Author Topic: Late Me 109 G & K engine settings  (Read 12610 times)

Offline mw

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Late Me 109 G & K engine settings
« on: March 30, 2005, 02:38:04 PM »
Hello:

I've been researching engine settings/limitations on late model Me 109s. Recently I've found some interesting documents bearing on the subject, see my findings at:

http://www.spitfireperformance.com/spit14v109.html

Regards,
Mike

Offline Angus

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Late Me 109 G & K engine settings
« Reply #1 on: March 31, 2005, 04:39:25 AM »
Greetings!
I have a blurry copy of a 109 Flight test, 109G5 to be precise, from Augsburg, dec 1943.
Exhaust pressure seems to peak out at 1.42, intake 1.3.
Which one is the common in use?
Anyway, I have the specs of performance, as well as something that really boggled me:
"Um den noch nicht eingelaufenen motor zu schonen, wurde erst ab etwa 6 km höhe mit kampfleistung (n = 2600 u/min, pb = 1.3 ata) gestiegen.

So, they didn't want to roast the not fully flown in engine?

Anyway, boggles me that they are still putting out reports of 1.3 ata tests in 1944.

I'll be back with the flight data if you like. Was just graphing this together with a Spitfire from 6 months before for fun, hehe.
Maybe you have this test already?

Best regards

Angus
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline Kurfürst

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Late Me 109 G & K engine settings
« Reply #2 on: March 31, 2005, 04:42:43 AM »
Again, a lot of things are wrong in this article. Many of these have been poitned out before, ie. the mixing of K-6 charts labeled as K-4 etc, maximum performance of the K-4 drawn with lines that are barely visible, flawed translation of original documents with a complete different meaning in than the original. The 1.8ata climb chart are also wrong and show performance WITHOUT MW-50... I don`t understand why these errors are left in the article, if they are known and pointed out already, and they were shown to you. The details are in my article if you missed them.

Another thing is representing the fact that the DB 605 DB`s max boost was 1.8ata... how is this supposed to prove the DB 6605 DC [/U] was not cleared for 1.98ata? Why was the DC table cut off from the document...? The DB was never supposed to run on more than 1.8ata with B-4 + MW, the DC could either run on 1.8 or 1.98ata with C-3 + MW. Mixing the two can be misleading.

I have compiled an article correcting in point,and it can be read here. It will be soon updated if further errors are found in the article on SP.

http://www.kurfurst.atw.hu/articles/MW_KvsXIV.htm

In view of the written orders by the OKL, the statement that there`s no evidence to 1.98ata being used by operational units can hardly be sustained. I am looking forward that you point out this fact in your article.

Acording to a classified order dated 20th March 1945 from the LW high command (OKL, Lw.-Führüngstab, Nr. 937/45 gKdos.(op) 20.03.45) :

"The development in the equipment status of day fighter units is based on the standard types laid down in the emergency program and anticipates :

 
for Bf 109 units    : K-4

for FW 190 units : D-9, D-12 with changeover to Ta 152 H and C

 
The arrival of the Ta 152 and it`s assignment to FW 190 units will result in an improvement in the equipment status of these units.

Essentially Bf 109 development will conclude with the K-4 an will inevitably lead to the conversion of Bf 109 units - those not scheduled for disbandment - to TL (jet fighters). Homogeneity of the equipment is to be strived for, combination of similar types is temporary and to be accepted based on levels of production."

