So what's the difference between G10 and the 109K?

[Nashwan]

I highly doubt it would say anything before June 1942, simply `cos the plane did not see service before June 1942...

Well, the instruction banning 1.42 ata also talks about modifying the engine, and says:

Modifications to be carried out by the troops in case of aircraft already supplied

They certainly seem to think the planes were already in service.

Your nicely crafted story is basically that the 1.42ata is, according to you, supposed to be 'in the G-2s manual' (which you have never seen...) before it even saw service, and then it was called back, because of the troubles in service.... I see some conflicting elements in your version

Isegrim, you don't seem to understand the point. The 109G2 was supposed to use 1.42 ata. It wasn't allowed to, hence the RLM message banning 1.42 ata because of engine breakdowns.  

There isn't much point arguing, becuase you've admitted yourself the point I was trying to make when you said:

unless there is any other order that actually says 'don`t use 1.98ata vs. as said in the manual'

Manuals can be superceeded. Wether the G2 manual was superceeded, or wether it hadn't yet been published, is immaterial, the G2 was derated from it's expected 1.42ata to 1.3ata.

The Merlin III was supposed to be cleared for +12 lbs WEP, then it was severly restricted because of operational troubles, special report has to be written after every use... otherwise for strictly combat for short periods, more than +9 was FORBIDDEN.

No, the Merlin III was designed for 6.25 lbs, and had it's rating increased to 12 lbs in service. Can you find some documents showing it was originally intended for 12 lbs boost?

Proof of the fact that 12 lbs was never intended is the fact that modified boost controls had to be fitted to enable the extra boost, if the engine had been designed for it then a limiter would have been fitted to prevent the use of 12lbs boost.

Also, of course, 100 octane was necessary to prevent detonation, and the RAF didn't switch over to that until March 1940.

The Merlin 6x series were supposed to run at +18lbs, yet for about a year they had put up with +15 lbs until 1943.

No, the Merlin 61 was designed for 15lbs boost. Later 60 series engines increased it.

Isegrim, it's easy to find references like the G2 at 1.42ata, the 190A4 at 1.45 ata, and references to them being downrated. Where are your references to the the Spit I being downrated, or the Merlin 61 being downrated to 15lbs? All I can find, even in the earliest Spit tests, are references to lower boosts that get increased as the war progresses. The opposite is true of some  German engines.

The Griffon 65 series was supposed to run at +25 lbs, yet in service, AGAIN for ball bearing troubles they were restricted in service use to +21lbs

Isegrim, more than 18lbs required 150 octane. The Griffon 65 was in production long before 150 octane was. It was designed for 18lbs boost, and increased to at least 21 lbs. Can you find a reference to the Griffon 65 at 25 lbs?

So the difference between you and me is that I don`t claim anything regards the conditions I don`t know, why you make up these conditions yourself to keep ignore the result.. And I post the same figures butch and others do. I wonder what could be wrong with them? Maybe the part : 377 mph at SL? Compared to 358 mph for the Spit XIV?

No, Isegrim, the difference is there's a Spitfire XIV chart showing 397 mph at sea level, but you want to discount it because you don't know wether the Griffon 65 could use 25lbs boost.

The best figure available for the K4 at sea level is 377 mph, and you persist in using that despite very little info about the conditions it was achieved under, and wether it was actually used in combat, certainly Butch is implying it was rare.

The best figure for the Spit XIV is 396 mph at sea level, but you want to discount it because you don't know how common it was in real life. See the hipocrisy? There's another Spit XIV figure of 387 mph at sea level, but you want to ignore that as well.

You have a single document for the 109, which shows 377mph, and you accept it as gospel, you have a doc that shows 396 mph for the Spitfire, another that shows 389 mph, and you accept 358 mph. That's hipocracy, Isegrim.

This is the reason I believe the 109K4 was rarely able to match the figures in Isegrim's chart.

No, the reason is, the ONLY reason is, briefly, is that the K-4 is faster than MkXIV at SL even if one takes the highest operational boost for the Spit, and lowest operational boost for the Messer.

Sorry Isegrim, the highest speed for a Spit XIV at sea level is 397 mph. http://www.fourthfightergroup.com/eagles/spit14pt.html

I accept that might be slightly faster than normal service use, it's probably for a clipped wing aircraft without a mirror, which is why the supply ministry list 389 mph at sea level.

