Thoughts on the K-4 Manouverability

[Bremspropeller]

On 8/19/2021 at 5:31 PM, III/JG52_Otto_-I- said:

You missed the phrase... and Wernher von Braun never work for NASA  

 

Yeah, designing stuff. The rockets and their components were built by aerospace contactors, such as McDonnell, North American Aviation, Convair, Boeing, etc.

 

Good luck catching that piece of information and coming back full circle to "Thoughts on the K-4 maneuverability"...

[III/JG52_Otto_-I-]

On 9/14/2021 at 11:10 AM, Bremspropeller said:

Yeah, designing stuff. The rockets and their components were built by aerospace contactors

  So you are agree with @gimpy117 in the pharse "So the idea that german build quality continued in my experience is pure self serving fantasy" ??

Designing stuff is the matter, ..The first step of a good quality product, is a good desing.

 

On 9/14/2021 at 11:10 AM, Bremspropeller said:

Good luck catching that piece of information and coming back full circle to "Thoughts on the K-4 maneuverability"...

Read your last posts, prior to any criticism about off-topic posts of other users. By the way, thanks for help me to teaching here a bit about technical progress of German aerospace engineering during WWII.

Edited September 16, 2021 by III/JG52_Otto_-I-

[gimpy117]

On 9/16/2021 at 11:16 AM, III/JG52_Otto_-I- said:

  So you are agree with @gimpy117 in the pharse "So the idea that german build quality continued in my experience is pure self serving fantasy" ??

Designing stuff is the matter, ..The first step of a good quality product, is a good desing.

 design was never the question with late war 109's, rather if the late war German industry is equipped to actually produce said designs to a quality standard that could perform to the calculated values the designers set forth. 

[LLv34_Flanker]

S! 

 

Even it is anecdotal information, a JG 52 pilot(have his book, must dig up the name) preferred his G-10 made by Erla over the K-4. He could even give Werke numbers of them. Those Erla built 109's were of better quality and finish. Same applied to 190's made in Cottbus. 

 

There was also info that the geometry of elevator linkage was different on K-4 than G-6 for example. A heated debate ensued "on the other sim forums", but there were drawings/blueprints verifying this. Could affect the handling positively. 

 

The common mantra seems to be that K-4 must be a pig. Like the FW190. It had improvements to handling, aerodynamics etc. over G-series. It was a little heavier but again had nearly 325hp more than G-series, 1475hp vs 1800hp. 

 

Maybe it was not as nimble as the F-4 but it beat it in speed and climb without a contest, while still retaining good handling. Same applied to Spitfire as well, Mk.IX was considered by many as the last true dogfighter while Mk. XIV and later were of different breed. Not as nimble but better in other ways. 

[CUJO_1970]

On 9/21/2021 at 5:30 PM, LLv34_Flanker said:

S! 

Even it is anecdotal information, a JG 52 pilot(have his book, must dig up the name) preferred his G-10 made by Erla over the K-4. He could even give Werke numbers of them. Those Erla built 109's were of better quality and finish. Same applied to 190's made in Cottbus. 

 

 

Peter Duttmann?

 

“With the auxiliary MW-50 installation in my Bf 109 G-10 in which I flew till the end of the war, I was able to save myself in all of the prickliest situations, of which there were several in April 1945. When no methanol was at hand, we used distilled water which functioned just as well, except that we were no able to fly high, otherwise the whole installation froze. In the sorties we flew short before the end of the war in low-level flight in the Cham area and east of Regensburg, we often met US fighters, and although they were superior to us in numerical terms, we were able to get away from them. The fastest Bf 109 I ever flew in, I handed it over to the Americans on 8 May 1945 in Neubiberg”

[LLv34_Flanker]

S! 

 

Thanks, Duttmann it was

[gimpy117]

On 9/22/2021 at 11:03 PM, CUJO_1970 said:

 

Peter Duttmann?

