Engines power curves "Database"

[Alecvey8]

Hello
I'm new to this forum (besides I've done a lot of reading from here without creating an account).
For my personnal interest I've started to build an Excel file, trying to compile WW2 engines power curves database.
This is far from being finished but I would like to share it, and of course try to get more sources ...
I've gone through a lot of internet research, and the thred here "terminology and engine data".

I'm interested in "power curves" since there is a lot more to see than the usual "table data".

You may find attached the file. Don't flame me yet
Numbers in dark green are taken from original tables (and, to my opinion, are reliable values)
Numbers in light green are taken from power curves graph that seems to be also reliable to me (for example the one you could find on Kurfurst website for DB601/605 engines)
Numbers in yellow are deductions I made from power graphs.
Comments are added on engine title to better understanding

PLEASE DO NOT consider the other numbers, as it is "work in progress"

So far I try to cover the usual German engines.
I put engine type (e.g. "DB605 A") in light green when I consider data are complete. In all other cases I consider there is still work to do.

I appreciate help and feedbacks to improve the content.

Last update : 02/04/2021 "Engine v3" file.

Content update from V1 to V2 :
- DB 601 Ax / N / E completed : I add more values to better fit the charted curves
- DB 605 Ax and Dx completed : I add more values to better fit the charted curves
- Jumo 213A completed
- Comments added for some engines

Content update from V2 to V3 :
- added BMW 801 data (not yet finished...)

 

[Alecvey8]

So, I take this post here, I'll update from your inputs

Basically I started with German DB engines, for the moment mostly DB601 and DB605. Data are mainly from Kurfurst website.

I use PS and KM to fill the Excel ("german unit").
I use PS and Feet to plot graphs (I'm French Airline pilot so PS/Ft fits better for me, plus it would be better for comparison with British / Us engines later, provided I don't screw up with PS and HP ...)

My current questions :
- I can't get a lot of data about DB605AS, ASM, ASC(M) nor "D" series engines. Apart from max rated pwr @ TO and power @ S/C Alt.
- I'm confused with the following graph : the line starting from 1700 PS (1.7 ATA) is obtained with wich conditions ? C3 fuel and W/O MW50 ? If yes does that mean the "extra" 100 hp comes from MW50 charge cooling ?
Kurfürst - DB 601, 603, 605 datasheets - DB 605 AM
- I'm also confused with the following : looks like the numbers doesn't match which "reliable data "(for example the Jumo 213A curve), neither with the charted data on the same page (for example 1500 ps @ 6400 m for the table).
Kurfürst - DB 601, 603, 605 datasheets - DB 605 ASM

Any input, to light my brain, is appreciated

 

[Deleted member 68059]

So, I take this post here, I'll update from your inputs

Basically I started with German DB engines, for the moment mostly DB601 and DB605. Data are mainly from Kurfurst website.

I use PS and KM to fill the Excel ("german unit").
I use PS and Feet to plot graphs (I'm French Airline pilot so PS/Ft fits better for me, plus it would be better for comparison with British / Us engines later, provided I don't screw up with PS and HP ...)

My current questions :
- I can't get a lot of data about DB605AS, ASM, ASC(M) nor "D" series engines. Apart from max rated pwr @ TO and power @ S/C Alt.
- I'm confused with the following graph : the line starting from 1700 PS (1.7 ATA) is obtained with wich conditions ? C3 fuel and W/O MW50 ? If yes does that mean the "extra" 100 hp comes from MW50 charge cooling ?
Kurfürst - DB 601, 603, 605 datasheets - DB 605 AM
- I'm also confused with the following : looks like the numbers doesn't match which "reliable data "(for example the Jumo 213A curve), neither with the charted data on the same page (for example 1500 ps @ 6400 m for the table).
Kurfürst - DB 601, 603, 605 datasheets - DB 605 ASM

Any input, to light my brain, is appreciated

You can try to practise some German technical words, as your question on the 605 graph is clearly answered on the page (bold highlight is mine)

"
Das Triebwerk Daimler Benz DB 605 AM entsprach in seinem konstruktiven
Aufbau dem Flugmotor Daimler Benz DB 605 A, wurde jedoch mit dem Sonder-
kraftstoff C 3 betrieben. Bei Start- und Notleistung wurde die MW 50-
Zusatzeinspritzung verwendet. Die Laderzuschaltung begann bereits in
0,9 km Flughöhe. "

The line you refer to says "mit MW50"

Just start trying google translate and eventually you`ll remember the few pertinent words necessary to interpret these graphs.

 

[tomo pauk]

This thread might be of interest: link.

