Is the Spitfire Really Superior to the FW-190 ... continued

[Gille]

Honestly I doubt you can even read a word of those German articles, either that or you are a bit nutty to be denying the plain language of them.

But lets see - if you really can read German and that article, a little quiz:

- what modification to the 801D is discussed as producing a +80PS improvement in power, why wasn't it implemented and what did they decide to do about that potential modification instead?

[Gille]

Hmmm...you can read an entire six page technical article in German in 35 minutes well enough to understand it completely and dismiss the author as wrong, but you can't translate four sentences in 25 minutes?

[the lancaster kicks ass]

or maybe he's not online at the moment??

[vanir]

You're right, I use a translator program and my own engineering knowledge to gloss over technical data and graph/blueprint. None of which display the "special C3-injection system" described in this thread.

The paragraph you refer to (on page 1 of the document) appears to be discussing the use of twin pressure relief valves for the two-speed supercharger in the BMW 801 which sacrificed some 80hp and caused reliability issues, discovered as a result of testing in 1942.


Could you please point out the paragraph which refers to this "special C3-injection system" ? I'd really like to read about something which has no engineering blueprints, cannot be found on any surviving engines nor technical renditions of the 801D and is challenged by every technical examination of this engine around the world.
Where is the part about the injectors mounted at the engine air intake?
Where is the differentiation between this injection system and any other sequential injection system on BMW series engines?
Where is the part where it was offered as an alternative to MW-50 engines which also used C3 fuel?

[Gille]

The paragraph you refer to (on page 1 of the document) appears to be discussing the use of twin pressure relief valves for the two-speed supercharger in the BMW 801 which sacrificed some 80hp and caused reliability issues, discovered as a result of testing in 1942.

Close but not really, which just goes to show the limitations of electronic translation programs.

What that para (under the heading Doppel oder Einzeldusen) is talking about is a trial replacing the double exhaust pipes with a single pipe, producing an 80PS boost. On 16 March 1943 Rechlin advise Focke Wulf that the tests on this modification are succcessful and that it should be implemented however Focke Wulf decide not to changeover but instead apply the change to the 801E engine.

I'm not a native speaker but here's my best effort at summaring the rest of the article:

The para headed Versuch bei der E-Stelle Rechlin talks about the trials with the C-3 injection - (C-3 Einsitzsprung), basically what it says is:

- 6 190s were used for trials starting 17 May 1943 and finishing in July 1943

- the engines were run at 2700/1.65ata with the C3 injection activated

- in all 32 hours of tests were done on the 6 machines

- power output at ground level was 2060PS

- speed gain ranged from 30 to 45kph depending on how the aircraft was configured

The table at the bottom of that page shows the results obtained for the six aircraft with the C3-Einsitzprung.

The article goes on to talk about engine temperatures and notes that two aircraft were run at 1.65ata even without the system running, but that for combat the system should be used.

The section after that talks about tests from 3 June 1943 by Focke Wulf on a A-5/U8 which obtained a speed boost of +37kmh at 200 meters altitude.

There is then a discussion about the tests done with the MW-50 system, these however only produce a boost of +16kph.

There is then a discussion about the C-3 system being fitted to operational F and G jabo's and the limitations on its use - only to be used under 1000 meters with the supercharger in first gear.

The most interesting section is the last. Basically it says that from July 1944 all A-8s got the C-3 injection system and that it could be operated without altitude restriction with earlier aircraft being able to be upgraded.

It says that in first supercharger gear the engine could be run at 1.58ata and in second at 1.65ata. The gain is speed was 22kph in first gear, 25kph in second and it could be run for ten minutes. The system could be used up to the rated altitude.

I'm sure one of the native speakers could do a far more polished and comprehensive job.

[vanir]

I'd like also to apolegise for using the notably personal reference, "twit" in one of my above posts. It was wrong and I shouldn't have done it.
And secondly what I should have said and was rightly called out on, was that I'd glossed over the documents relying upon my personal knowledge of motor engineering, particularly the technical data, graphs and blueprints and found no evidence of what has been described in this thread, the "special C3-injection system delivering fuel into the air intake" of the BMW 801D-series engine used by Fw-190s in the documents presented. I maintain that anyone can be simply incorrect however I do not believe so in this case, as both my personal knowledge of high performance systems and quite a bit of research in the last few days coincide for me to conclude.