 

“With the auxiliary MW-50 installation in my Bf 109 G-10 in which I flew till the end of the war, I was able to save myself in all of the prickliest situations, of which there were several in April 1945. When no methanol was at hand, we used distilled water which functioned just as well, except that we were no able to fly high, otherwise the whole installation froze. In the sorties we flew short before the end of the war in low-level flight in the Cham area and east of Regensburg, we often met US fighters, and although they were superior to us in numerical terms, we were able to get away from them. The fastest Bf 109 I ever flew in, I handed it over to the Americans on 8 May 1945 in Neubiberg”

that's kind of dubious. so he says they're just porting water in the engines? no methanol?  

[bzc3lk]

1 hour ago, gimpy117 said:

that's kind of dubious. so he says they're just porting water in the engines? no methanol?  

 

Water will achieve the same desired result except unlike methanol will freeze at higher altitudes as outlined in his statement. See the clip below showing how BMW used water injection to minimize the effects of knocking allowing them to increase the boost. German methanol production had drastically declined by 1945, so water injection may have become the next best option.

http://www.wwiiaircraftperformance.org/Methanol.pdf

 

 

[gimpy117]

13 hours ago, bzc3lk said:

 

Water will achieve the same desired result except unlike methanol will freeze at higher altitudes as outlined in his statement. See the clip below showing how BMW used water injection to minimize the effects of knocking allowing them to increase the boost. German methanol production had drastically declined by 1945, so water injection may have become the next best option.

http://www.wwiiaircraftperformance.org/Methanol.pdf

 

 

of course it keeps knocking down, but without methanol what's the performance gap between one without? I'd like to see data on this. I guess just water would keep the engine from going kaboom. I suppose it would come down to just how "just the same" it is with just water, that's what made me question it. 

[HR_Zunzun]

What I thought is that the methanol only lowered the freezing point but the water alone was better in the antiknocking propierties.

[JtD]

Yes, that's how it is Zunzun. Another point is that Methanol is also used up in the combustion, which pure water obviously isn't. You'd be running a leaner mixture with no ill effect due to the extra cooling by the extra water.

 

On the bottom line swapping water and MW50 makes marginal differences to the engine performance, if that is all you do. You could adjust injections, timing and boost to the change, that would result in a noticable differece, but that's nothing you do in the field on the fly.

[ZachariasX]

I might add that having lots of methanol (Germany) compared to little (Allies) was mostly due to the Aliied engines being able to fully exploit the high octane fuels and were running at their structural limit anyway, hence you only used water to lower CH temps and give some more headroom for added power. German engines, especially the DB ones had to be operated below what they were theoretically capable and thus were essentially de-rated engines for the most part. Increasing the methanol fraction from a fraction that just serves to prevent freezing at altitude (as the Allies did), the Germans added methanol to a degree where it becomes a significant part of the fuel to make up for some of that limitation.

 

Hence, if you were to use just water and C3 as "bi-fuel", you would be slighty restricted in power output as the DB engine arangement could provide. Then again, since only low level flying is possible, I guess you wouldn't see that gap in performance.

[Kurfurst]

On 9/26/2021 at 6:08 AM, gimpy117 said:

that's kind of dubious. so he says they're just porting water in the engines? no methanol?  

 

The official MW instruction for G14 says use C3 and MW50 wherever possible. If C3 is not available for any reason, it can be substituated with B4 just beware never to use emergency power with it but sans MW50 engaged as it will immidiately destroys the engine due to knocking.

 

Instead of MW 50, MW 30 (30% methanol), EW 50 or EW 30 (with ethanol, so basically the good stuff) or as a last resort, pure tap water may be used.

 

Water was the main agent i charge cooling, (m)ethanol was just anti freeze for the most part with far less energy content as fuel, than, well, actual fuel.

 

I guess methanol was preferred for two reasons - one, its a dirt cheap chemical industry base product. Second, it must not be drinked as it will blind and/or kill you, and thats a probably a good thing with lots of soldiers around.. 

[gimpy117]

6 hours ago, VO101Kurfurst said:

I guess methanol was preferred for two reasons - one, its a dirt cheap chemical industry base product. Second, it must not be drinked as it will blind and/or kill you, and thats a probably a good thing with lots of soldiers around.. 

evaporation in the intake also cools the air charge, so it helps cool hot turbo/supercharger to increase power with a denser charge (but thats mainly water), Methanol also increases octane rating but running water only would be inferior, as you would not make as much extra power. I don't think freezing has as much to do with it, rather losing the properties of the methanol. you can run the engine at a higher boost sure, but actual power will be lessened vs with methanol (probably at any altitude?)  