 
The proposed changes to units equipped with Bf 109 were as follows :

 

OKL, Lw.-Führüngstab, Nr. 937/45 gKdos.(op) 20.03.45
 
No. Unit Present type Convert to Notes
1. III./ JG 1 Bf 109 G-10 He 162 (April/May) -
2.  II. / JG Bf 109 G-10 K-4 when deliveries permit -
3. III. / JG 3 Bf 109 K-4 no change -
4. III. / JG 4 Bf 109 K-4 no change -
5. IV. / JG 4 Bf 109 K-4 K-4 -
6. III. / JG 5 Bf 109 G-14 K-4 when deliveries permit -
7. IV. / JG 5 Bf 109 G-14 K-4 when deliveries permit -
8. III. / JG 6 Bf 109 G-14/AS K-4 when deliveries permit -
9. II. / JG 11 Bf 109 G-10 K-4 when deliveries permit -
10. I. / JG 27 Bf 109 K-4 no change boost increase to 1.98 ata
11. II. / JG 27 Bf 109 G-10 K-4 when deliveries permit -
12. III. / JG 27 Bf 109 G-10 no change boost increase to 1.98 ata
13. I. / JG 51 Bf 109 G-14 K-4 when deliveries permit -
14. III. / JG 51 Bf 109 G-14 K-4 when deliveries permit -
15. IV. / JG 51 Bf 109 G-14 K-4 when deliveries permit -
16. II. / JG 52 Bf 109 G-14/U4 K-4 when deliveries permit -
17. III. / JG 52 Bf 109 G-14 K-4 when deliveries permit -
18. II. / JG 53 Bf 109 K-4 no change -
19. III. / JG 53 Bf 109 K-4 no change boost increase to 1.98 ata
20. IV. / JG 53 Bf 109 K-4 no change boost increase to 1.98 ata

21. I. / JG 77 Bf 109 G-14/U4 K-4 when deliveries permit -
22. II. / JG 77 Bf 109 G-10 K-4 when deliveries permit -
23. III. / JG 77 Bf 109 G-10 K-4 when deliveries permit -
24. III. / JG 300 Bf 109 G-10/R6 via K-4 to Me 262 planned, deadline
25. IV. / JG 300 Bf 109 G-10/R6 via K-4 to Me 262 -
26. I. / KG(J) 6  Bf 109 G-10/R6 K-4/R6 when deliveries permit -
27. II. / KG(J) 6  Bf 109 K-4 K-4/R6 when deliveries permit -
30. I. / KG(J) 27 Bf 109 G-10/R6 K-4/R6 when deliveries permit -
31. I. / KG(J) 55 Bf 109 G-10/R6 - -
32. II. / KG(J) 55 Bf 109 K-4 - to industrial defense
33. Ist Italian FG Bf 109 G-10 K-4 when deliveries permit -
34. IInd Italian FG Bf 109 G-10 K-4 when deliveries permit -
35. IIIrd Italian FG Bf 109 G-10 K-4 when deliveries permit -

Source : Fritz X. Kober - Jakob Maria Mathmann : The Messerschmitt Bf 109 Vol.2. Schiffer Publishing, 1996.  
 
This order, apart from ordering 90% of the existing 109 units to convert to the Bf 109 K-4 as soon as deliveries permit, also notes in relation of I./JG 27, III./JG 27, III./JG 53, IV./JG 53 to increase the maximum boost pressures to 1,98 ata manifold pressure. It is not known if and how many units had converted to 1,98ata before that order came, but it should be noted these units, in particular III./JG 27, III./JG 53 and IV./JG 53 were the major users of the Bf 109 K-4 in the Lufwaffe.

I might add that in view of these errors, these articles that concentrate on positive things for the Spits, and only the - sometimes unsupported - negatives of the 109s effect very negatively the credibility of your site in the flight communities.
The Messerschmitt Bf 109 Performance Resource Site
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Offline straffo

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Late Me 109 G & K engine settings
« Reply #3 on: March 31, 2005, 05:05:26 AM »
What engine had the 109G4 ?
I've read somewhere DB601 but I find it strange and I don't want to risk my life doing  a speleologic expedition in my library :)

Offline Kurfürst

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Late Me 109 G & K engine settings
« Reply #4 on: March 31, 2005, 05:10:31 AM »
G-4 ? DB 605 A-1 with 1550 PS peak output at altitude. Only a few G-0 prototypes were fitted with DB 601E in 1941.

