Raising octane reduces output by a slight amount in point of fact. I can model this for you if you like and show you the difference in graph

I dont understand how this is possible when there is more energy per volume with higher octane fuels ? The effects I admit are minimal anyway so its a waste to just run high octane fuel without making any changes . 





All high output engines run at the lowest possible octane to get the most horsepower (race engine building 1:01 dude),

Im sure you mean it the other way round ! Highest possible octane available for the class ! Have you noticed how many racers are converting to ethanol or E85 now that its more widely available ? yes you need bigger injectors and more fuel (almost as much as Methanol!) But its still considered pump gas and has octane of 110 or so . 


It's like this, on a say 300hp engine you drop to 293hp raising octane but what you do is raise boost from 1 bar to 1.2 bar for a net return of 330hp.
Alternatively on an engine producing 400ft/lbs at 3000rpm but 250ft/lbs at 2500rpm you raise octane and advance timing for 385ft/lbs at 3000rpm and 300ft/lbs at 2500rpm. Much quicker in acceleration off the mark but you might lose a touch coming out of fast turns (picking it up coming out of slow turns, you get the idea).

I think your getting compression ratio confused with octane here . If you lower the compression ratio of an engine and run the same boost pressure you will loose peak power and torque , say your running a turbo (I dont think it will affect a supercharged engine the same ) , your boost will come on later and you will have less , but you can raise the boost pressure and run the same octane rating of fuel to gain an overall raise in the amount of power . Lowering the compression ratio also adds to the longetivity of an engine . In regards to the timing it really depends upon the cams etc as to what works best . You can though add more advance with higher octane fuels . 



More cfm means more heat. The easiest way to get more cfm is more cubic inches. This is a rule of thumb. Generally speaking larger capacity engines are a larger external block, so that solves the higher running temperatures with having more meat.
It becomes a problem with stroker engines, or raising swept capacity on a common block. It's elementary.

If the engines dont have problems with cooling standard then they usually can handle the extra volume from boring / stroking . Its rpm/compression increases that really give issues with heat . The issues your probably seeing with extra heat from boring/stroking are probably engines still injecting the same amount of fuel before the modification and having extra airflow causing them to run too lean


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## Vincenzo (Apr 12, 2010)

Juha said:


> Hello Vincenzo
> As I wrote, the number of serviceable single engine fighters was 980 according to Price, see Luftwaffe Order Of Battle on 17 May 1943 - The Air Combat Wiki
> My memory made a trick on date , the right one is 17 May 43, Price usually gives July figure but not for 43.
> 
> ...



good link, ty, i checked with ww2.dk and there are some minor wrongs (as unit with 109 indicated with 190 but maybe a wrong from web compilator). 
i thinked that our difference came from different status, strenght or ready planes and so i've asked you but you don't replyed me.
we have in 17 may around 280 ready fighters (2,26 (but I/26),1 and II/11 and 11/54) with a 370 fighters strenght

for serviceablity i can add that for 17th may we have 1493 strenght fighter and 1032 serviceable so 69%
se serviceable are 980 (this is w/o jabos and fighters in reforming unit) the strenght it's 1355 and serviceability rate go to 72%


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## Kurfürst (Apr 12, 2010)

Juha said:


> Nothing to do with the title of this thread but
> IMHO British had Fw 190A more or less under control in 43. On 1.1.43 RAF had in first line sqns in UK 162 Spit IXs, c. 200 Typhoons and a bit under 250 Mustang Is/IAs. LW had against them, IIRC, c. 250 109Gs and Fw190As. So especially in low level fighting RAF had a/c to combat LW fighters. During 43 RAF got longer range radars for fighter control over France and improved its tactics, so it’s not surprising that with increasingly powerful and effective USAAF in its side RAF began gaining upper hand during the later part of 43. On 30 Jun 43 RAF had c. 170 first class Spits (IXs, XIIs and VIIs), c. 350 Typhoons and c. 250 Mustang Is/IAs in first line sqns in UK, With 8th AF that was clearly enough against LW fighters stationed alongside NW Europe coastal areas.
> 
> Juha



Interesting figures Juha, the RAF first line strenght remains somewhat of a mystery, although we can gauge fairly accurately to ratio of moden and semi-obsolate fighters during 1943 from the number of Squadrons operating them.