Edited September 28, 2021 by gimpy117

[41Sqn_Skipper]

8 hours ago, VO101Kurfurst said:

 

Instead of MW 50, MW 30 (30% methanol), EW 50 or EW 30 (with ethanol, so basically the good stuff) or as a last resort, pure tap water may be used.

 

Water was the main agent i charge cooling, (m)ethanol was just anti freeze for the most part with far less energy content as fuel, than, well, actual fuel.

 

I guess methanol was preferred for two reasons - one, its a dirt cheap chemical industry base product. Second, it must not be drinked as it will blind and/or kill you, and thats a probably a good thing with lots of soldiers around.. 

 

L. Dv. T. 2109 G-14/Fl
MW-Anlage-Karte
Stand Oktober 1944

 

doesn't mention the use of pure water or ethanol. It only mentions MW 50 or MW 30. What exactly is your source?

 

When pure water is used, was the 0.5% anti-corrosion oil still necessary?

 

Edit: 

According to http://www.wwiiaircraftperformance.org/me109/Me-109K4-handbook-1-75.jpg the use of "EW 50 (Dethanol-Wasser 50:50)" instead of MW 50 and MW 30 is possible. EW 30 is not mentioned. 

Edited September 28, 2021 by 41Sqn_Skipper

[Cpt_Siddy]

On 9/26/2021 at 11:25 PM, HR_Zunzun said:

What I thought is that the methanol only lowered the freezing point but the water alone was better in the antiknocking propierties.

 Latent heat of fusion for methanol 3.1773 kJ/mol

vs water at 6.01 kJ/mol

 

So water is 2x/mol better at absorbing heat from the charge air.

 

 

Edited September 28, 2021 by Cpt_Siddy

[III/JG52_Otto_-I-]

On 9/28/2021 at 6:08 AM, gimpy117 said:

but running water only would be inferior, as you would not make as much extra power

 

On 9/28/2021 at 6:08 AM, gimpy117 said:

I don't think freezing has as much to do with it, rather losing the properties of the methanol.

For an aircraft mechanic, I see you very low in aircraft engines knowledge..  .. I am ashamed to read certain comments from a colleague.  
please, read the P-47 Manual 



By the way, the system was copied from Germans too.  

Edited September 29, 2021 by III/JG52_Otto_-I-

[Legioneod]

1 hour ago, III/JG52_Otto_-I- said:

 

For an aircraft mechanic, I see you very low in aircraft engines knowledge..  .. I am ashamed to read certain comments from a colleague.  
please, read the P-47 Manual 



By the way, the system was copied from Germans too.  

I guess the Germans really were the superior race. Seems like the Allies stole all of their ideas without ever coming up with anything for themselves.

Shame the Germans lost.

[357th_Dog]

3 hours ago, III/JG52_Otto_-I- said:

 

For an aircraft mechanic, I see you very low in aircraft engines knowledge..  .. I am ashamed to read certain comments from a colleague.  
please, read the P-47 Manual 



By the way, the system was copied from Germans too.  

Interesting, I wasn't aware that Sir Harry Ricardo, who invented water-methanol injection to boost the performance of internal combustion engines, was German. 

[gimpy117]

4 hours ago, III/JG52_Otto_-I- said:

 

For an aircraft mechanic, I see you very low in aircraft engines knowledge..  .. I am ashamed to read certain comments from a colleague.  
please, read the P-47 Manual 



By the way, the system was copied from Germans too.  

"though commonly referred to as water, the solution actually used is a mixture of water and alcohol" 

it would seem that late war, the only ones running pure water were the Germans, out of a shortage of methanol. 

 

 I'm simply questioning late war German water methanol injection systems when forced to run without methanol additives would be as effective in suppressing knock with just water alone, as Methanol/ethanol have anti knock properties. I understand the concept of using water injection in piston engines.   