 

[Alecvey8]

Hi, thanks for both replies.
Snowy, I've been looking to translate german stuff (my wife is german, it helps up to the point it becomes very technical). I wanted to be sure of my "interpretation".
Thx Tomo for the link, as I've stated I really get a lot of information from this thread, unfortunately, it didn't "solve" my 1st and 3rd questions, maybe there's nothing available ...
But I'm still confused with the last graph, I get your "inverted colors" version with the colored lines, but it seems to still don't match with other sources of information.

 

[Deleted member 68059]

Hi, thanks for both replies.
Snowy, I've been looking to translate german stuff (my wife is german, it helps up to the point it becomes very technical). I wanted to be sure of my "interpretation".
Thx Tomo for the link, as I've stated I really get a lot of information from this thread, unfortunately, it didn't "solve" my 1st and 3rd questions, maybe there's nothing available ...
But I'm still confused with the last graph, I get your "inverted colors" version why the colored lines, but it seems to still don't match with other sources of information.

What other sources of information are you trying to "match" those graphs to ?

A tip, you`ll drive yourself nuts trying to make everything line up exactly, the situation was constantly changing, and also, not many people appreciate
that every test cell is different, unless you get every engine in the world and run them all on the same test cell, on the same day,
you`ll get very large differences (5% would not be at all unusual), on top of that, its sometimes unknown if power curves are
calculated, "expected", or from actual tests and from who`s test cell.

If would help if you try to explain what it is you are trying to do in terms of the end result ?

 

[tomo pauk]

Thx Tomo for the link, as I've stated I really get a lot of information from this thread, unfortunately, it didn't "solve" my 1st and 3rd questions, maybe there's nothing available ...
But I'm still confused with the last graph, I get your "inverted colors" version why the colored lines, but it seems to still don't match with other sources of information.

Apart from what Calum said above, sometimes the engine data was issued as 'provisional', sometimes it was discovered that those 'provisional' values were not as good once the tests in altitude chambers were done. Sometimes the same engine was not making the 'right' power, despite the RPM and boost equaling the 'book' values. A 3-5% difference in power was tolerated from manufacturers, that will mean a difference of easy 100 HP on the 2000 HP engines.
If the date of a data sheet or a graph is known (many times it is not), I myself tend to rate the late docs better than what I'd rate the early docs.

 

[Alecvey8]

What other sources of information are you trying to "match" those graphs to ?

For example , charted data and graphic data from here : (the 1500 PS @ 6.4 km).
Kurfürst - DB 601, 603, 605 datasheets - DB 605 ASM

I understand the precautions to take with the numbers, I'm conscious this can't be a "perfect match" everytime. My idea is to try to get similar and reliable values from different sources if possible. In my example, I'm trying to "plot" the ASM curve using charted data + data I get from the graph.

In terms of results I'm only trying to make a sort of database with engines power curves, (and saving the sources for personal interest).
I may also use Excel as a "comparison tool" from one engine to another. Maybe this will be interesting for someone else so I'll share this.

Thanks for your inputs guys.

 

[tomo pauk]

At any rate, I'm interested at your 'final product'

 

[pbehn]

Hi, thanks for both replies.
Snowy, I've been looking to translate german stuff (my wife is german, it helps up to the point it becomes very technical). I wanted to be sure of my "interpretation".
Thx Tomo for the link, as I've stated I really get a lot of information from this thread, unfortunately, it didn't "solve" my 1st and 3rd questions, maybe there's nothing available ...
But I'm still confused with the last graph, I get your "inverted colors" version with the colored lines, but it seems to still don't match with other sources of information.

Having worked in Germany Italy and France some technical stuff doesn't translate, English is perhaps the worst for it. Try using a German on line technical dictionary, then google translate

 

[Deleted member 68059]

For example , charted data and graphic data from here : (the 1500 PS @ 6.4 km).
Kurfürst - DB 601, 603, 605 datasheets - DB 605 ASM

I understand the precautions to take with the numbers, I'm conscious this can't be a "perfect match" everytime. My idea is to try to get similar and reliable values from different sources if possible. In my example, I'm trying to "plot" the ASM curve using charted data + data I get from the graph.

In terms of results I'm only trying to make a sort of database with engines power curves, (and saving the sources for personal interest).
I may also use Excel as a "comparison tool" from one engine to another. Maybe this will be interesting for someone else so I'll share this.

Thanks for your inputs guys.

