Bf-109 vs Spitfire vs Fw-190 vs P-51

[renrich]

Chris hits the nail on the head with his last statement. To me, still, in order to be judged as a significant AC in a war, an airplane needs to be put into production, with bugs ironed out and have a significant combat record. Either that or be a revolutionary design like the ME262. I have asked this question several times and no answer so this time I am asking Soren, the big kahuna on the wunderflieger, TA152, how many TAs were ever operational and how many kills did it have and if possible, against what AC. As far as a "big" radial engine is concerned like the R2800, well, you take that engine, stick it in as small an airframe as possible and you have an airplane like a Corsair, that can carry a lot of fuel, get off the ground fast, is very survivable, can carry a big ordnance load and has a lot of stretch in the design. Or you take the same engine and stick it into an even smaller airframe and have a shorter ranged fighter with a smaller ordnance load but up to about 20000 feet can outperform any piston engined fighter ever built, the F8F.

 

[Glider]

The -57 and the Centaurus V have a very high power output, but they are rather heavy and bulky. .

Re the ref to being Bulky. The attached photo shows a Hercules engine and a Centuraus. There isn't a lot in it.

 

[Glider]

Sorry everyone I don't know what happened as I did resize the photo.

 

[Soren]

the merlin also had 4 valves a cylnder

Yes and so did the DB-605, but the Jumo 213J is a 35 Liter engine and is lighter at 700 kg dry weight, and take off power was 2,000 PS.

 

[Soren]

Renrich,

The Ta-152H is credited with 12 kills for no losses, all kills were enemy fighters.

 

[DerAdlerIstGelandet]

I have asked this question several times and no answer so this time I am asking Soren, the big kahuna on the wunderflieger, TA152, how many TAs were ever operational and how many kills did it have and if possible, .

I do not have hard fact numbers but I believe that there were between 65 and 72 production aircraft that were delivered to the front line units out of aprox 150 that were built.

That fact though is, the Ta 152 was in production.

My understanding however though is that the aircraft did have some bugs, these bugs certainly would have been worked out with a bit more time.

If I am correct JG 301 never had more than 15 to 20 operational at any given time.

This information is taken from a hodgepodge of sources though and I can not verify its reliability.

 

[Soren]

How long are we with the comparison so far Bill ? Any last things we need ?

 

[davparlr]

Davparlr,

Your comparison is good but remember you're comparing the Ta-152H with the Jumo 213E engine. At the time the P-51H would've arrived the Ta-152H would've been equipped with the superior Jumo 213EB engine which featured much better high alt performance.

On top of that the Jumo 213J was in development and would've followed shortly. This engine had four valves pr. cylinder, making it the most advanced and efficient piston engine out there.

Punch and counterpunch. The story of WWII technical development. In production, P-72, airspeed at 3200 ft., 480 mph. Killed by lack of need and advent of jets.

 

[kool kitty89]

The XP-72, first prototype with 4-blade paddle prop, managed 490 mph at
25,000 ft, I haven't seen figures for higher altitudes, but this may be the crit
altitude for the a/c. (could have changed with a larger turbocharger)

The XP-47J's fastes speed was 507 mph at 32,000 ft.

The XP-47J was the first piston engined aircraft to exceed 500 mph. (iirc the
record held for piston/prop aircraft, until the Bearcat's record breaking flight
in the 80's)

 

[Soren]

The XP-72 was a prototype a/c Davparlr, only two were ever built.

Furthermore it would've never entered mass production even with interest as the jet engine had by that time already established its superiority, one of the reasons behind some the Ta-152's development delays. By mid 44 the Germans were after-all pushing 900 km/h with service jet a/c, and over 1,000 km/h with finished prototypes.

 

[pbfoot]

Yes and so did the DB-605, but the Jumo 213J is a 35 Liter engine and is lighter at 700 kg dry weight, and take off power was 2,000 PS.

ok then why mention the 4 valves when in fact the merlin is an earlier engine

 

[Soren]

ok then why mention the 4 valves when in fact the merlin is an earlier engine

Because the extra valve pr. cylinder increased take off power to 2,000 PS vs the earlier 1,750 PS for no weight increase, giving an unpresidented power to weight ratio of 2.82 hp/kg.

 

[kool kitty89]

Soren, don't forget though when comparing dry weights (and subsequent p/w
ratios), that can show discrepancies in comparisons, particularly in this case
where a radial engine would lose out by dry weight, but win (or be very
close) in operational configuration. (the liquid cooled engines requiring added
weight for coolant, and in particular the external cooling system and radiator)


In operational circumstances, I think the R-2800-57 would be prety close to
equal to the Jumo in terms of power/weight.

 

[claidemore]

Yesterday the score was 11-0 for the Ta152, today it's 12-0?
In any case, the Stabstaffel/JG301 pilots were all hand picked aces, many of whom had earned the Knights Cross, and I would give much of the credit for that success to the men themselves. This was really a dream team as far as fighter units go.

On the topic of mis-identifying the Ta152, 109s from JG310 itself attacked the first operational sortie of Ta152s. Nobody knew what they were.

As for valves, both the Sabre and Centaurus were sleeve valve engines. I believe the Sabre is the only WWII aircraft engine that delivered greater than 1 horsepower per cubic inch of displacement. (one test R2800 matched it's displacement with 2800hp) Saber V engines with 2238 cu in displacement gave 2400 hp (2.2hp/kg in a production engine which actually saw considerable service and which could be boosted to 3000 hp in emergencies) Saber VII gave 3500 hp (3.2 hp/kg). Later test engines ( production Saber engines used in tests) were run up to 4000hp. (5500 according to some sources).

The Centaurus engine gave 2000 hp right from the start, eventually achieving 3200 hp (2.6hp/kg).