Do you have perhaps even more detailed figures for all types of fighters and their servicability at that date, ie. the number of Fives and their servicibilty etc? It would be really nice to see actual figures for both sides.

Ie. the 162 Spit IXs in January 1943 agrees well with 10 Spit Mark IX Squadrons listed operating them. Theoretically the 10 Squadron establishment should around 200-220 Spits present, of which there appears that ca 160 could be maintained. British practice was also different from German - Squadrons had an establishment of 20-22 planes per fighter Squadron, but these included the Sqn's immidiate reserve aircraft, and in practice, without exception 12 or sometimes 13 aircraft would fly mission from a Squadron. There's no doubt that the RAF had enough fighters to against the small "guerilla" JGs stationed in France (which had no importance to the Germans), but the mission logs I've seen it appears that Mark Vs continued to fly the majority of the sorties until the end of 1943. Tiffies and Allisonstangs flew as well, but primarly as fighter bombers to my knowledge - save for anti-Jabo Tiffies of course.


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## claidemore (Apr 12, 2010)

Kurfürst said:


> Interesting figures Juha, the RAF first line strenght remains somewhat of a mystery, although we can gauge fairly accurately to ratio of moden and semi-obsolate fighters during 1943 from the number of Squadrons operating them.
> 
> Do you have perhaps even more detailed figures for all types of fighters and their servicability at that date, ie. the number of Fives and their servicibilty etc? It would be really nice to see actual figures for both sides.
> 
> Ie. the 162 Spit IXs in January 1943 agrees well with 10 Spit Mark IX Squadrons listed operating them. Theoretically the 10 Squadron establishment should around 200-220 Spits present, of which there appears that ca 160 could be maintained. British practice was also different from German - Squadrons had an establishment of 20-22 planes per fighter Squadron, but these included the Sqn's immidiate reserve aircraft, and in practice, without exception 12 or sometimes 13 aircraft would fly mission from a Squadron. There's no doubt that the RAF had enough fighters to against the small "guerilla" JGs stationed in France (which had no importance to the Germans), but the mission logs I've seen it appears that Mark Vs continued to fly the majority of the sorties until the end of 1943. Tiffies and Allisonstangs flew as well, but primarly as fighter bombers to my knowledge - save for anti-Jabo Tiffies of course.



Just looking at the sample of combat reports on Mikes site I see 8 squadrons with MkIXs in January 1943. From Mikes sampling of combat reports for the year 1943 I count 22 different squadrons using Mk IXs. This is not a total list, just a sample, and units would have rotated in and out of front line service.
According to the 2TAF order of battle only one 'front line' squadron, Czech 310 was using MkV's during June 1944. They flew some ground attack at Normandy from Tangmere, and never did operate out of a European base. This was basically a reserve squadron. 
June 1944 there were 25 Spit IX squadrons on front line service, 5 Spit IX squadrons in reserve, and 7 Spit V squads in reserve. Two Tempest V squadrons, 6 Mustang III squads, 17 Typhoon squads, two Spit XIV squads and a few miscileaneous squads flying Spit IXs, Vs, etc.
One of the 7 Mk V squads was 402, which according to squadron history was flying Mk IXs at that time. Ditto for 501 Sq. All the other Mk V reserve squads had converted to either Mustang II's, Mk IXs , Mk XIVs or Tempest V by August of 44. 
Here's a link that shows RAF squadrons and types with dates. RAF Fighter Command Index Shouldn't be too hard to add up the MkIX and MkV squadrons during 1943 using that site.