Like G-1, G-2, G-3, G-5, G-6. It could be boosted with GM-1, that increased speed by 120 (!!) km/h, 1500m above rated altitude.

Sadly mentioning the use of GM-1 by Bf 109 types is also absent from Mr. Williams article, though I miss objectiveness a lot more.
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Offline mw

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Late Me 109 G & K engine settings
« Reply #5 on: March 31, 2005, 07:45:04 AM »
Hi Angus:  I take it you are referring to "Leisitungen Me 109 G mit DB 605 AS".  Nice trials report.  I think you are also referring to Ladedruck and Gebläsedruck?  Ladedruck is equivalent to boost pressure or manifold pressure, in this case 1.3 ata for the 109 Gs.  Gripen can explain Gebläsedruck better than me ;) Maybe he can chime in or you can send him a note.   I was just reading yesterday a report that mentioned breaking in a DB 605 D for 15 hours before going to emergency power.  In this particular case the engine blew anyway ;)

Offline straffo

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Late Me 109 G & K engine settings
« Reply #6 on: March 31, 2005, 08:01:34 AM »
Thank Kurfürst ,I had something like that in my head but was unsure.

Offline Kurfürst

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Late Me 109 G & K engine settings
« Reply #7 on: March 31, 2005, 10:32:20 AM »
What gives, it seems we are really honoured in another thread where Mike spreads his seed. It happens that a real world flight mechanic, currently working on the restored Bf 109 G-10s engine made some comment on this article. I hope it would be interesting to post, and that he don`t mind :


"Hi Mike. Thanks for posting the info. An important thing to note is the shortage of information about the performance of the 109's at the Sonndernotleistung power setting. Some of your graphs are confused with many lines of lower-power setting performance for the 109's against max-performance for the Spit. It is also important to note that the availability of a full 10min @ Sonndernotleistung per use was a big advantage! Combat climbs and long periods of fighting at full power were possible with MW.
Finally, beware of misinterpreting details on the late DB power settings. Quite often (because of the multiple settings available) graphs and text will refer to motors set for 1.98 or 1.8 ata, when the actual performance being described is at a lower power setting.
SM "


If you visit LEMB, be sure to read schwarze mann`s post on piston engines, this man is a wealth of knowladge on them.


Angie,

Geblasedruck is the pressure in the supercharger itself, usually somewhat higher than specificed,which is then cut back to the proper pressure.


Mike,

your site is really excellent when it comes to Spitfires. Look what I just found about the Griffon engines reliability :

.....2.3 Engine details and relevant limitations. The tests were commenced with a Griffon engine, number 1650 fitted. This engine failed before the tests were completed and the number of the replacement Griffon 61, was 16680. The following details apply to both engines :-

http://www.spitfireperformance.com/la187.html
« Last Edit: March 31, 2005, 10:39:56 AM by Kurfürst »
The Messerschmitt Bf 109 Performance Resource Site
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Offline Angus

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Late Me 109 G & K engine settings
« Reply #8 on: March 31, 2005, 11:02:43 AM »
So, when referring to the boost, are you referring to the lower or the higher figure?

BTW, is there some reliable data about when what partucular ata pressure was cleared for common use?
For it still baffles me that 1.3 is put as a max on a test plane in january 1944.
Oh, you might be able to actually see it from the performance.
ok, here goes:
109G5 werkno 26108 SL RR, engine DB 605 AS-0
ladedruck 1,3, geblasedruck 1,42
SL speed 315 mph, radiators closed.
10000ft 363
16000ft same
27200ft 406....full throttle height
34500ft 391
36850ft 351
39700 feet 332 mph, - ceiling.
It caught my eye, that they did not want to run the motor at higher setting in order not to overstrain it (German:Schonen).

Anyway, does anyone here have TAS to IAS formula (or a calculator), and also how to convert ata to the allied scale????