 

edit: I'm also surprised the Germans knighted their scientists. must have been a really crazy ceremony at Buckingham palace in 1948, you know bringing all the German leadership out of Nuremburg to do it.  

Edited September 30, 2021 by gimpy117

[CUJO_1970]

55 minutes ago, 357th_Dog said:

Interesting, I wasn't aware that Sir Harry Ricardo, who invented water-methanol injection to boost the performance of internal combustion engines, was German. 

 

Sir Harry Ricardo did not invent water injection. He did research it, as did a lot of people, and write about it in the 1930s. Both Daimler and Rudolph Diesel wrote about water injection (Diesel wanted to add water injection to his Diesel engine) as it was known in the late 1800's/early 1900s. You just looked up the first Google/Wikipedia search you could find and went with it.

 

Nobody knows who "invented" water injection as it's been around since the dawn of the internal combustion engine.

27 minutes ago, gimpy117 said:

edit: I'm also surprised the Germans knighted their scientists. must have been a really crazy ceremony at Buckingham palace in 1948, you know bringing all the German leadership out of Nuremburg to do it.  

 

You might want to do a little research on German Aero Engineers after WW2 as they were shipped en masse to the United States (Project paperclip) Great Britain and Russia but definitely not Nuremburg. Rocket science and sweep theory was not considered a war crime but a valuable commodity to a nation like the United States that had a lot of catching up to do and a lot of redesigning to do once enlightened.

 

Or just look up this guy:

 

 

 

 

 

On 9/26/2021 at 12:08 AM, gimpy117 said:

that's kind of dubious. so he says they're just porting water in the engines? no methanol?  

 

[ZachariasX]

1 hour ago, gimpy117 said:

I'm simply questioning late war German water methanol injection systems when forced to run without methanol additives would be as effective in suppressing knock with just water alone,

Knock is not a problem at all in that case. Late war German C3 actually was even a tad better of a performer than commonly used Allied fuel at high power settings. What matters is cylinder head temps. You don‘t want to burn your valves. Water is about the best practical heat sink you can put in your system for cooling. You need only water. Even the Herrenrasse at BMW don‘t use methanol for extra power anymore, as, same as the Allies then, they reliably get the energy needed for desired power output from the fuel alone. And yes, you can put in anti-freeze at your discretion. Driving around a busted tank of ice isn‘t most peoples cup of tea.

 

The DB engines were not knock limited, the they were CHT limited due to bad materials. They needed all the tricks they could come up with to get power parity with a competition that could use better materials. The Double Wasp also requried water injection, because it is a radial (that run higher CHT) and it is a simple 2 valve system that run hotter than 4 valve systems. The Double Wasp was one of the few Allied engines that shared issues DB encountered, and it got the same solution. But it only had (cheap) methanol for anti-freeze, not for compensating a deficiency of getting the power required from your aviation gasoline.

 

MW50 is actually a dumb thing to put in an engine that can draw the added power of charge cooling from the gasoline, because it is a less good heat sink and it enriches the mixture compared to water that leans it. Remember, at these poweres, we are in rich-rich settings, typically past the „most power“ peak of your mixture. But this again depends heavily on the actual fuel you are using.

 

Being good at research is one thing. You need to be good at production too.

[Cpt_Siddy]

10 hours ago, gimpy117 said:

"though commonly referred to as water, the solution actually used is a mixture of water and alcohol" 

it would seem that late war, the only ones running pure water were the Germans, out of a shortage of methanol. 

 

 I'm simply questioning late war German water methanol injection systems when forced to run without methanol additives would be as effective in suppressing knock with just water alone, as Methanol/ethanol have anti knock properties. I understand the concept of using water injection in piston engines.   

 

 

I am not sure if you are trolling now or ...

 

but consider that:

Latent heat of fusion for methanol 3.1773 kJ/mol

vs water at 6.01 kJ/mol

 

So water is 2x/mol better at absorbing heat from the charge air.