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## Vincenzo (Apr 12, 2010)

as already writed there were 20 squadrons with Spit IX in 1st jan '44 (was not uncommon that a squadron with IX back to V ) and 9 in january '43 (+2 mixed with V and VI) this only in british islands.


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## VG-33 (Apr 12, 2010)

gumbyk said:


> Sorry, I can't see any more similarity beyween these two aircraft, and any other two radial engined, low-winged fighters of the time:
> 
> 
> 
> ...



As a whole, i agree with you.
I just want to point at a detail:

Unlike the La-7, the La-9 had no combat slats that are represented at your draw. The reason is that he had a laminarised TsAGI wing and fin profiles, that explains also it's Mustang-like square wing tips. It's difficult to keep laminar conditions on rounded shapes. Carrying much more fuel the plane was heavier 3675 kg unstead 3250 but it's range was 1 735 km instead of 635/990. The La-7 in turn was a pure Close-in tight high -G frontal fighter, with no escort mission ability.











This sovietmade kind of "mustang" was intended to use a Shvetsov M-83 engine, reaching 725 km/h with it, since the serial La-7 was able to give only 701-705 km/h using the same one. Even qualified at state trials this engine for some valuable reasons and some not, was never to be mass-produced.

Even without it, using the old M-82T and without combat slats, from Mark Hannah and french collectors opinion like Christophe Jacquard, Jean Salis, Didier Chables and others it's one of the nimbliest warbirds ever flown...At least at Spitfire level, except for roll that's much better of course for the soviet plane.

So it could outurn and outfight the FW-190A-8 with ease when reduced to the La-7 weight, the better manufacturing quality and some improvements in the late M-82 FN engine allowed to consider the "forsage" output as a nominal one : 640 km/h at SL at 1850-1870 hp. 600 km/h at ~ 1615 hp at SL in nominal power "max continuous course" by soviet standards.

Regards


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## Juha (Apr 12, 2010)

Hello Vincenzo
thanks for your effort, I’m now too busy to make my own calculations, so I just took some ready figures from a couple good sources that first came into my mind. I had seen Price’s figures in net a rather long time ago and decided to give the link to you and googled LW OoB and found that Wiki page It wasn’t the site I was looking for but seemed interesting, I’ll look it again later for its late OoBs.

Hello Kurfürst
I calculated those figures from OoBs in Foreman’s FC War diaries Jan 42 to June 43 plus made some cross-checking with my decades old notes on info on RAF a/c stocks. It would be easy to add the info on Mk Vs if I had time but that is scare now.

IMHO Mk Vs could well be used in 43 at least as close escorts to British medium bombers. They lacked some acceleration but turned almost as well as Mk IXs and rolled as well and that was IMHO what was needed for the rather passive role of close escort. Their use in a more active role as escort cover was more problematic. IMHO Mk V with +16in boost was OK against 109G at height band 6500-13500ft and against 190A-5 at height band 10000-13500ft. The duty of Mk IX sqns was to protect escorts from attacks above as high escort cover and also try to disrupt LW attack formations and engage them before they could attack other escorts and /or bombers. I also think that in at least early 43 most of the escorts were Mk Vs, say 4 close escort sqns plus 2 escort cover sqns, only 2 high escort cover sqns had Spit IXs, or at least that was fairly typical case IIRC. RAF clearly could have used more Mk IXs if it has had them. Clearly MTO at that time sucked Merlin 60-series Spits away from FC but it also sucked in LW fighters. 

Again IIRC 43 was the year when Typhoon’s role chanced from fighter to mainly fighter bomber. Mustang Is/IAs made mostly tac recce and long range nuisance raids relying mostly strafing. But its long time ago when I read on RAF’s use of Allison Mustangs.

Juha


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## Milosh (Apr 12, 2010)

RAF total strength of Merlin 45 type and 60 type Spitfires as of 3rd September 1943.

