BMW801D2 Horsepower at 1.62ata

[MiloMorai]

It pays to visit the LEMB

Sea level:

1660 HP @ 2700 rpm/1.42 ata
1890 HP @ 2700 rpm/1.58 ata <- maximum used

300 m:

1670 HP @ 2700 rpm/1.42 ata
1900 HP @ 2700 rpm/1.58 ata <- full throttle height :-)

2800 m:

1580 HP @ 2700 rpm/1.42 ata
1840 HP @ 2700 rpm/1.65 ata <- note higher boost

http://p069.ezboard.com/fluftwaffeexperten71774frm9.showMessage?topicID=291.topic

by the same person, Henning

"It can be determined graphically from the engine chart you posted.

The speed chart shows that the full pressure heights at increased boost are 700 m for low gear and 5500 m for high gear at top speed. One can simply extend the "drop off" legs of the high-speed power graph to this altitude to get the power output."

Now Col Klink's lapdog, that quote is from your own post. You should keep your mouth shut. What did I suggest?

Nice to see Crunpp that you finally found a reference to the 1.32 restriction.

[MiloMorai]

Technical description No. 284 (for the A-8)

Weight distribution (in kg)

Fuselage - 345.2
Undercarraige - 258.3
Control surfaces - 120.8
Flight controls - 32.3
Wing assembly - 475.0
Powerplant - 1661.3
Standard equipment - 248.1
Permament accessories - 27.4
Additional accessories - 319.3
Paint - 2.0

Empty weight - 3489.7 > 3490

Pilot, parachute, flying gear - 100
Normal fuel - 410
Aux. fuel tank(115l) - 90
Lubricants - 50
Ammo(MG131 - 2x75) - 77
Ammo(MG151 - 2x250) - 110
Ammo(MG151 - 2x140) - 64

Useful load - 901.0


Flying weight - 4391.0 > 4400 (901.0 + 3490)

[GScholz]

The entire post:

Hi Kutscha,

>What was the power output at 1.62ata?

I've got a German power chart indicating the following high speed powers for the BMW801D:

Sea level:

1660 HP @ 2700 rpm/1.42 ata
1890 HP @ 2700 rpm/1.58 ata <- maximum used

300 m:

1670 HP @ 2700 rpm/1.42 ata
1900 HP @ 2700 rpm/1.58 ata <- full throttle height :-)

2800 m:

1580 HP @ 2700 rpm/1.42 ata
1840 HP @ 2700 rpm/1.65 ata <- note higher boost

This was a BMW801D-2 as used in the Fw 190A-5 prototype.

However, I recently discovered that German engines can differ considerably even under the same designation (the DB601A-1 did!), and it seems to be the same for the BMW801D-2.

Comparison between high speed data from two different BMW801D-2 engine charts for normal boost:

Sea level:

a) 1660 HP @ 2700 rpm/1.42 ata
b) 1740 HP @ 2700 rpm/1.42 ata

Low gear full throttle height:

a) 1710 HP @ 2700 rpm/1.42 ata <- 1.4 km
b) 1770 HP @ 2700 rpm/1.42 ata <- 1.4 km

High gear full throttle height:

a) 1420 HP @ 2700 rpm/1.42 ata <- 6.5 km
b) 1490 HP @ 2700 rpm/1.42 ata <- 6.7 km

The graph from American tests gives yet other data:

1660 HP @ sea level <- as a)
1760 HP @ 6000 ft <- as b)
1600 HP @ 22000 ft <- more than a) or b)

Conclusion? I'm confused :-)

Regards,

Henning (HoHun)

[Crumpp]

Now Col Klink's lapdog, that quote is from your own post. You should keep your mouth shut. What did I suggest?

You've got nothing useful to contribute Milo.

At least nothing that is worth your crappy attitude.

Crumpp

[MiloMorai]

Originally posted by Crumpp
You've got nothing useful to contribute Milo.

At least nothing that is worth your crappy attitude.

Crumpp

Another slanderous assault.  

to paraphrase you crumpp What has this to do with finding the power output at 1.65ata?

