Late Me 109 G & K engine settings

[pasoleati]

Kurfürst, please tell me how Merlin´s pressurized cooling went to "extremes"? Comparing operating data (i.e. coolant temps and flows), this claim cannot simply be backed up.

And please tell me which other V-12 aircraft engines have had different CRs on the two banks? I am afraid none. Actually, to be precise, which other engines with fork-and-blade conrods did that? Radials have slightly different CR in the cyls due to the conrod arrangement, as do V engines with articulated rods.

If the DB did that to "smooth the running", boy they screwed up the basic design if such Heath Robinson methods were required!.

IMHO the strongest theory on this is the oil seepage theory suggested by former German wartime engine designer Dr. Max Bentele.

[pasoleati]

Kurfürst, have you taken into account that sfc is calculated in g/hp/hr? German C3 weighed some 10-15% more per litre than the Allied 100/150 did (C3 data from fischer-tropsc archive).

Speaking of high boost, you don´t obviously understand anything about this.
An example:
Engine A: a naturally aspirated engine has its CR raised from 5 to 8. BMEP (and thus power) rose 10%, sfc improved by 18%, but the peak pressure (which defines mechanical stresses and detonation limit) rose by 63%.

Engine B. CR=5, but a supercharger is added providing 50% increase in MAP (i.e. 1.5 ata). SFC and the eak pressure remained the same (thus both operated on the same PN fuel) but the BMEP (and thus power) rose by no less than 54%! Can there be more convincing evidence to prove the stupidity of DB???

[MiloMorai]

Non-responsive

[Kurfürst]

Originally posted by pasoleati
Kurfürst, please tell me how Merlin´s pressurized cooling went to "extremes"? Comparing operating data (i.e. coolant temps and flows), this claim cannot simply be backed up.

I am sorry, but it`s exactly the operating data that underlines this... ie. coolant temps. Ie. Jane`s on the Merlin 61 : "This pressurizing of the system raising the boling point of the coolant and permits the use of smaller radiators. The maximum permissable coolant temp by this means is raised to 135 Celsius."

In comparison DB only used slight pressurization, as evident that the boiling temp was only 115 in that system. Only a sidenote that while the RR design method would allow neat radiators, Supermarine was 'successfull' completely scr*wing that advantage up, and mounting by far the WORST radiators ever on a ww2 airplane.

And please tell me which other V-12 aircraft engines have had different CRs on the two banks? I am afraid none.[/B]

 

Paseolati, I am afraid I cannot comment in this that it`s barely convincing if you don`t know why DB used this design feature, which was followed in all DB 601s, 605s, 603s etc. Tell me why they kept in the whole line if it was so bad, it`s just hard to believe that the leading engineers of one of the world`s largest aero engine company were simply out of their mind as you suggest. The reason for different CR is not yet fully explained, however couple of good threads were on it in the LEMB and the Lair. Such feature could be to counter propeller torque as well.

Kurfürst, have you taken into account that sfc is calculated in g/hp/hr? German C3 weighed some 10-15% more per litre than the Allied 100/150 did (C3 data from fischer-tropsc archive).[/B]

Still that would unaccount for the rest 20-30-40% higher specific consumption of the Merlins. Plus, the same trend is show with the lighter B-4, which is 10% lighter per little than C-3, thus weighting just as much as allied fuels.. yet, still less consumption. Ie. B-4 running DB 605A developed a max of 1550 PS, consuming 460 lit/h, contemporary Merlin 61 developed 1565 HP and cosumed 130 igph or 590 lit/hour... 28% more than the DB 605.

What was the spefic weight of Allied 100 and 150 grade fuel anyway?

Just dig up some numbers yourself and that`s the same you will find in every single Merlin consumed on avarage 30% more than a DB on the same power.

Imho R-R tried to simple development way to get easily large powers out of the engine fast (keeping the same small engine and just increasing MAP) but they felt the increasing disadvantages in the long term and gradually put themselves into disadvantage. DB`s design way was the harder way, but they moved early on to bigger displacement, direct injection, and this yield them increasing dividients as MAP and CR was gradually increased, with no such disadvantages.