Not really. The DB 605DC was working on MUCH higher compression ratios than the Merlin,which was as low as 6:1 (DB 605D was 8.5:1, even the earliest DBs run at higher than 6:1...).. which means by the time of detonation, the pressure within the engine is higher in the DB 605 than in the Merlin, even w/o taking into account the higher compression also leads to higher tempretures, which makes the gas expand, increasing pressure further. Not to mention water injection works a bit different than just raising rich mixture`s critical octane rating.

Which is what I was taking into account when I said similar pressures. The Merlin was of course running much higher manifold pressure than the Db.

1.98 ata in the Db, around 2.8 ata in the Merlin with 150 octane. In lbs/sq in, about 14 for the DB, 25 for the Merlin.

[Angus]

Nashwan:you are the winner!
Hehe, it reminds me of debates of Spit vs 109 origin where Barbi types would claim everything in the 109's favour in the climbing department, superior wing, superior engine, superior prop, superior aerodynamic design, however, there was never an explanation to the FACT that the little spitty pulled the Newtons better to altitude..
Anyway, in a thread like this, where is Niklas?

[MiloMorai]

As I said Scholzie, one has to be very careful with what Barbarossa Isegrim, aka Barbi, tells us.

[GScholz]

My all new (incomplete) conclusion:

The 109 G10/K4 did use C3 fuel in 1945, but it was rare because they could run on max boost with B4 fuel and MW50.

Originally posted by butch2k
The C3 stencil was applied on almost every G-10/K-4 because the DB 605DM was supposed to run on C3 to achieve the 1.75ata, exactly like the DB 605ASM.
 
BUT following shortage of C3, later revision of the motorenkarte, associated MW-50 documents and TA documents show B4 as a possible substitute fuel. The only restriction was not to cut MW-50 supply while running at a high boost because of detonation. And the aircraft were not repainted in any way.

Since C3 could sustain up to 2.2ata supply of MW-50 could be shutdown w/o any detrimental effects provided the pilot did not let the engine temp rise. Some testbed engine ran at 1.7ata with just C3 for instance.

Note that it was planned to up the DB605D max boost to 2.3ata with both C3 and MW-50.

I'm reading this as that the 109G10 and K4 could produce the same amount of boost with B4+MW50 as on C3+MW50 as long as MW50 supply was not shut off. This would mean that even with B4 fuel the 109G10/K4 could develop 2000 PS, but had to run on MW50 even at lower boost levels where the C3 would be sufficient alone.

Since C3 gave obvious advantages to cruising at high boost without using MW50, the C3 fuel was probably only given to the 109 units that were earmarked for high altitude combat in defence of the Reich.

Despite Isegrim's enthusiasm I don't think the 109G10/K4 was officially cleared for 1.98 ata boost until February 1945, I trust Butch2k's judgement on this.

[butch2k]

Attention here,

the DB605DM was cleared up to 1.75ata, the DB605DB pushed the limit up to 1.8ata, both could be sustained with use of either B4+MW-50 (as mentionned in various documents, even if it was an afterthought in the DM case) or C3-MW-50. However the DB605DC max boost at 1.98ata could be achieved with use of C3+MW-50 only.
 
Pushing the limit up to 2.3ata would have required a newer supercharger (DB603G model maybe) since you can see easily that it could not keep up with such a high boost as 1.98ata.

[GScholz]

Doh ... newly revised all new (incomplete) conclusion:

The 109G10/K4 were introduced in October/November 1944, but probably were not cleared for 1.98 ata boost until February 1945. Running on B4+MW50 the 109G10/K4 developed 1800 PS. Running on C3+MW50 it developed 2000 PS. Only a few 109 gruppen got C3 fuel, most likely those gruppen tasked with high altitude combat against US planes in the defence of the Reich in addition to a very limited number of other units (like those Butch2k mentioned in Luftflotte 6). The other 109 units had to rely on B4 fuel.

Now can we all agree on this?


Btw. Butch2k, how long until your books are available?

[VO101_Isegrim]

The Italian air force is not the German air force. You can't assume fuel deliveries were of the same type for the two air forces.

The ANR received planes from Germany (and from own Italian 109 production).
The German air force was responsible for providing all fuel types for the Italians (and other allied forces). The Italian supply situations is thus gives us some idea about the German fuel stocks, given the simple fact that a German Gruppe and the Italian Gruppo received fuel from the same source.

It's nothing to do with tech specs, it's to do with fuel availability, and the possibilities of supply to the airfields.

Italian airfields were supplied with German fuel types from German stocks. The fact that the Italians, who`s supply was undoubtfully the lowest priority to the Germans, received mostly C-3 fuel. I wonder if C-3 was so rare, why would the Germans give Italian units a priority over their own units... especially if the ANR`s planes didn`t neccesarily require it.