Oh, and I did contibute, for I corrected you after letting you run with it, that the boost is 1.65, NOT 1.62 Now did you do the same with the 1870 - 1780 @1.42? We all make errors crumpp, so why cop the attitude? I also gave a weight breakdown for the A-8 (from a LW doc) and some HP numbers.

It is you, crumpp, that is doing any of the de-railing of your thread.

[Crumpp]

Number one Milo,

You don't point out mistakes - you belittle.  Got no time for that.

I have TOLD you at least 4 times - The stuff is copyrighted and Copyrighted in the US against electronic distribution!!  I for one don't want to see HTC embroiled in a lawsuit AND would like to see the Luft-archive stay in business.  So if you want to see the stuff I am looking at buy the material.

http://www.luftfahrt-archiv-hafner.de/

If buy it on disk it comes as password protected secure pdf documents.  I am waiting on word from Luft-archive if they will give me permission to share it with Pyro.  If not I will have to mail him the manuals.  How many times do I have to say it?


This is why you have nothing useful to contribute. Not only do I have to tell you 4 times why I can't post it.  Your first four post's where attacks on the 1.42ata hp rating I posted.  What does HoHun's post say "Horsepower rating vary wildly".  It is confusing.  Not only are the units of measure different but you have to know the altitude and whether the figure was adjust for velocity at speed.  When you have that answer, after posting on the LEMB, instead of full disclosure on the issue you choose to post ONLY the parts which support your argument.  You also don't say that those are CALCULATED figures by another player from a WB forum.  Gscholz already posted them.

Now I politely say "Thank you for your time.  Please move on."  You lend an adversarial air to any thread you contribute too.

Now does anyone know of official sources for the 1.65ata? I have emailed the Luft-archive and the "White 1 Foundation".

Crumpp

[VooDoo]

I've got a German power chart indicating the following high speed powers for the BMW801D:

Rammed power ?

[MiloMorai]

LOL crump, I asked for clarification on the 1.42 power output. "Your first four post's where attacks on the 1.42ata hp rating I posted." Attacks?? for sure you be dillusional. It was you who copped the attitude and went on a rant for such a simple question. Are you that insecure that anyone who questions you is adversarial? Notice that none of the other posts say 1870hp @ 1.42.

Then you say, "I've got several NACA graphs. All show the standard 1800hp at 1.42ata NOT 1740hp." Does this not raise any question in your mind? Where you got the 1740 from is anyones guess and 1800 is closer to 1780 than the 1870.

Did I ask you to post any scanned data? NOPE!! Must have been your snotty superiority complex making you dillusional, still.

The link to the LEMB was there for any who wanted to see the WHOLE thread. Now what is this 'arguement' you claimed I have. More dillusion on your part. "I've got a German power chart indicating the following high speed powers for the BMW801D:" via Col Klink's lapdog, quoting Henning. Now where does Henning say they are calculated for what I copied/pasted?

What an insecure pompous jerk you are crumpp, so .


You keep parrotting that injection cools the heads. The injection kept the f/a mixture temperaure down when over boosting (gas compression = gas temperature increase). This stopped pre-ignition of the mixture in the combustion chamber. Pre-ignition would raise the temperature of the engine. The heads are not cooled, only kept at a safe operating temperature for awhile and hence the time restriction on injection use.

Have a nice day now.

[Crumpp]

I've got a German power chart indicating the following high speed powers for the BMW801D:

Yes Voodo.  Pretty sure it's horsepower at air speed velocity not rammed.  Most of the aeroengines in WWII had superchargers which did ram the intake.

This is refering to the actual Horsepower in the Air at a specific altitude and airspeed.  It actually lower than Horsepower on a benchtest.

You keep parrotting that injection cools the heads. The injection kept the f/a mixture temperaure down when over boosting (gas compression = gas temperature increase). This stopped pre-ignition of the mixture in the combustion chamber. Pre-ignition would raise the temperature of the engine. The heads are not cooled, only kept at a safe operating temperature for awhile and hence the time restriction on injection use.

In one sentence - It kept the heads cool.
Another way to put it - It cooled the heads.
Another way - It kept the heads from overheating.

Only in the A5 series was there a time limit placed on 190's with C3.  In the A7 it was changed to unlimited.