THX in advance
;)
It was very interesting to carry out the flight trials at Rechlin with the Spitfire and the Hurricane. Both types are very simple to fly compared to our aircraft, and childishly easy to take-off and land. (Werner Mölders)

Offline gwshaw

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Late Me 109 G & K engine settings
« Reply #9 on: March 31, 2005, 11:35:58 AM »
Quote
Originally posted by Angus
Anyway, does anyone here have TAS to IAS formula (or a calculator), and also how to convert ata to the allied scale????

THX in advance
;)


I don't remember the formula for TAS to IAS conversions off the top of my head. But for MAP conversions here you go.

ATA to Inches Hg

ATA * 28.96 = Inches Hg

+PSI to Inches Hg

(PSI * 2.04) + 29.92 = Inches Hg

Inches Hg to +PSI

(Inches HG - 29.92) / 2.04 = +PSI

Greg Shaw

Offline MiloMorai

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Late Me 109 G & K engine settings
« Reply #10 on: March 31, 2005, 11:55:56 AM »
Quote
Originally posted by Kurfürst Angie ,

Geblasedruck is the pressure in the supercharger itself, usually somewhat higher than specificed,which is then cut back to the proper pressure.
 


LOL, you are real hoot, crying about people using BarbI. :rolleyes:

...........

What relevence does a Griffon 61 have since the Griffon 65 was the main engine used for the XIV.

It also should be noted that LA187 was the first Mk21, coming off the production line in  27-1-44. The test you linked to was between March and July 1945.


Now lets look at the units you claim were using 1.98, dispite the fuel shortage Germany had, and that Fw190A units could not operate without C3 fuel.

These numbers are for April 9 1945 only a couple of weeks after the date you give.

I./JG 27 had 29 'on hand' but only 13 flyable.
III./JG 27 it was 19 - 15
III./JG 53 it was 40 - 24
IV./JG 53 it was 54 - 27

total is 141 - 79

LOL, you moan about only 7 squadrons of Spit XIVs, even though there was more, which would be fully equiped.


Further you like to quote this:

The above given performances are certainly going to be reached with well-built serial production machines.

Yet, from a German document:

It makes no sense to increase the power output of the engine when on the other side the plane quality is decreasing dramatically

It is a dream that the a/c could reach the performance numbers for the test a/c.

Offline MiloMorai

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Late Me 109 G & K engine settings
« Reply #11 on: March 31, 2005, 03:14:31 PM »
Though for an early G-6, it would apply to later 109s.

Bf 109 written by Robert Michulec and published by AJ-Press (#43) - GM 1 on Bf 109G-6.:

p. 38-39:
Idea of changing GM1 installation appeared in August 1943 and introduced one large tank mounted vertically behind pilot's cockpit and fueled by one intake. Works started in Erla factory which co-operated with E-Stelle Rechlin since end of August. Calculations shown that tank installed behind third rib will move centre of mass about 30%. It was very troublesome and final report created in mid of October 1943 in E-Stelle Rechlin said that using this solution in combat is impossible because such equipped plane is useless in dogfight. Even when tank was filled with only 80 litres of liquid, centre of mass was moved about 26,1% and plane should be piloted by well trained pilot.

Offline Kurfürst

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Late Me 109 G & K engine settings
« Reply #12 on: March 31, 2005, 04:26:30 PM »
This is for the later G-6s, I am not even sure it speaks of the final version of the GM-1 installment, that become G-6/U2, and some equipment was removed to restore to Center of Gravity to cure the very problem that Milo pointed out about calculations on the prototypes. This plane used a simplified system for GM-1, an UNpressurized, heavy insulated tank mounted behind the pilot.