[Angus]

Ahemm, Barbi.
First this:
"the world`s largest aero engine company " = DB

Rubbish. the 109 = the world's most produced fighter aircraft.
But looking deeper into it, you'll find out that the biggest manufacturers of aero engines would be the US, the Brits, and the USSR.
Wright cyclone, P&W, RR etc.
Remember that the RR powered the Spits (20.000), the Hurricane (13000), the mossie (x*2), the Lancaster (x*4), the Firefly, the Fulmar, the P51,,,,want more???
That's from RR vastly more than the DB

Secondly, - of fuel consumption.
Here are some facts:
Early Spitfires had equal or same fuel loads as the 109's. Operational range as well as time in the air seems to be roughly equal, or better.
The DB is an engine with a much leaner mixture since it has a lot more volume, - if it is using the same amount pr time at the same rps, that difference would be near 30% or so. Or not? Can't work both ways.

[MiloMorai]

Pratt & Whitney production from 1941 to 1945:

R-985 - 36,036
R-1340 - 24,915
R-1830 - 166,504
R-2000 - 10,782
R-2800 - 114,073
R-4360 - 152

TOTAL - 352,462

[Angus]

WOW!

[MiloMorai]

Angus, a couple of quotes by LW aces:

Johannes Steinhoff, Sicily, Commander JG 77 (July 1943):

    The Malta Spitfires are back again... They're fitted with a high altitude supercharger and at anything over twenty-five thousand feet they just play cat and mouse with us.

    At 28,000 feet the Spitfire could turn in an astonishingly narrow radius. We on the other hand, in the thin air of those altitudes had to carry out every maneuver with caution and at full power so as not to lose control.

        Johannes Steinhoff, Messerschmitts Over Sicily, (Stackpole Books, 2004), pp. 97-98, 111.

Günther Rall commented on the Spitfire, having had the opportunity to fly various captured allied aircraft, as well as the Me 109G:

    The Spitfire, too (referring to the P-38 with power ailerons), was a very maneuverable aircraft, very good in the cockpit."

    ...Nicknamed Gustav, the BF 109G was well armed but not as light as the earlier E and F versions. Its more powerful engine meant higher power settings whose inital climb rate sent it soaring to 18,700 ft. in six minutes but at low speed the plane was difficult to handle. ...Most of us considered the 109G over-developed. Poor landing characteristics added to its woes.

[Kurfürst]

Originally posted by Angus
Ahemm, Barbi.
First this:
"the world`s largest aero engine company " = DB

[/B]

etc. Got difficulty reading Angie or you are misrepresenting my words on purpose? I wrote :

"...it`s just hard to believe that the leading engineers of one of the world`s largest aero engine company were simply... "

Guess you owe me an apology.

That's from RR vastly more than the DB

Hmm, the British needed American import Packard engines because they couldn`t produce enough for themselves... otherwise, the Merlin was the main w.allied engine... the DB just powered the Mtt fighters/zerstorers (mainly). The Jumo and BMW were just as important engines.


Here are some facts:
Early Spitfires had equal or same fuel loads as the 109's. Operational range as well as time in the air seems to be roughly equal, or better.

Never seen any proof to your 'fact' that early Spits would have any better range/endurance than the Emil. That the DB was more economic was balanced by the lower drag of the Spit I compared to the Emil, so range could besimliar and indeed it was.

Then Spits become more and more draggier, while 109s cleaned up considerably, and the Merlin`s consumption skyrocketed. None of the later Spits them could claim equal range/endurance as later 109. The last, the XIV was so bad that even with 50% more fuel carried, it had only 1/2 - 2/3 the range and endurance than the 109G/K. That`s from a BRITISH source...


The DB is an engine with a much leaner mixture since it has a lot more volume, - if it is using the same amount pr time at the same rps, that difference would be near 30% or so. Or not? Can't work both ways.

The DB worked at 2800, the Merlin at 3000 rpm, so possibly this is also a reason why the DB was more effient. The Griffon, despite being more powerful than the Merlin, consumed less... RR realized too late there`s no replacement for displacement.

[Kurfürst]

Originally posted by MiloMorai

Günther Rall commented on the Spitfire, having had the opportunity to fly various captured allied aircraft, as well as the Me 109G.[/i]

I doubt it`s his comment, more like the author`s who compiled that book on him. Of course it`s not at all a surprise that something is manipulated on the SpitPartisan site. The surprise when it`s is not...