Those two points are a character failing and I do not wish them to detract from discovering the truth in this matter.

Everything I have researched supports my own personal experience and directly challenges that which has been suggested. Nothing so far corroberates these illogical claims in a clear and credible fashion and they appear to me to be myth based on misinterpretation and a lack of intimate knowledge of fuel delivery systems in high performance applications.

I am however, as I have always been determined to remain open to clearly stated presentations by credible sources. If anyone has any related documentation which is easily translated, or can point out those sections to be translated, or renditions in english and most notably and preferrably, any technical blueprints or similarly clear renditions of this magical air intake injection system of C3 fuel used on any radial engined Fw-190 I would be highly appreciative.
Considering the nature of the claim it must be clearly stated it is a C3 injection system and not being confused with any MW-50 installation, which is indeed at the supercharger discharge piping and may be loosely termed as within the air intake for the engine.

Should anyone manage to assist in the matter, I thankyou in advance for your time.

[KraziKanuK]

I've looked up every link you've posted and am still yet to see this fabled "special C3-injection system" which "injects fuel into the left air intake to provide additional cooling and prevent predetonation" in any of them.

Would you like to comment on this oh one of such great 801 knowledge?

C3 kraftstoffzusatz einspritzanlage = C3 fuel additive fuel injection system

C3 zusatzeinspritzung = C3 auxiliary injection

This is from the upper right corner of the 2cd link Gille posted. Note that #8 is the port intake. Also note that #3 is labeled einspritzdüse, ie. injector.

So you read all the links Gille posted? You need to get some better reading glasses.

Do you know what the bulges on each side of the cowling were for. Let me tell you. They were the dual intake ducts that led to the supercharger.

If the 'C3 injection' was not used, why was a yellow ring, a 150mm od dia, 10mm wide, placed on the rear left corner of the fuselage armament cover. Strange that the A-8 manual would mention such a marking for something you says does not exist.

As for Crumpp. He is part of White 1 and has a collection of 1000s of pages of original documents on the Fw190.

[vanir]

If you're using machine translation then you must have typed pretty quick to get that whole article in in only half an hour and translated, you did claim that you had read it.

The paragraph you refer to (on page 1 of the document) appears to be discussing the use of twin pressure relief valves for the two-speed supercharger in the BMW 801 which sacrificed some 80hp and caused reliability issues, discovered as a result of testing in 1942.

Close but not really, which just goes to show the limitations of electronic translation programs.

What that para (under the heading Doppel oder Einzeldusen) is talking about is a trial replacing the double exhaust pipes with a single pipe, producing an 80PS boost. On 16 March 1943 Rechlin advise Focke Wulf that the tests on this modification are succcessful and that it should be implemented however Focke Wulf decide not to changeover but instead apply the change to the 801E engine.

I'm not a native speaker but here's my best effort at summaring the rest of the article:

The para headed Versuch bei der E-Stelle Rechlin talks about the trials with the C-3 injection - (C-3 Einsitzsprung), basically what it says is:

- 6 190s were used for trials starting 17 May 1943 and finishing in July 1943

- the engines were run at 2700/1.65ata with the C3 injection activated

- in all 32 hours of tests were done on the 6 machines

- power output at ground level was 2060PS

- speed gain ranged from 30 to 45kph depending on how the aircraft was configured

The table at the bottom of that page shows the results obtained for the six aircraft with the C3-Einsitzprung.

The article goes on to talk about engine temperatures and notes that two aircraft were run at 1.65ata even without the system running, but that for combat the system should be used.

The section after that talks about tests from 3 June 1943 by Focke Wulf on a A-5/U8 which obtained a speed boost of +37kmh at 200 meters altitude.

There is then a discussion about the tests done with the MW-50 system, these however only produce a boost of +16kph.

There is then a discussion about the C-3 system being fitted to operational F and G jabo's and the limitations on its use - only to be used under 1000 meters with the supercharger in first gear.

The most interesting section is the last. Basically it says that from July 1944 all A-8s got the C-3 injection system and that it could be operated without altitude restriction with earlier aircraft being able to be upgraded.