Earlier 109s used a different system, the GM-1 was mounted in light pressurized LUTZ bottles in the right wing (G-1 and G-3 had this standard, but G-2 and G-4 could be also retrofitted). It was also utilized by the 109 F-4/Z. With GM-1, max. speed was boosted by 120 km/h, making the maximum speed of the Bf 109G well over 700 km/h at altitude, making it the world`s fastest high altitude fighter when it appeared in 1942 - and it remained as such for a good while.
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Offline Kurfürst

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Late Me 109 G & K engine settings
« Reply #13 on: March 31, 2005, 04:41:12 PM »
Quote
Originally posted by Angus
So, when referring to the boost, are you referring to the lower or the higher figure?
[/B]



BTW, is there some reliable data about when what partucular ata pressure was cleared for common use?

For it still baffles me that 1.3 is put as a max on a test plane in january 1944.

It depends on, there could be many reasons, some brit test also tested below-max powers, too.


Oh, you might be able to actually see it from the performance.
ok, here goes:
109G5 werkno 26108 SL RR, engine DB 605 AS-0
ladedruck 1,3, geblasedruck 1,42
SL speed 315 mph, radiators closed.


Engine RPM would be more helpful (2600 would mean 1.3ata Kampfleistung, 2800 would mean 1.42ata Notleistung boost), but the above shows that on the tested plane the manifold pressure was 1.3ata, while before regulated into the engine, the supercharger itself worked it up to 1.42ata. It`s fairly logical, and the same on almost all engines. Even on the DB w. hydraulic clutch s/c, slightly higher pressure was developed, than it was simply regulated down to the proper pressure. Simple, it`s easy to get less pressure from a given supercharger performance to get constant, proper boost even in view of slight variations during operation, but you cannot get the proper pressure if it`s just as much or even less... consider it a 'extra allowance' factor, it probably also made the given engine less sensitive to the results of wear, missettings, production tolerances etc.

The given SL speed of 315 mph is what the official german datasheets give for G-6/AS at 1.3ata btw.




It caught my eye, that they did not want to run the motor at higher setting in order not to overstrain it (German:Schonen).

That`s standard practice with new motors, a 'break-in' is done before full power is used. Same as on new cars.


Anyway, does anyone here have TAS to IAS formula (or a calculator), and also how to convert ata to the allied scale????


Well 1 ata is 1 kg/cm2, which you can convert to imperial units. The British boost is relative above(+) or under the normal air pressure (1ata)
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Offline MiloMorai

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Late Me 109 G & K engine settings
« Reply #14 on: April 01, 2005, 02:24:43 AM »
Quote
Originally posted by Kurfürst
What gives, it seems we are really honoured in another thread where Mike spreads his seed. It happens that a real world flight mechanic, currently working on the restored Bf 109 G-10s engine made some comment on this article. I hope it would be interesting to post, and that he don`t mind :


"Hi Mike. Thanks for posting the info. An important thing to note is the shortage of information about the performance of the 109's at the Sonndernotleistung power setting. Some of your graphs are confused with many lines of lower-power setting performance for the 109's against max-performance for the Spit. It is also important to note that the availability of a full 10min @ Sonndernotleistung per use was a big advantage! Combat climbs and long periods of fighting at full power were possible with MW.
Finally, beware of misinterpreting details on the late DB power settings. Quite often (because of the multiple settings available) graphs and text will refer to motors set for 1.98 or 1.8 ata, when the actual performance being described is at a lower power setting.
SM "


If you visit LEMB, be sure to read schwarze mann`s post on piston engines, this man is a wealth of knowladge on them.
 


schwarze-man also said this:

On the thorny subject of the B/C motor availability I can only comment as a "nuts and bolts" DB specialist-not as a "historian": The official Daimler-Benz manual for the DB u. DC was already in its third issue by 1 dez '44. My feeling is that DB produced both the types from around late autumn. This would see them in airframes that winter. The arguments from Rechlin about being bypassed on testing at 1.98ata would seem to indicate that 1.98 (DC/ASC) motors had been issued already and they were peeved not to be in the loop! I suspect that the 1.8ata (B4) motors were the great majority. Finally, it is not suprising that these engines suffered short-lives, they were hurriedly built and doubtless handled with less than the high standard of care such high performance motors require for a reasonable life-span.
SM