Ignore it if you want, the fact remains : large quantities of C-3 were supplied from German stocks in 1944/45 to units of tertiary priority on the German supply list.


I don't ha ve a date for the doc, if I did I would have posted it. BTW, are you claiming that the fuel situation improved for the Luftwaffe between Nov 44 and the end of the war?

I wonder how you arrived at that conclusion... certainly not from what I have written.

I have quoted German production figures to you before now, so I have obviously looked it up.

Obviously...


What did most bombers run on? B4? That would suggest less demand for B4 late in the war.

Doubtful. Tobak describes an incident when his G-6 mislanded on a German airfield, full of bombers. He had to argue to bomber`s commander, so that they would fill his plane with C-3 (instead of regular B-4 for the old DB 605A-1), as that was the only fuel type available on a bomber airfield. It would indicate that many bomber units were using it. Now, considering that a single He 111, for example, used up around 6 times of the fuel of a Bf 109s, and there were roughly equal number of bombers and 109s by late in the LW... an amount of C-3 supply in fact was freed up.

Given that most 190s required C3, and that few bombers were flying, what exactly were the Luftwaffe doing with the B4 if not using it in the 109s?

You see I also wonder where 150 grade went first. To the Spit IXs, the majority, which would be totally outclassed w/o it by 44/45, or the XIVs which were doing fine on 100 grade..?

I guess those few XIV Squadrons had to wait until all the MkIXs were filled up.


Remember the problem for the Lufwaffe was not just the amount of fuel, but getting that fuel to where it was needed.

I don`t see why one fuel type is harder to get to an airfield than and other. You tell me. Of course, they probably used up the remaining stocks, so units that already used C-3 - for their FW 190As, like JG 26 - probably converted earlier.


You say it's a half truth when I say it's the December edition, yet you repeat that the manual says "December edition".

You given only partial information regarding the date, which leads to a false image of the reality, unless corrected.

So let`s rehearse it again : you pointed towards that the manual is representative of the December 1944 state. It is not, as it is for early production planes, as in October.

To summerize, the K-4 manual of October shows an 1.8ata boost gauge, and tells nothing about the maximum MAP allowed.

The 3rd edition of the DB 605D`s manual of December 1944, mostl likely already valid in November 1944, explicitely says 1.98 ata MAP is cleared for the DB 605 D.
 

I used google totranslae it. Google says it's the December edition, which is what I called it.

It appears that Google also translated for you that it refers to the "condition as October 1944".

Question is, if you knew what date it is representative of, why did you told half the truth ? Forget it, it`s not really a question.


Sorry Isegrim, you are claiming 1.98ata was standard in December,

I don`t I just repeat the engine manual of November/December, which plainly says it was cleared to.

I posted details from a manual published in December showing 1.8ata was the max the boost guauge read up to. That's relevant.

You posted details of the October 1944 manual for the early K-4 with DB 605 DM engines.

The relevant is, that you manual you qoute is not showing the December 1944 conditions, but as of October 1944.

I doubt that you could not really get that a re-print of an old manual is still just a re-print.

The ENGINE`s OWN manual, again December edition, shows 1.98 ata is cleared. I tend to believe that more than how was the boost gauge in October..


If the Spitfire IX manual published in 1943 showed 15lbs boost, I'd consider it very relevant, and a good indication that 15lbs was all that was allowed. I am after all pointing to a manual published in December 44, not October.

Good, so since in 1942/43 the Spit IX with a specificwas not cleared for more than 15 lbs, it means it never was, not even it`s other engined variants.

Keep it repeating, Naswhan. Still, the manual you qouted shows the condition of October 1944 (and for the early planes only).
Do you actually say that if I take it print it out now, it will suddenly show the February 2004 conditions of the K-4...?

We don`t discuss what was it in October with the early planes, probably no more than a hundred out of the 1700 produced.

And the day of publication is listed as:

Rechlin, den 29. Dezember 1944

Irrevelant when it was published, as it shows the conditions of October 1944, not December.

You try to argue that it shows the December conditions, when it`s cleared stated:

"October 1944 condition"

quote:
--------------------------------------------------------------------------------
Where did you take 1.42ata was cleared in the beginning of service? I tell you, nowhere, it`s an assumption, made up by you to support your other assumptions. Sandcastle built on sand...
--------------------------------------------------------------------------------


You only forget one thing : answering the question..
From where did you take it was cleared for service when it entered service ?

You did not answer that, rather you given us more of your assumptions. Which means you only assumed things, to back up your other assumptions.