It says that in first supercharger gear the engine could be run at 1.58ata and in second at 1.65ata. The gain is speed was 22kph in first gear, 25kph in second and it could be run for ten minutes. The system could be used up to the rated altitude.

I'm sure one of the native speakers could do a far more polished and comprehensive job.

I still think the claims made in the thread, the essence of your assertion is a complete misinterpretation, because it doesn't make engineering sense. Everything in my experience has made engineering sense or has been incorrect.
I shall have to gain some proper interpretation of the sections you've pointed out and get to the matter of this "special C3-injection" as opposed to normal 801 series M4 injection. I suspect it will again specify nothing more than fuel octane and tuning alterations without the addition of extra fuel injectors most certainly not in the engine air intake.

In the meantime, could you sparkle me and describe how this system works in one series of paragraphs. I apolegise if I'm asking you to cover old ground however I just have a sense of humour for hearing things that don't add up extrapolated.

Start with the C3-fuel injectors in the left engine air intake again and follow it through how this cools the air intake charge coming out the supercharger...

[Gille]

The diagrams on the second page of the article are from the Flugzeug Handbuchs and show the layout of the system.

As to how it works, I'm not an aircraft engine guru but AFAIK it works pretty much the same way as MW-50 except that fuel is used as the coolant instead of a methanol-water mixture. With MW-50 the mixture is sprayed on the fuel/air charge so as to reduce the temperature of that charge (by evaporation of the water, the methanol is just there as an anti-freeze) and thus to prevent detonation in the cylinders prior to proper combustion. This lets you run the supercharger on higher boosts that would otherwise be possible without detonation.

C3 injection works the same way except that fuel is used instead of MW-50. If an aircraft can be configured with MW-50 injection I don't see what is so hard about conceiving the same system save that you use fuel instead of a special mixture, its easier to set up because you don't need the special MW-50 tank.

I'm sure if MW-50 worked better in the 801D then the Germans would have used it, but their testing showed the C3 injection allowed higher boosts and gave greater speed.

[vanir]

The diagrams on the second page of the article are from the Flugzeug Handbuchs and show the layout of the system.

As to how it works, I'm not an aircraft engine guru but AFAIK it works pretty much the same way as MW-50 except that fuel is used as the coolant instead of a methanol-water mixture. With MW-50 the mixture is sprayed on the fuel/air charge so as to reduce the temperature of that charge (by evaporation of the water, the methanol is just there as an anti-freeze) and thus to prevent detonation in the cylinders prior to proper combustion. This lets you run the supercharger on higher boosts that would otherwise be possible without detonation.

C3 injection works the same way except that fuel is used instead of MW-50. If an aircraft can be configured with MW-50 injection I don't see what is so hard about conceiving the same system save that you use fuel instead of a special mixture, its easier to set up because you don't need the special MW-50 tank.

I'm sure if MW-50 worked better in the 801D then the Germans would have used it, but their testing showed the C3 injection allowed higher boosts and gave greater speed.

This has been my whole problem from the start. Fuel doesn't do that.
Look up any supercharger site on the Web, navigate to centrifugal supercharger intake cooling and read.
There's whole engineering curriculums based on this. They're all wrong, you can't describe specificaly how this system works (perhaps there is some additional system added on C3 injected Fw-190's as an alternative MW-50 style option, hell I don't know), but the one you described does not work in the way you describe.

Either
a) your idea of how this additional system on C3-injected Fw-190's which is not MW-50 works is not accurate
b) the idea that a seperate system on C3-injected Fw-190's which is not used on regular C3-burning Fw-190's nor those fitted with MW-50, is itself inaccurate, caused by a misinterpretation of documents

Either satisfies me as either has been what I've said all along.

It is essential that a suitable presentation of describing the operation of this system is posted for it to be understood. If it is not understood, it could be something other than what is being assumed by some and challenged by me (and every independant, credible web source I can find).

I shall continue searching the web for any suitable documentation, look up any suitably authoritive translations of the documents you've provided and suspend a resounding apolegy for a genuine and clearly specified conclusion.

[Nonskimmer]

Guys, this is fascinating. I haven't seen a thread become this technically in-depth in ages.
Just don't freak-out if someone a little less well versed in C3 injection systems (me, for example ) tries to get a word in somewhere, eh? Thanks guys.

Nice info by the way.