 

The purpose of spraying a fine mist of water in to hot charge air of ICE was to cool it. Water has excellent properties when it comes absorbing heat when it changes state from liquid to a gas. Methanol was added as an antifreeze and some additives were added to form a thin layer of oil or other passive coating on the surfaces where water might have reach in the form of liquid mist. If you could have made a system where all water was reliably evaporated before it could contact any surfaces, and the corresponding water lines and tank could be reliably kept above freezing, you could have done away with the additives and go with pure water alone. 

 

This is not some secret black art that got lost in the haze of time. This is largely obsolete, quick and dirty, method of increasing your air charge (oxygen/fuel) in to cylinders without running the risk of it going off mid compression stroke. There was also some CHT issues that can be solved by cooling the initial charge. Remember, 20 degree cooler charge air translate in to ~150 (depending on engines compression) degree cooler compressed mixture before the ignition. 

Edited September 30, 2021 by Cpt_Siddy

[-=PHX=-SuperEtendard]

13 hours ago, CUJO_1970 said:

 

Sir Harry Ricardo did not invent water injection. He did research it, as did a lot of people, and write about it in the 1930s. Both Daimler and Rudolph Diesel wrote about water injection (Diesel wanted to add water injection to his Diesel engine) as it was known in the late 1800's/early 1900s.

 

It was a topic researched since decades before yes, and by different engineers/scientists of different nations. That's why claiming the allies copied it from the Germans is just ridiculous, specially when the allied implementation saw service/ was mass produced first.
 

Edited September 30, 2021 by -=PHX=-SuperEtendard

[Bremspropeller]

Knock, knock!

 

Who's there?

 

Herr Water.

 

Herr Water who?

 

Herr Water Injection.

[CUJO_1970]

1 hour ago, -=PHX=-SuperEtendard said:

It was a topic researched since decades before yes, and by different engineers/scientists of different nations. That's why claiming the allies copied it from the Germans is just ridiculous, specially when the allied implementation saw service/ was mass produced first.
 

Yes, but I’m not the guy that claimed it was copied so…thanks?

 

Many of the engineers (from whatever nation) working on early combustion engines where lettered in thermodynamics and pretty much all of them came from steam engine backgrounds. They knew all about water since the mid 1800s. 
 

Diesel jumped off a boat (or was pushed) and would not live to see what a profound impact his discoveries would have in the field of engine development. 

[gimpy117]

On 9/30/2021 at 9:50 AM, Cpt_Siddy said:

 

I am not sure if you are trolling now or ...

 

but consider that:

Latent heat of fusion for methanol 3.1773 kJ/mol

vs water at 6.01 kJ/mol

 

So water is 2x/mol better at absorbing heat from the charge air.

 

The purpose of spraying a fine mist of water in to hot charge air of ICE was to cool it. Water has excellent properties when it comes absorbing heat when it changes state from liquid to a gas. Methanol was added as an antifreeze and some additives were added to form a thin layer of oil or other passive coating on the surfaces where water might have reach in the form of liquid mist. If you could have made a system where all water was reliably evaporated before it could contact any surfaces, and the corresponding water lines and tank could be reliably kept above freezing, you could have done away with the additives and go with pure water alone. 

 

This is not some secret black art that got lost in the haze of time. This is largely obsolete, quick and dirty, method of increasing your air charge (oxygen/fuel) in to cylinders without running the risk of it going off mid compression stroke. There was also some CHT issues that can be solved by cooling the initial charge. Remember, 20 degree cooler charge air translate in to ~150 (depending on engines compression) degree cooler compressed mixture before the ignition. 

no I'm not trolling, I'm pointing out that methanol is also a anti knock additive, unless this wasn't known at the time or really wasn't used for that purpose here. It's still used in high performance automotive applications even when freezing isn't an issue. so with water only you still get the vast majority of  cooling but less octaine boost. I've also read that water only can in effect reduce compression ratios of and engine. some on here are saying the DB engines are only CHT limited and not knock limited, so maybe it was just purely for antifreeze...although it's puzzling they weren't taking advantage of methanol.   