That`s a sandcastle builts on sand. You keep repeating your own mythology, and refer to yourself in order to prove it.

[Angus]

For what it's worth, fuel supply to the Axis airforces was a big problem in the later half of the war.
Otherwise they wouldn't have been using oxen to pull their planes about

[butch2k]

The K-4 manual is quite clear Isegrim about the max boost available on the DM engine :
"Die Entnahme der sondernotleistung geschieht durch vorschieben des lestunghebels auf 1.75ata ladedruck." etc...

AS for the 1.8ata boost the document i have coming from DB addressed to various institution clear the use of 1.8ata on the DB605DB and is dated 24 January 1945. And also mentions that test of 1.98ata could now begin.

[MiloMorai]

Some posters here should read this

http://www.angelfire.com/super/ussbs/index.html

notice that the actual production of avgas was almost nil by mid March





Table 14 is of some interest as well, with the total supply in 1944(1,105,000) almost 1/2 of the total supply in 1943(1,917,000). In fact, 1944 was even less than 1942.

[VO101_Isegrim]

Isegrim, you don't seem to understand the point. The 109G2 was supposed to use 1.42 ata.

According to you. Proof...? No...

Manuals can be superceeded. Wether the G2 manual was superceeded, or wether it hadn't yet been published, is immaterial, the G2 was derated from it's expected 1.42ata to 1.3ata.

According to you, again. Proof...? No... Parrotting it madly won`t change that.
There`s no single document that would state the G-2 was downrated. The DB 605A itself had early problems, from earlier on, and the G-2 that came well after the introduction of the DB 605A, was of course running on the maximum boost allowed to it`s engine at the time of introduction.


No, the Merlin III was designed for 6.25 lbs, and had it's rating increased to 12 lbs in service. Can you find some documents showing it was originally intended for 12 lbs boost?

I didn`t say it was originally intended. It was intended later on, and the attempt had to be recalled becuse of engines that failed.


No, the Merlin 61 was designed for 15lbs boost. Later 60 series engines increased it.

= Merlin 61 engines failed to increase boost rates because of technical problems.

Isegrim, it's easy to find references like the G2 at 1.42ata, the 190A4 at 1.45 ata, and references to them being downrated.

Show me those references of them being downrated. Show me a reference that explicitely say the G-2 is downrated. So far you have come up with NONE, just parrot it.

I am especially interested for the FW 190 A-4 at 1.45 ata. Never heard of such boost cleared for the BMW 801D. Besides, in case of the FW 190A-3 and A-4, the problem was not with the engine, but with the airframe (the new BMW engine generated more power and heat than the engine mount was designed to handle. ) The solution was modifing the airframe to allow for better cooling, not the engine.

Where are your references to the the Spit I being downrated, or the Merlin 61 being downrated to 15lbs?

The British attempted the use +12 lbs as a WEP. It overstressed the engine greatly, and it`s use has to be restricted to emergency use only. The reference can be found on the fourthfightergroup website. Fact is the engine could not take the stress they wanted from it.

Another example is the Merlin 266. They attempted to clear it for +25 lbs, but they failed, and the engine was soon needed to be DOWNRATED to +21 lbs.

Another : Griffon 65. They attempted +25 lbs with 150 Octane in early summer 1944. Sever main bearing troubles occured, then engine was again DOWNRATED to +21 lbs.



Should I mention the Vulture, the Sabre, too ? British engines had reliability problems throughout the war with the new, higher boosts.

All I can find, even in the earliest Spit tests, are references to lower boosts that get increased as the war progresses. The opposite is true of some German engines.

Rather laughable claim. German engines being downrated during the war? Oh, yeah, sure let`s look on the example of the DB 605A series, your favourite :

1942 : 1.3 ata, 1310 PS
1943 : 1.42 ata, 1475 PS
1944 : 1.7 ata, 1800 PS
1945 : 1.98ata, 2000 PS

The same engine, with small modifications, increased power output by 700 HP in 3 years.

The opposite is true for some British engines. The Merlin 266, for example, had to be derated in 1944 because of timing problems.

Isegrim, more than 18lbs required 150 octane. The Griffon 65 was in production long before 150 octane was. It was designed for 18lbs boost, and increased to at least 21 lbs. Can you find a reference to the Griffon 65 at 25 lbs?  

Not at all in Squadron service, nobody can in fact. There attempts to allow for +25 lbs. All failed. They had to derate it to +21 lbs.


No, Isegrim, the difference is there's a Spitfire XIV chart showing 397 mph at sea level, but you want to discount it because you don't know wether the Griffon 65 could use 25lbs boost.