For the the 605 with MW50 and 1.7ata, I would trust this more than stuff from online. This is an actual test data-set from Rechlin in 1944. Needs
you to put the pages together of course. These damn things are often like this, as this is printed from Allied microfilm, and their
cameras were set for Letter-size and often these charts are A3, so everything is chopped up like confetti.

I would regard this data as genuine, and accurate, I copied it myself in the archive so its not been fiddled with.

 

[Alecvey8]

Super !!! Thx a lot, awesome Stuff.
I'll update the file on the first post from time to time.

 

[Alecvey8]

I'll post up new versions of the file in the first post and update it accordingly
thx again snowy for sharing this about DB605 AS(M) curves. It looks very interesting, makes me thinking a little bit to usual 2 speeds S/C curves with the « smoothing » of the DB engines hydraulic drive
I have also one point to confirm about the two « upper curves », which both implies the use of MW50.
I tried to decipher what implies the terms « optimaler / normaler zuschaltung » to understand what makes the difference.
with help of my German wife, I would translate (in English, I'm French so ...) by « optimal / normal injection system ».
I'm quite sure I read somewhere (but can't find it, maybe it's incorrect) the there were two « MW50 » injection system, the first « retrofit » one which sprayed in the S/C inlet, and a second one (maybe « line fit ») which was more like intake port injection system.
well, this point may be wrong so I'm glad to be educated on this, but if it's right this can be the difference between « optimal » and « normal » curves ?

cheers

 

[Deleted member 68059]

I'll post up new versions of the file in the first post and update it accordingly
thx again snowy for sharing this about DB605 AS(M) curves. It looks very interesting, makes me thinking a little bit to usual 2 speeds S/C curves with the « smoothing » of the DB engines hydraulic drive
I have also one point to confirm about the two « upper curves », which both implies the use of MW50.
I tried to decipher what implies the terms « optimaler / normaler zuschaltung » to understand what makes the difference.
with help of my German wife, I would translate (in English, I'm French so ...) by « optimal / normal injection system ».
I'm quite sure I read somewhere (but can't find it, maybe it's incorrect) the there were two « MW50 » injection system, the first « retrofit » one which sprayed in the S/C inlet, and a second one (maybe « line fit ») which was more like intake port injection system.
well, this point may be wrong so I'm glad to be educated on this, but if it's right this can be the difference between « optimal » and « normal » curves ?

cheers

You`ve stumbled over another reason why there are so many problems matching up Daimler-Benz engine power curves. The somewhat wavy line marked "Zuschaltung", is
determined by the operation of the hydraulic coupling. This involves varying the oil content of the coupling internal cavity, which is itself governed by an external oil pump which ITSELF is governed by a small flexible bellows which senses air pressure. The system has a lot of small variable widgets to calibrate and set up, and is also very dependant on the properties and temperature of the oil itself. Thanks to this, the actual shape of that curve marked "Zuschaltung" varies by a surprising amount from engine to engine, so the "optimaler" note is basically saying "when the engine is carefully set up and working at its best, we could get THIS shape in theory", the "normaler" curve means "this is what we actually got when testing this type of engines". If you tested 20 engines, the shape of the "normaler" curve would all be a bit different.

 

[Alecvey8]

Ok, so here « Zuschaltung » is referring to, let's say the S/C « behavior » in relation with its hydraulic coupling and has nothing to do with MW50 « Injection circuit ».
I've been mislead by our discussion at home about translating that term, plus the fact they plot two curves only with MW50 use.
BTW my sentence about the existence of two MW50 injection « type » is also wrong ? If yes I'll update the post ...

 

[Alecvey8]

File V2 uploaded.
Still a lot of work to do
Comments or new sources appreciated

 

[Deleted member 68059]

There are a LOT of hard to find power curves in my book, a few of which (those which had to be printed in small size) are on my
website.

The Secret Horsepower Race: Image Archive - Calum Douglas

Here are some more to keep you busy, some of these are easy to find anywhere like 603A or 601E but the rest less so.

 

[Alecvey8]

Awesome info, thx a lot
I'll ask for your book as birthday's gift
back on your last document, I would say the curves illustrate « steig und kampfleistung » power, could you confirm please ?

 

[Deleted member 68059]

Awesome info, thx a lot
I'll ask for your book as birthday's gift
back on your last document, I would say the curves illustrate « steig und kampfleistung » power, could you confirm please ?

That would appear to be the case for the 601-E, yes. Therefore I imagine all the curves must be to the same standard for it to be meaningful, so yes, these
are not "emergency power" ratings.

 

[Alecvey8]

Thx a lot, and again for your awesome docs, will keep me busy for a while
Indeed I made the assumption on the 601E and 605A curves