[Cpt_Siddy]

14 minutes ago, gimpy117 said:

no I'm not trolling, I'm pointing out that methanol is also a anti knock additive, unless this wasn't known at the time or really wasn't used for that purpose here. It's still used in high performance automotive applications even when freezing isn't an issue. so with water only you still get the vast majority of  cooling but less octaine boost. I've also read that water only can in effect reduce compression ratios of and engine. some on here are saying the DB engines are only CHT limited and not knock limited, so maybe it was just purely for antifreeze...although it's puzzling they weren't taking advantage of methanol.   

 

Methanol-only makes sense only in very high RPM engines as it changes phase faster than water and you don't want any remaining liquid water during the combustion, that will eat horsepowers. 

 

I am talking crazy RPM's here, nothing ww2 aero-engine was even remotely capable of reaching-

Edited October 1, 2021 by Cpt_Siddy

[ZachariasX]

7 hours ago, gimpy117 said:

no I'm not trolling, I'm pointing out that methanol is also a anti knock additive, unless this wasn't known at the time or really wasn't used for that purpose here. It's still used in high performance automotive applications even when freezing isn't an issue. so with water only you still get the vast majority of  cooling but less octaine boost. I've also read that water only can in effect reduce compression ratios of and engine. some on here are saying the DB engines are only CHT limited and not knock limited, so maybe it was just purely for antifreeze...although it's puzzling they weren't taking advantage of methanol.   

There is merit the anti-knock effect when MW50 is used with B4 fuel. Then it actually makes sense, especially since Bosch injectors were struggling at the high fuel flows in later engines. C3 injection (to add C3 to C3 fuel) did just help for that.

[6./ZG26_Klaus_Mann]

On 10/2/2021 at 12:43 AM, Cpt_Siddy said:

 

Methanol-only makes sense only in very high RPM engines as it changes phase faster than water and you don't want any remaining liquid water during the combustion, that will eat horsepowers. 

 

I am talking crazy RPM's here, nothing ww2 aero-engine was even remotely capable of reaching-

The BMW 801 at 2700RPM is running at 14m/s Average Piston Speed.

The DB605 at 2800RPM is running 15m/s Average Piston Speed.

The JuMo 213 at 3250 is running nearly 18m/s Average Piston Speed.

 

Most normal, modern Cars hit their Rev Limiter at 16m/s and Sport Performance Engines at 20.

 

These old Aero Engines are running really fast and are revving really high.

[Cpt_Siddy]

1 hour ago, 6./ZG26_Klaus_Mann said:

The BMW 801 at 2700RPM is running at 14m/s Average Piston Speed.

The DB605 at 2800RPM is running 15m/s Average Piston Speed.

The JuMo 213 at 3250 is running nearly 18m/s Average Piston Speed.

 

Most normal, modern Cars hit their Rev Limiter at 16m/s and Sport Performance Engines at 20.

 

These old Aero Engines are running really fast and are revving really high.

 

Yeah, all of those are rookie numbers compared to the more extreme engines we see in some racing and drag sports. 

The discussion was about methanol's ability to resist knock. As a pure fuel it might fare better than actual charge air cooling, as our discussion was about what actual application do methanol get used and why. And is there actually any point of mixing methanol in water injection system where there is no risk of it freezing and when you have ample time for the water to do its job and changing its phase from liquid to gas. 

 

As far of its thermal properties go, no, methanol offers no advantages over water. But it does change phase faster and can be used as part of an actual fuel because it has caloric value. This usually come in to relevance when you get stupendously fast RPM's you get from some of the more extreme engines out there. 

 

I am talking here  from the first principles of the chemical properties of methanol. There might be other issues like rules and regulations that might be involved in its actual use in industry. 

[6./ZG26_Klaus_Mann]

@Cpt_SiddyAre you sure? Methanol as used in the highly Supercharged Engines, such as the Big Blocks in Monster Trucks, comes into it's Power band at roughly the same Piston Speeds as in our discussed Engines.

And most of the high Revving other ones also get into their Powerband well before their Redline.

[Cpt_Siddy]

4 hours ago, 6./ZG26_Klaus_Mann said:

@Cpt_SiddyAre you sure? Methanol as used in the highly Supercharged Engines, such as the Big Blocks in Monster Trucks, comes into it's Power band at roughly the same Piston Speeds as in our discussed Engines.

And most of the high Revving other ones also get into their Powerband well before their Redline.