Crumpp

[VooDoo]

Pretty sure it's horsepower at air speed velocity not rammed
Didnt understand. I thought "rammed" mean that its static power + gain from higher air pressure at high speed.

[GODO]

The following allied document dated March 24 1945 indicates 1870Hp for 1.65 ata at sea level (360 mph). Note that 1.65 ata is referred for both, high and low blower, that may be a mistake in the document. The document also indicates that the pressure of the C3 spray nozzle can vary from 18 to 25 lb/sq/in while air pressure remain fixed at 1.65 ata.

BMW 801D 1.65 ata

[Crumpp]

Hey GODO,


Things that you go MMMMMMMMMMMM.  I am trying to get a copy of HoHuns Luftwaffe document.  I am wondering if this is a D or a D2.

That would explain the Horsepower difference's between the NACA graph / Luftwaffe Document HoHun has which say 1700 - 1800 range at 1.42ata and the test you posted?

Other possibility is wear and tear on the motor.  Just speculating.  Got any ideas?

Crumpp

[VO101_Isegrim]

Originally posted by GODO
The following allied document dated March 24 1945 indicates 1870Hp for 1.65 ata at sea level (360 mph). Note that 1.65 ata is referred for both, high and low blower, that may be a mistake in the document. The document also indicates that the pressure of the C3 spray nozzle can vary from 18 to 25 lb/sq/in while air pressure remain fixed at 1.65 ata.

BMW 801D 1.65 ata

Yeah, I know that one, but think there are inaccuracies in it.

Going from 1.42 to 1.65 ata should yield a lot more power than only 1870... power increase is usually linear with boost increase, so...

If we raise boost by 16.2%, then our power increase should be very much the same, ie. 1800PS x 1.16 = 2088 PS. Very close to the published 2100 PS.

However if we only raise the boost to 1.58ata, similialry that would be 2002 PS.

I tend to believe 1.65ata was high-sc gear only, and hence comes a confusion in the doc, probably they give 1870HP/SL/1.65ata, however it probably refers to 1.65ata in high gear, at rated altitude, and not SL.


Which is why I am curious to see some original source on that.

[Crumpp]

I tend to agree with that Isegrim.  I am trying to get a copy of Hohun's Luftwaffe document to prove it.

It seems the Spit MkIX and the 190 had very similar boost and Horsepower increases.  The FW-190 was always thousands of pounds heavier than the Spit.

That info comes from the RAF documents on the Tactical Trials conducted on Fabers A3.  I'm gonna get some better reference material on the Spitfire.  It is just as confusing as any LW fighter.

The weight in the 190 shot up but not nearly as dramatically as one might think.  Infact the Power to Weight ratio in the FW198A8 at 1.58ata was only hundreths of kilo off of the 190A3's Power to weight ratio.  In fact it seems the Spitfire IX with +25lbs boost was fitted with an extra internal auxiliry tank very similar to the 190A8's 115 liter aux tank.  Both tanks were optional, at least the Luftwaffe aux tank was and I assume the Spit tank was too.


The FW190A8 fully loaded was 294kg's heavier than the 190A3.  With it's power to weight that would have meant an increase in dive accelleration, Dive Speed, and zoom climb.  The level accelleration would have been comparable to the A3's.  Turn radius would have suffered some but then turning was never a 190 strength.  All with a much better armament package.

Overall the 190A8 would have been an improvement over the 190A3 in the 190's fighting qualities.



Crumpp

[niklas]

Originally posted by Crumpp
IIn fact it seems the Spitfire IX with +25lbs boost was fitted with an extra internal auxiliry tank very similar to the 190A8's 115 liter aux tank.  Both tanks were optional, at least the Luftwaffe aux tank was and I assume the Spit tank was too.

Crumpp

I´m convinced that the aux tank for the fw190 was absolutly necessary when the extra boost was installed, and not optional. The fuel consumption was very high with the extra boost, so imo the 115l aux tank was more likely a coolant tank rather than a fuel tank. Of course it could be used as a fuel tank too (at least i think so), but without it the range would have been dramatically reduced when using the extra boost.

niklas