You version. Actually, nobody ever seen anything that would imply the Griffon 65 was ever cleared to +25 lbs in service. Not even Mike Williams, who put on that test on his site (but somehow failed to mention this part).

The best figure available for the K4 at sea level is 377 mph, and you persist in using that despite very little info about the conditions it was achieved under, and wether it was actually used in combat, certainly Butch is implying it was rare.

So far in this thread, the only person who claims 1.98ata was not used in combat is you, and you can`t prove it, nor back it up.


The best figure for the Spit XIV is 396 mph at sea level, but you want to discount it because you don't know how common it was in real life.

I, and everybody else here, including Neil Stirling, says this was a single test and such plane was never seen in operational service. Not that I don`t know how common was it, on the contrary. I KNOW it wasn`t used AT ALL.


See the hipocrisy? There's another Spit XIV figure of 387 mph at sea level, but you want to ignore that as well.

Which is again at +25lbs, for which the XIV was NEVER cleared. Why use figures like this? Unlike the 109 K-4, which WAS cleared for 1.98ata, according to everyone (maybe except you), the only question is WHEN, within a few months period.

My figures show a conditon that appeared in real life, your ones show ones that never did.


You have a single document for the 109, which shows 377mph, and you accept it as gospel, you have a doc that shows 396 mph for the Spitfire, another that shows 389 mph, and you accept 358 mph. That's hipocracy, Isegrim.

No, that`s reality. 389 and 396mph are for a plane that was running in a single test, in stripped condition, on a boost it never used in real life. There`s however a test that shows the XIV under it`s normal boost pressure, for 358 mph (BTW, I could also use 352 mph - that was what was measured on XIVs taken from operational squadrons). Of course under +21boost, the highest boost it used, it would be slightly faster, I would expect about 370 mph, as fast as the K-4 on it`s lowest boost.


Sorry Isegrim, the highest speed for a Spit XIV at sea level is 397 mph. http://www.fourthfightergroup.com/eagles/spit14pt.html

I accept that might be slightly faster than normal service use, it's probably for a clipped wing aircraft without a mirror, which is why the supply ministry list 389 mph at sea level.  

It`s for a boost that was never cleared for operational used, and never appeared in combat. Unlike the K-4 at 1.98ata.

[VO101_Isegrim]

Originally posted by butch2k
The K-4 manual is quite clear Isegrim about the max boost available on the DM engine :
"Die Entnahme der sondernotleistung geschieht durch vorschieben des lestunghebels auf 1.75ata ladedruck." etc...


I have never argued about the DM, butch. But it`s a bit of irritating as Nashwan clearly wants to sell the October 1944 manual for 605 DM equipped K-4s as valid for the DB and DC as well, for later periods. Why not bring up an E-3 manual right away...


AS for the 1.8ata boost the document i have coming from DB addressed to various institution clear the use of 1.8ata on the DB605DB and is dated 24 January 1945. And also mentions that test of 1.98ata could now begin.

What about the december DB 605 D manual Chris referred to ?
It says 1.98 ata cleared,  December and probably earlierm doesn`t it ? Heck, anyway I look on that fact, it can`t be understood in any other way than what it says.

[VO101_Isegrim]

German Avgas production, stocks, and consumption.

Points of interests:

1, From Summer 1944 onwards, when most bomber units were grounded, there was a great decrease in consumption until about September-October, by when only fighters and such lighter a/c were flying.

2a, From about May 1944, German avgas production was down, they effectively living up the large reserve stocks accumulated during 1943.

2b, Safely can be said, actual production of avgas thus had little effect on the availability of fuel times, it was dependent on what was available in the stocks.

3, By November 1944, the pressure on the oil plants eased somewhat, production was again able to meet the demand for a short period. As the bombings renewed, and territories were lost in 1945, production steadily fall.

4, Avgas consumption even during late 1944, was considerable at 50 000 tons/month, mostly used by fighters. Comparision can be made with Allied fighter fuel consumptions.

5, The decrease of stocks and production, at the same consumption rate, would mean that the LW would be grounded by May in any case.

[butch2k]

The G-2 was definitely derated
one example among a lot of others...

[mw]

Hiya Butch2k, I've been puzzeled for some time as to the following: Vorläufig gesperrt nach VT-Anweisung Nr.2206
(Provisionally closed after VT instruction Nr.2206)

What is this Nr.2206 document/order?  Do you have it?  I'm wondering if its related to R.L.M. message GL/C-TT No.1374/42/42 of 12.6.42.