[Angus]

BarbI, Rall rewrote his book. I have the German version also, it's stating the same thing with more detail.
He has no problems repeating that, in his own words I heard him state that there was usually no way a 109 could catch a Spitfire in a climb, and no way in a climbing turn.
I belive that I have actually typed some quotes from there before.
The last goodie, I read this morning. He was describing his encounters with USSR fighters over Romania. Something like "They posed no threat compared to a staffel of Spitfires"
Anyway, ONE of the biggest aero companies slipped my eye. Sorry for that, but a good thing I pointed out none the less.
As for the Spitfire MKI and 109E ranges, or generally other comparisons, let's begin with ranges.
109's had trouble going as far as London for combat, which is vastly shorter than the Spitfires ventured on rhubarb missions shortly later, and also shorter than Spitfire missions from many stations going inland to France in the Dunkirk evacualtion. (the Tommies on the ground saw not much precence of the RAF, however most of the interceptions took place much further inland).
I also ran across some crash reports and LW claims of Spitfires downed well inside Belgium for instance, - no drop tanks. If your range claim for the 109 would hold water, 109's could have been operating as far N-England with ease. So take that.
As for the performance of the two, they are good to compare, for the engine power is almost identical, as well as weights (Spit is heavier) and performance is very similar indeed.
The climb goes to the Spit while the speed goes to the 109 basically, and that's how it was throughout very much of WW2.
BTW, the climb figure from the Rall quote fits the test report I have from 1943/1944. At that time, Spit VIII's with top speed 400 mph+ and big internal fuel tanks to double the range, weighting 7200 lbs are some 5 minutes to the same altitude, peaking at mere 18 lbs boost.
Same timeframe.......both planes in service at the time with the above mentioned boosts.....

[MiloMorai]

Angus some numbers from the 109E-1, E-3 handbook:

SL
max continuous(2200rpm) - 267mi, 1.05hr
max economy(1300rpm) - 404mi 2.20hr

6km
max continuous(2400rpm) - 323mi 1.10hr
max economy(1600rpm) - 395mi 1.40hr

A Spitfire Ia had a range of 575mi and a combat range of 395mi.

Not that Barbarossa Isegrim will believe this since it goes against his uber 109 mentality.

ps

Angus.

Came across this little tidbit. RR was testing a Merlin in 1944 @ 36lb boost with ADI and 150PN fuel and getting 2640hp. Not bad for a puny little crappy motor, eh?

[Kurfürst]

Originally posted by Angus
BarbI, Rall rewrote his book. I have the German version also, it's stating the same thing with more detail. He has no problems repeating that, in his own words I heard him state that there was usually no way a 109 could catch a Spitfire in a climb, and no way in a climbing turn.

[/B]

How many engagement Rall had with Spitfire? A whole.... three? How many Spitfires he seen trying a corkscrew against him? Three? None?

That`s not much experience with that type compared a great many LW pilots. I have seen countless 109 pilots stating nothing could catch them in spiral climbs.Franz Stiegler says the opposite about the 109K, and the raw performance numbers prove Stiegler right, not Rall...

The last goodie, I read this morning. He was describing his encounters with USSR fighters over Romania. Something like "They posed no threat compared to a staffel of Spitfires" .

[/B]

Obviously, Soviet pilots had much less training than RAF or LW pilots, only Guards units were really good. Quite a few Soviet planes were much better than MkIXs, ie. Yak3 and LA5 and LA7. The Soviets received over a 1000 Mk IX Spits, but turned them down in favour of their domestic planes.

109's had trouble going as far as London for combat, which is vastly shorter than the Spitfires ventured on rhubarb missions shortly later, and also shorter than Spitfire missions from many stations going inland to France in the Dunkirk evacualtion..

[/B]

That`s interesting Angus, I presume since the 109E had trouble reaching London as you state, all those RAF pilots must have been liars reporting so many 109s around...? It`s probable that Angus is wrong then.

I wonder why you argue with British documents, Angus. All these docs say the Spit IX managed 450 miles on 85 impg. internal, while the 109G managed 750 miles on 88 impg. Do you claim this document is wrong?

BTW, do you have any documentation behind your statements? I guess not.