3,312 Spit V and VI
1,525 Spit VII, VIII, LF VIII, IX and LF IX

via Niel Stirling

Data for end of November 1943, including Ergänzungsgruppen:
1397 Bf109 (all subtypes)
563 Fw190 (all subtypes)

via yogy


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## Knegel (Apr 13, 2010)

vanir said:


> It overheated and then started pinging. If it didn't overheat it would run just fine at 1.42ata just like the 601E did.


The 601E did overheat on 1.42ata, thats why it was limited to a few miniutes on this setting, called WEP.
All engines overheat on WEP to a stage where detonations happen, the normal way to be able to run on the same setting for longer time was to use higher octan fuel. 



vanir said:


> A side from the fact that 605D running C3 can only manage 1300PS at steigleistung,....
> 
> 
> vanir said:
> ...


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## claidemore (Apr 13, 2010)

Totally off the La9 topic, but the thread seems to have sprouted this rabbit trail. 

Spent the evening going through the RAF Fighter Command plane types for Europe during 1943.
10 squadrons flew the Spitfire Mk IX exclusively in 1943. 
5 squadrons flew the Mk V exclusively during 1943. 
28 squadrons flew both the Mk V and the Mk IX,( majority of those flew the V early in the year and switched to the IX during the middle months of 43. There were a few who started 43 with IXs then rotated back to Mk Vs.)
Several other squadrons flew Mk VI, VII or XII Spitfires, combinations of Mk Vs and Mustangs etc. 
Total of 51 squadrons flew Spitfires of various marks during 1943 (a few squadrons were renamed so there are some duplicates in that number)
Add to that 20 squadrons flying Typhoons.

Note: these are for Fighter Command, Northern Europe and does not include other theatres unless I missed a squadron that moved out of ETO during 43.


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## Juha (Apr 13, 2010)

Hello Kurfürst
made a quick check on Typhoons and yes it was only in autumn 43 when conversion from fighter to fighter-bomber duties began in earnest, before that their offensive work was mostly fighter sweeps, circuses etc even if the first two Typhoon fighter-bomber sqns were formed tiwards end of 42.

Juha


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## Vincenzo (Apr 13, 2010)

claidemore said:


> Totally off the La9 topic, but the thread seems to have sprouted this rabbit trail.
> 
> Spent the evening going through the RAF Fighter Command plane types for Europe during 1943.
> 10 squadrons flew the Spitfire Mk IX exclusively in 1943.
> ...




this are the squadrons with IX alone in jan '43: 64,122,306,315,331,332,340,402,611, so you conted 10 you can tell me what's the 10th? (i've 403 with both V and IX, and 124 with VI IX)
as that 1st january '44 there are 20 Spit IX squadrons and 10 or 9 has IX in january '43 we have that of the 28 only a part go to V to IX for remain with IX


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## Kurfürst (Apr 13, 2010)

Milosh said:


> RAF total strength of Merlin 45 type and 60 type Spitfires as of 3rd September 1943.
> 
> 3,312 Spit V and VI
> 1,525 Spit VII, VIII, LF VIII, IX and LF IX
> ...



I think the RAF strenght is something different, including aircraft in storage (having some of those tables provided by Stirling, there seems to be lot of retired Spit Is etc. appearing in those), whereas the LW strenght is aircraft issued to units (including the OTU Ergänzungseinheiten), but not reserves, storage, retired aiframes etc.


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## Kurfürst (Apr 13, 2010)

vanir said:


> apparently not in practise. The document I read specified dramatic reduction in engine life with these setups (dozens of hours), and was quite literate about the ten minute limitation on use being unrealistic, and for extreme emergencies only. The cooldown period was ten minutes.



I am not sure if I have seen those, could you share it?



vanir said:


> I'm well aware of this, although the tuning changes are important (higher boost, different magneto setups). For simplicity sake the B4/MW50 or straight C3/1550PS are referred to as the DB motor and the C3/MW50 setup as the DC. This follows general notation.