Yeah but are they used as a charge coolant or actual fuel. 

 

Methanol itself has more stable auto ignition characteristics than most other hydrocarbons found in fuels, 470 C (this is close to 150 oct fuels auto ignition but it's lead free ? )   vs , say Hexanes 230 C. (hydrocarbons are also a tricky business because they have many forms they can be found in, containing different number of Hydrogen in them depending of their conformation, effecting their properties, you can have aliphatic unsubstituted octane, or total  jumble of a mess that is also, technically, octane.)

 

This is no longer charge cooling but a totally sidestepping charge cooling and switching to more stable fuel. Judging by the properties alone, only reason you want to use methanol in your charge cooling over water is when you have very limited time available for evaporation (poor atomizer). Other than that, you get better anti knock effect from Methanol by just adding it directly to the fuel. You will lose some of the oomph but you will gain some knock protection. 

Edited October 3, 2021 by Cpt_Siddy

[MiloMorai]

This boat is powered by a 468ci blown Chevy using only methanol as the fuel.

[W_Braun]

On 9/30/2021 at 6:01 AM, CUJO_1970 said:

 

 

Or just look up this guy:

 

 

 

 

 

 

 

My Grandpa. 

[6./ZG26_Klaus_Mann]

Not Off-Topic but Off-Current thingy we are doing here: Just found this in my History. 

One is the 109Gs Water Radiator Inlet, the other of a Spit Mk.IX. 

Yes, the 109 has the same width intake, but only two bones of my Index Finger in Intake Height. The Spitfire my Hand can barely cover. 

 

[JtD]

The cooler inlet flap on the 109 appears to be closed, in opened state it would be roughly twice the size. Hard to tell from the picture.

 

Still, the Merlin being more powerful and not having a separate oil cooler, even with somewhat higher coolant temperatures and therefore better heat transfer, would probably require more air through the radiator.

[ZachariasX]

1 hour ago, 6./ZG26_Klaus_Mann said:

es, the 109 has the same width intake, but only two bones of my Index Finger in Intake Height. The Spitfire my Hand can barely cover. 

As @JtD pinted out, the 109 radiator inlet there is on closed position.

 

The Spitfire actually has considearbly less radiator drag than the 109 for the simple fact that at 130°C coolant temp, heat transfer is much better than at 100°C. The Bf-109 could't have such high coolant temperatures for several reasons. The Spitfire in consequence only has one such intake for the whole water cooler and up to Mk.V, it had a much smaller additional sized oil cooler. Frim the later Marks on, it had to symmetrical radiator bays, but these housed water cooler, intercooler and oil cooler. The Bf-109 had three and not two coolers: two dedicated for water cooling in the wing and a third for oil cooling underneath the engine (that the Spit never had).

 

The Germans were painfully aware their cooling system being sub par, but the way the water coolers that were made in Germany (flat pressed pipes) didn't tolerate much internal pressure. If they wanted to raise coolant temps, they had to completely redesign their coolers and that was not a practical thing to do.

 

 

The "MesserSpit" was actually a test how the British high pressure water cooling would do on the DB engines, and results were rather remarkable. The MesserSpit (and Mk.V withe the engine of a 109F) had almost the performance of the Merlin 61 powered Spitfire, outclassing bothe the Spit Mk.V and the original Bf-109F.

 

The Bf-109 had in all variants considerably more radiator drag than the Spitfire. The Mustang was the plane that considerably improved the radiator design of the Spitfire.

[JtD]

The Spitfire was powered by a DB605, and the radiator installation of this Spit V was 52% the cross section with 96% the cooling efficiency of a Bf109G (oil coolers excluded).

As you say, this was related to technologies available/used, but size does not translate 1:1 into drag - see Mustang.

 

The Messerspit outclimbed the 109G, in terms of speed it was considerably slower at low altitudes. It was about as fast at 10km and faster above. All this can be explained by lower wing loading and larger span of the larger Spitfire air frame - less induced drag but more parasitic drag. It doesn't really show a significant advantage for the Spitfire in terms of radiator drag (and that's just a V, the IX's worse).

[DBFlyguy]