Funnily enogh, all documentation seems to suggest that the 109 was quite longer ranged, engine consumption specs also underline this... are we to believe that the plane with higher consumption, higher drag, and slight less fuel had even similiar range? A sensible person certainly would not.

If your range claim for the 109 would hold water, 109's could have been operating as far N-England with ease. So take that.

[/B]

Oh my oh my, what should I believe, Angus`s questionable facts and view on the 109`s combat history, or the official German and English reports and Handbooks issued by the manufacturer and intelligence teams?

BTW, the climb figure from the Rall quote fits the test report I have from 1943/1944.

[/B]

Well there`s a flight test report out there for the 109G that climbs at a peak of 4900 fpm at 1.3ata.
Which Spitfire could climb at 4900 fpm in 1942?

At that time, Spit VIII's with top speed 400 mph+ and big internal fuel tanks to double the range, weighting 7200 lbs are some 5 minutes to the same altitude, peaking at mere 18 lbs boost.
Same timeframe.......both planes in service at the time with the above mentioned boosts..... [/B]

Angus, are you aware that you are comparing the 109 at 30 min military rating to a Spitfire on 5min?
But indeed the Spit VIII had as much range as 109Gs, ie. ca. 740 miles on internal, but it required 120 gallons of fuel, while the 109G had only 88 gallons...

Climb/speed figures are the following for the 109G at 1.3ata 30-min rating.. This is not full power of course.
http://www.pbase.com/isegrim/image/5288901

[MiloMorai]

Angus,

Bf109 G-2 Bedienungsvorschrift-F1 Ausgabe Juli 1942

    *Note! "start and emergency power" is blocked and may not be used. *Achtung! Die "Start und notleistung" darf nicht benutzt werden, sie ist deshalb blockiert.

DB 605 Moteren-Karte 9 October 1942

    Take-off and emergency power is closed up to revocation , thus 2650 U/min (2600 U/min +2%) may not be exceeded in any flight attitude.

Die Start und Notleistung ist bis auf Widerruf gesperrt, es dürfen somit 2650 U/min (2600 U/min +2%) in keiner Fluglage überschritten werden.

From 109 G1, G2 and G6 Meßrief - 1942 and 1943

    Take off and emergency power: Provisionally closed after VT instruction Nr.2206.

Start und Notleistung: Vorläufig gesperrt nach VT-Anweisung Nr.2206

Bf109 G-2, G-4, G-6 Bedienungsvorschrift-F1 Ausgabe Juni 1943

    "Take-off and emergency power" may not be used; this stage is blocked in order to prevent over pressure.

Die Leistungsstufe 'Start -und Notleistung' darf nicht benutzt werden; um Überdrücken zu verhindern, ist diese Stufe blockiert.

Bf109 G-4/R3, G-6/R3 Bedienungsvorschrift-F1 Ausgabe Februar 1944

    Take-off and emergency power: may not be used, is blocked.

Start- und Notleistung: Darf nicht benutzt werden, ist blockiert.




The climb rate in the above graph is less than that on a graph I have > 21m/s(4134f/m) vs 18.5m/s(3642f/m). Both are for the G-1.

[Angus]

A quick reply.
"--------------------------------------------------------------------------------
If your range claim for the 109 would hold water, 109's could have been operating as far N-England with ease. So take that.
--------------------------------------------------------------------------------



Oh my oh my, what should I believe, Angus`s questionable facts and view on the 109`s combat history, or the official German and English reports and Handbooks issued by the manufacturer and intelligence teams? "

Please make yourself clear. The 109's range ended---where it ended. Coventry was too far for 109 activity while Middle Belgium was not to far for Spitfire activity. Intelligence teams or not, the aircraft went where they went.

As for your 109G climbing test from 1942, I'd really like to see the documented source. It conflicts completely with what I have. A lightened up aircraft perhaps????

Then to the Soviets. Pity they never got around handling the Spittys, for the LW lost more to the RAF in 1940 than to the Russian airforce in 1944.......
BTW, Rall engaged Spitfires and shot them down over Russia, as well as FLYING one as well. (As well as P51, P38, P47)
FYI, Johnny Johnsson jostled with a staffel of 109's from low alt to 19K where he left the party. That was in 1943 or 44........
Now, he and Rall did have some time to compare this, they became firm friends post war.