Do you know perhaps the exact tuning changes required?



vanir said:


> What I said is true for the point there is no evidence the 605D ever used C3/MW50 in service, and there is similarly no evidentiary support for the ASC engine ever being fitted (which ostensibly follows the same rules ASB/ASC).



I am not sure about the ASB/ASC, though some sources like Prien claim this, however the 605D/C3/MW50 case is pretty clear, it was used. See:












vanir said:


> This wasn't my preferred assumption, I in fact argued that it is likely field use differed from red tape bureacracy particularly during the last months of the war. I cited there was no reason to my mind field mechanics could not get any G-10 or K-4 in the field and tweak it for use of C3 stocks held for 190A's, thus there is no reason there might not have been individual examples of 2000PS Me-109's running around. But the counter argument was this does not appear in any documentation, that the 605D or ASB were never cleared for use of C3/MW50 (ie. 1.98ata) in the field by the administration.
> 
> Let me put it another way for simplicity sake, saying exactly the same thing. The highest boost rating cleared for the Me109 was 1.8ata,



Of course it was. The december 1944 DB 605DB/DC manual notes 1.98ata as the maximum for the 605DC configuration






as well as the January 1945 Daimler-Benz records noting it was cleared for service, but it was recalled in January due to some problems, which I believe were spark plug QC related. It was then successfully tested in Rechlin, field tested by II/JG 11, and cleared for service by March 1945 the latest, see: Kurfrst - OKL, GdJ-Grp. Qu-, Br. B. Nr. 1561/45 g.Kdos. von 20. Mrz 1945.



> this other business was about reiterating that C3 could not be used with an A block without MW50 because it already ran hot and burned pistons on B4 fuel, and it was a problem unrelated to predetonation (but in fact caused it).



The 605AM manual notes that C-3 can be used without MW-50 in an emergeny at full boost, but you are probably right about higher temperatures; however its not fuel related (the advantage of using C-3 was that it could sustain higher boost without pre-detonation), but the fact that MW-50 injection apart from its charge cooling benefits also gave the engine a tremendeous cooling boost as the water evaporated in the combustion chamber and draw heat away. In fact the DB datasheets show that cooling requirements of the 605A at 1800 PS/1.7ata with MW-50 injection are actually lower than the cooling requirements of the engine at 1310 PS/1.3 without MW-50 injection!



> Just curious Kurfürst, what exactly _do you_ think the difference is between the 605A and the 605D specifically, aside from the supercharger and larger oil cooler? Over 30 months of redevelopment, were they smoking joints in the back room?



I don't know all details, but know that the 605D used several other parts from the DB 603, and the compression ratio was also higher, 8.5 vs 7.5. But I don't have a document comparing the A-series and the D-series. Also keep in mind, the D-series was under development parallel to the DB 605A, being initially a variant using C-3 avgas as opposed to B-4. It went through quite a lot of changed between 42 and 44.


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## claidemore (Apr 13, 2010)

Vincenzo said:


> this are the squadrons with IX alone in jan '43: 64,122,306,315,331,332,340,402,611, so you conted 10 you can tell me what's the 10th? (i've 403 with both V and IX, and 124 with VI IX)
> as that 1st january '44 there are 20 Spit IX squadrons and 10 or 9 has IX in january '43 we have that of the 28 only a part go to V to IX for remain with IX



Hi Vincenzo, I have 403 squadron converting to Mk IXs January 43, and continuing with the IX and XVI till wars end. They might have had a few Mk Vs early in the year.
124 Sq I have with IX and VIIs (not VI's).


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## Vincenzo (Apr 13, 2010)

claidemore said:


> Hi Vincenzo, I have 403 squadron converting to Mk IXs January 43, and continuing with the IX and XVI till wars end. They might have had a few Mk Vs early in the year.
> 124 Sq I have with IX and VIIs (not VI's).



i've 403rd flying with V until january '43 included so maybe they has the V early in jan and not in late jan.
for the 124th i've VII only form march '43 and VI until july '43


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