Also, I believe the Jumo 211 weighed 720 kg, but the 213 weighed 920-940 kg. That makes it 2.1 hp/kg.

 

[kool kitty89]

The R-2800-57C had a WEP of 2,800 hp at 2,800 rpm. (in operational conditions)

However, in testing: P-47M

During durability testing of the C series R-2800 by Republic, it was
decided to find out at what manifold pressure and carburetor temperature
detonation could be induced. They ran the engine at extreme boost
pressures that produced 3,600 hp! But wait, it gets even more amazing. They
ran it at 3,600 hp for 250 hours, without any failure! This, with common
100/130 avgas. No special fuels were used. Granted, the engines were
completely worn out, but survived without a single component failure.

And don't forget about the Merlin, it exceeded 1hp/in^2 by a good margin on production versions. (over 1.25 on production models)
(the V-1710 did as well, with 2,300 hp on -non-turbo-compound- production models by the end of the war,
but the only such to see service was on the P-63C, 1,800 hp with water injection.
and on the P-38L's engine made almost this much with 1,725 hp at 64" Hg, albeit with turbocharging.
Some racing versions of the V-1710 were tuned as high as 4,000 hp)

And long before that ther was overboostng of the P-40D/E/K's engines: http://www.raafwarbirds.org.au/targetvraaf/p40_archive/pdfs/Allison 1710-39 abuse.pdf

 

[Kurfürst]

Soren, don't forget though when comparing dry weights (and subsequent p/w
ratios), that can show discrepancies in comparisons, particularly in this case
where a radial engine would lose out by dry weight, but win (or be very
close) in operational configuration. (the liquid cooled engines requiring added
weight for coolant, and in particular the external cooling system and radiator)

Very much true. However radials usually also have a much larger frontal area, thats where inlines takes advantage.

In operational circumstances, I think the R-2800-57 would be prety close to
equal to the Jumo in terms of power/weight.

Hmm, how about that turbocharger system weighting what, half a ton..? Its also part of the whole powerplant package.

IMHO powerplants need to be compared as a whole package. Engine weight, dimensions, oil/coolant cooling and intercooling losses (raditor drag and weight), liquids weight, boosting systems, aux. equipment, fuel needed for given excess thrust for given period etc.

HP/displacement is the most irrevelant value of all. Take the Sabre for example - it weights a ton and its frontal area is greater than that of a radial engine`s...! Technically its brillant, for practical applications, its just overcomplicated and impractical.

 

[kool kitty89]

You're right on the turbocharger, but I was talking about the engine its self (though the P-47M/N were the only production applications iirc). And the engine may have been capable of sufficient boost w/out the turbocharger (integral neutral blower) to acheive that power, albeit at very low altitude. (and I don't know if a 2-stage, or other variable speed, mechanically driven supercharger was fitted to this specific engine model, and if it had some of the power would get drawn off at higher altitudes)

Also the 720 kg figure isn't right for the Jumo 213. (that's the weight of the later 211's iirc) The 213E should weigh around 940 kg, similar to the DB 603.



And on the sabre, while it was pretty wide, at 40" it's still much narrower than comparable radials. (the only military radial of the period smaller would be the tiny Gnome-Rhone 14M, though the Bristol Taurus was almost that narrow)


And also liquid cooled engines tended to be more fuel efficient than the radials.




Yes the powe/displacement argument is a bit odd. (I'm not sure why it started here) And technically speaking you can get a higher power/displacement ratio on any of these engines by increasing RPM and boost (given high enough octane and/or water injection) to the point of the engine's structural limitations. (which are often subsequently increased in development)


However, as I believe Soren mentioned on another thread recently, the increase in RPM and (particularly, except for turbocharged engines) in boost increases specific fuel consumption. And if you can get a large displacement engine of similar power, dementions, and weight as a smaller displacement one the larger displacement engine will generally be more advantageous. (and the German engines had the direct fuel injection as well)
I believe Soren made a comparison between the German and French (and Russian; copies from French, or developments of German engines) higher displacement engines vs the contemporary US/UK engines.

 

[davparlr]

Davparlr,

Your comparison is good but remember you're comparing the Ta-152H with the Jumo 213E engine. At the time the P-51H would've arrived the Ta-152H would've been equipped with the superior Jumo 213EB engine which featured much better high alt performance.

The XP-72 was a prototype a/c Davparlr, only two were ever built.

Furthermore it would've never entered mass production even with interest as the jet

Several sources indicate that 100 P-72s were ordered into production only to be cancelled because of changing priorities and the advent of the jet which would have been a wise move for Germany if only they could protect their airspace.
You tend to represent could-have-been German aircraft as viable arguments but dismiss allied could-have-been aircraft.


The fact of the matter is that, if there were no jets and the war continued, none of the advanced German prop planes would have flown very long without significant challenge, just like it had always been.

 

[davparlr]

Very much true. However radials usually also have a much larger frontal area, thats where inlines takes advantage.

That didn't seem to be a problem with the FW-190, P-47, F4U, or Rare Bear, the worlds fasted propeller driven aircraft.

 

[KrazyKraut]

The fact of the matter is that, if there were no jets and the war continued, none of the advanced German prop planes would have flown very long without significant challenge, just like it had always been.

The fact of the matter is there were jets. By the time the XP-72 flew for the first time, even USAAF jet programs had completed their first flights, which I guess contributed to the decision not to pursue the project. Jets were simply the better solution to the problem.

That didn't seem to be a problem with the FW-190, P-47, F4U, or Rare Bear, the worlds fasted propeller driven aircraft.

The point was: Simply quoting displacement / hp doesn't tell you everything about the respective aircraft performance nor does it translate into technical superiority.