Is somewhere a M-105(P/PF) and a M-107A Powercurve available??

[Knegel]

Hello,

iam a bit confused about the M-105/7 engine, in fact about almost all VVS Engine, cause i cant find a powercurve for this engine.
There are so many different datas available and nearly never i can find the altitude to the powerstatement and never i saw a statement for the time to overheat with the stated power.

Are there any VVS powercurves, similar like the DB601A or DB605A curves, with the 30min, 5min and 1 min setting available??

Thanks in advance,

Knegel

[niklas]

niklas

[Knegel]

Hello niklas,

do you know what setting is the 'Nennleistung' in relation to the DB601A powercurves, climb/combat(5-10min) or emergency(1-3min)??

Iam very interested in this cause i create FM´s for EAW and did stumble over the not fitting VVS climb vs speed datas.
I cant believe that a plane (Yak9U) have a Vmax of 533km/h 0m and 597km/h  in 4000m alt,  but only a middle climbratio of  1020m/min up to 5km alt.
For me it looks like they did use different powersettings for the climb and speed.

Is it realy possible that the M-105 had a max contunius of 990PS in 2000m ?? Thats exact the DB601A  30min power in 2000m.

How many octan the russian fuel had?? Oh man i dont know anything about russian technic.

And why is the this sheet in german language?

Thank you of course, thats a beginning!

Knegel

[gripen]

Good stuff Niklas!
A little quiz for gearheads: Why the stroke (Hub) is longer in the another cylinder bank (170mm/175mm)?

A hint: The reason is exactly same as in the case of the BMW VI.

gripen

[VO101_Isegrim]

For eliminating torque ? IIRC DB60xs did the same, but with different compression ratios,and same sized cylinders...

Kneagel, Russian avgas was 95 octane IIRC. Also, your data seem for basic, Yak-9, not later U model. Dont forget that speed requires clean lines in the first place, and Yaks were very clean, with advanced solutions like retractable, covered tailwheel. Climb requires just sheer power, great thrust weight ratios (and also good lift, ut that0s another matter). Drag doesn0t matter much, climb is a low airspeeds. And soviet engine outputs were not that good.

[gripen]

No. In the DBs stroke was same for both banks.

gripen

[VooDoo]

Tip: Try another numbers in the filename .

[Knegel]

Hello,

iam right, with the tought, that the M-105P and M-105PF(the curve above looks like the PF-1 or 2) are the same engine, one with emergency power (short duration) and one without?? Similar to the DB605A(1310PS) 1942 and the DM605A(1475PS) 1943??

And what you folks think about the M-107A-curve?? Is it similar to Start/Not(5min) or Steig/Kampf(30min)??

I think its Start/Not or the climbvalues of the Yak9U should be much better, but how would the Steig/Kampf-curve would look like?

If ithe assumption that the M-105PF is the M-105 with Start/Not setting, and if i compare and confer the power different between 5min(?) and  30min(?) settings from this engines, the M-107A Steig/Kampf power should maybe look like this:

M-107A 30min (?)

0m  ~ 1350PS
1700m  ~ 1420PS
2500m  ~ 1315PS
4500m  ~ 1360PS

But also with this powersettings the climbratio of the late Yak9´s , with 3200kg, seems to be to pretty poor.  The best climb to 5km alt  i saw, is 4,8 min but more often i saw 5,2 -5,8 min, how is that possible?? Of course not with the powersetting below!!
On the other hand i wonder how a plane that have a so bad climb can have a Vmax of 565-580km/h close to the ground, at least with 1550PS this seems to be pretty much.

Or had the russian planes terrible propellers, only made for highspeed, that would be the only explanation i know for the strange Speed/Climb/Power-relations(the early Spit1a without constant speed propeller had a similar bad climb in relation to its power and Vmax).


Any constructive comments are welcome!

Greetings, Knegel

[VooDoo]

VK-107A as installed in the first series of the Yak-9U was prone to overheating. Even with fully open radiators in level flight. So it was decided to limit usable powersettings. Only 3000 rpm in level flight and only 2800 rpm in climb. Later after fixing overheating problem "combat power" became avail. once again. 3200 rpm. Time to 5000 m for Yak-9U at 3200 rpm - 4,1 min. 4,8 min to 5000m - its time for VK-105PF2 powered Yak-9U.

[Knegel]

Hi Voodoo,

you did post when i was writing my post.

I dont understand russian(would need to wait for my wife to translate ), but  is the upper  curve like the M(VK)-107 emergency and the black like the M(VK)-107 Steig/Kampf??

If yes, the climbdatas of the Yak9U must be absolutly wrong or the wing produce negative lift.

With 3200kg and nearly always more than 1450PS up to 4000m alt, the Yak9U should have been a real rocket and with emergency it should have problems to stop until it reach the moon.

Do you ever saw climbtimes to 4km alt?? If i see the powercurve above 4km its no wonder that the climb to 5km is that bad.


Are you able to translate the text, or anyone else?

Greetings, Knegel

[VO101_Isegrim]

Perhaps these will help you, Knegel :





"Yak-9Y" is Yak-9U.

Have no idea about the exact conditions or powers used. I guess the extra power of the VK-107 was offset by the extra weight put on the Yak-9U compared to the basic Yak-9.

[VooDoo]

Damn... I cant post attachments... Anybody knows how it can be fixed ?

[Knegel]

he he, same time again.

I only saw the Yak9U prototype with 4.1min up to 5km alt,  the productionserie i have listed with 5min and more, 1st the 1946 Yak9U i have listed with 4,8 min.
So probably the 4.1min are with emergency!?

Since the VK-107 seems to lose roundabout 200PS between 4 and 5k alt and the black curve seems to be the 3000rpm curve, the 5min with 2800rpm to 5k alt slowly get more logical to me.

Iam right that for most wartime M(VK)-107A´s the black line is the Start/Not 3000rpm (5min ?) setting and a not shown line for 2800rp´s would represent the Steig/Kampf(30min?) setting??

Hi Isegrim, that are speed and climb sheets, unfortunately without enginedatas, i have them too, but without to know the overheattime and the enginesettingsetting etc such datas are not much worth.

Thanks anyway!!

Greetings, Knegel

[Knegel]

Same time again!

Do you mean the smilies??

There is a button below the postingwindow, there you can enable/dissable the, but in one of my earlyer posts my smilies also dont got posteted, they was enabled though. Maybe a short time messboardproblem?

Greetings, Knegel

P.S.: In this message should be 2 smilies.

[VooDoo]

Originally posted by Knegel

but  is the upper  curve like the M(VK)-107 emergency and the black like the M(VK)-107 Steig/Kampf??

Yes. But its not the climb power setting of the first series.

If yes, the climbdatas of the Yak9U must be absolutly wrong or the wing produce negative lift.
Whats wrong ? At full power it climbs to 5km in 4,1 min. Almost like Spit9.

With 3200kg and nearly always more than 1450PS up to 4000m alt, the Yak9U should have been a real rocket and with emergency it should have problems to stop until it reach the moon.
It had some problems with overheating. When it was fixed (or when it was ignored) it became a rocket. And it was nice dragster too - 175kmh speed gained in one minute from 0,7Vmax at 1000m.