[vanir]

Well after much searching I finally found this fabled "special C3-injection system."
From the University of Western Ohio:

The Fw 190F-8 was powered by a BMW 801 D-2 engine variant adapted for C3 (96 octane) fuel. An additional injector in the left supercharger inlet for emergency short term (10-15 min) engine power increase during flight under 1000 m altitude was standard equipment.

No wonder I couldn't find it, it was used only on the ground attack F-8 variant Fw190 and is a completely different engine setup to that used on the fighter types from A-3 through to A-9. Obviously it appears on no blueprints or documentation for these aircraft. It is not the C3 injection system at all (all BMW801D-2's used C3 fuel and were sequentially or multipoint, direct injected), it is the boost-system used on that, low-altitude model. C3 fuel was used on all Fw-190's from the A-3 onwards due to higher compression ratios and supercharger gearing. All my source materiel has been accurate on this matter.

Now back to the point. The F-8 boost system does not work at all like MW-50 injection.
Far from providing additional charge cooling, the single injector richened the mixture to prevent detonation, which allowed the use of higher boost pressures selected or modified on the variable automatic boost regulator fitted to the standard Fw-190 engine management.
Higher boost settings is what is in fact increasing the power output. Taking it out of optimum fuel-air mixture ratio combined with the use of higher boost rating at emergency power, to prevent predetonation, in effect gaining more than you lose. It is a retuning of the engine and does not work anything like water-injection save that the engine still runs on its normal fuel injectors for its primary fuel flow. Now it has a tiny increase in fuel flow elsewhere in the system.
The plumbing is different, as the MW-50 was placed in the supercharger discharge piping where it would cool intake charge on the compressor outlet where it counts. And of course the F-8 boost system drew from the fuel pump.

It is the equivalent of pouring a little fuel down the throat of a carburettor to get it started after having run dry. Instant rich mixture. It cannot alone increase engine horsepower without other tuning alterations, unless the engine was already out of tune and running leaner than optimum to begin with. In fact the engine would produce more power without the secondary fuel richening but with the additional boost, although the engine would quickly fail due to predetonation.

Which takes me back to my original post. C3 fuel (ie. high octane fuel) does not lower cylinder temperatures, it simply burns at a higher one. No matter where in the system you introduce it (other than right next to the cylinders). I'll even add a bit, which I already explained in the first place, richer mixture burns at higher temperatures than a leaner one, but starts to take your engine out of tune. If your Fw190 is overheating coming in for a landing and starts to splutter, you richen it up so it won't stall when you suddenly open the throttle and go for a flyaround.
Water injection lowers cylinder temperatures.

An important stipulation, all fighter variants from the Fw190A-3 already used C3 and no additional fuel injectors. From the same source regarding the A-3:

Beginning in the spring of 1942, series production of a more powerful engine version BMW 801D-2 that replaced previous versions in the Fw 190Fighter created a new plane version designated as Fw 190A-3. The increase in the BMW 801D-2 engine power (to 1730 kW) was due to a higher compression ratio and higher pressure two-speed compressor. A higher compression ratio and charging pressure made it necessary to use high-octane (96 octane) C3 fuel in place of B4 (87 octane) fuel.

This is the run of the mill, basic engine fitted to all fighter models from the A-3 onwards, without boost.
And the A-8 which sported the boosting system fitted standard on fighter variants:

A new model with different equipment. Most important were parts of the MW 50 injection system, used for short term engine power boost. A cylindrical tank of 118 liters capacity was mounted in the rear fuselage. In an emergency, it could be used as additional fuel tank. Tank installation shifted the center of gravity backward and, as a cure, the under-fuselage mounted ETC 501 bomb rack was moved 20 cm forward. This rack became a standard from the A-8 model.

And this booster system was usable under a wider variety of atmospheric-densities, because it cooled the cylinders to prevent predetonation at higher settings, which the F-8 low-altitude booster system did not. It altered the engine tuning.

[evangilder]

You could have left it at the facts and known that you presented things well. To me, you spoiled it with your last paragraph. The info was great, but remember that it is the last thing you said that will be freshest in ones mind.

[vanir]

Fair enough. Edited to remove. I apolegise.

[evangilder]

No problem, it's always a learning experience. You presented a good case. Thats' all you need and that should also satisy the detractors. Great info, by the way!