What if Ostmark tooled the Jumo 213 instead?

[wiking85]

Flugmotorenwerke Ostmark ? Wikipedia
Historically the Ostmark aeroengine factory was built to produce the Jumo 222 engine, which never ended up being produced; instead in December 1941 it was ordered to tool for the DB603 engine, which wasn't really reliable until late 1943. As it was the factory never was able to produce many DB603s, in fact Daimler Benz lost control of the factory after their failure to use even a fraction of the theoretical 1000 engine per month capacity of the factory. What if instead of tooling for the DB 603 and transferring to Daimler's control, the factory stayed in Jumo's hands and was instead tooled to produce the Jumo 213? This engine was ready for serial production by Spring 1943, which put it ahead of the DB603 in terms of reliability. Historically this engine was not produced in significant numbers until 1944, due to bombing of Jumo's factories in Germany and the desire not to disrupt Jumo 211 deliveries. Here though there would be no need to disrupt 211 deliveries, so the lines could convert over in due time, while ensuring that Jumo 213s were produced in quantity by Summer 1943. Obviously it wouldn't be producing even half of the proposed 1000 units a month in 1943, as there were issues getting enough machine tools for any engine, let alone the DB603, but there would still be major capacity that could be utilized for the Jumo 213 in 1943 and 1944. It wasn't bombed significantly until July 1944 for the first time, which didn't really affect production, so until then and even after it could operate closer to capacity than most of Jumo's other production facilities, due to being outside the range of most bombing at the time. What would this mean for the Luftwaffe to have many more Jumo 213s in 1943 and in 1944, but less DB603s?

 

[tomo pauk]

The 'readiness for serial production in spring of 1943' does not mean that the engine itself would've been working as fine as engines produced in late 1944. DB considered the DB-603A as 'ready for serial production' in late 1942, but it took a better part of 1943 to iron out the bugs. Further, even the 213s produced in 1944 have had their issues:

Lutz Naudet placed these performance trials in context:

Now lets come to the interpretation as to why both Wk.-Nr. 001 002 generally fall short of calculated values. The first problem with all flight trials of Wk.-Nr. 001 002 is that they were done with the initial batch of production engines, which have well documented problems with supercharger performance. Those first production engines produced 60-100PS less than the book values used for performance calculations. The second problem is the engine gap. The drag data for the D9 most likely comes from scale models; those models will not have the engine gap as they are "carved out of one piece of wood". The scale model, therefore, has a smoother surface than the real airplane.

The 3rd thing is that Focke Wulf need to start the modification earlier, so we have the Doras in service before the Big Week. Such Doras will be good for maybe 410-415 mph in better part of 1944, or about as good as Fw-190A-6 or Bf-109G-6 (unrestricted DB-605A, no wing cannons). The A-6 will have twice the cannons, the G-6 will climb better, P-51B and P-47 are still 20-30 mph faster above 20000 ft, so the early Dora would have nothing new to offer.

source, chart

 

[wiking85]

The 'readiness for serial production in spring of 1943' does not mean that the engine itself would've been working as fine as engines produced in late 1944. DB considered the DB-603A as 'ready for serial production' in late 1942, but it took a better part of 1943 to iron out the bugs. Further, even the 213s produced in 1944 have had their issues:



The 3rd thing is that Focke Wulf need to start the modification earlier, so we have the Doras in service before the Big Week. Such Doras will be good for maybe 410-415 mph in better part of 1944, or about as good as Fw-190A-6 or Bf-109G-6 (unrestricted DB-605A, no wing cannons). The A-6 will have twice the cannons, the G-6 will climb better, P-51B and P-47 are still 20-30 mph faster above 20000 ft, so the early Dora would have nothing new to offer.

source, chart

Are you including the effects of MW50 and GM1 boost?

 

[davebender]

Ostmark plant was supposed to begin mass production during March 1942. Jumo 213 engine wasn't production ready.

You need to pick an engine which was ready or could have been made production ready by March 1942. DB603 and BMW801 are both possible.

 

[tomo pauk]

Are you including the effects of MW50 and GM1 boost?

The GM-1 boost would surely come in handy above 22-23000 ft. The problem is that I cannot find any reference that GM-1 was ever used with Jumo-213A. Corrections and suggestions are welcomed.
The MW-50 will provide extra power, but at altitude lower than the engine's full throttle heights. You might want to check out this graph - above 7000 m only small benefit in speed was noted if the 213A was using C3 fuel (line 2; instead of usual B4 fuel - line 1). With MW-50 used and B4 fuel (line 4) the gains above 6.5 km are negligible.
Since the main target for the LW were USAF heavy bombers and their escorts, operating from 25-30000 ft (7.6 - 9.1 km), neither C3 nor MW-50 will contribute much at that altitude. The historic D-9 (with engines working in good order, not early batches, and engine cowling fitted properly) was circa 30 mph slower at those altitudes than P-51 and P-47, the early Dora will suffer another 10 mph.

 

[davebender]

Ostmark engine plant was supposed to begin production during March 1942. What percent of Luftwaffe fighter aircraft were engaged with USAF heavy bombers during early 1942?

 

[wiking85]

The GM-1 boost would surely come in handy above 22-23000 ft. The problem is that I cannot find any reference that GM-1 was ever used with Jumo-213A. Corrections and suggestions are welcomed.
The MW-50 will provide extra power, but at altitude lower than the engine's full throttle heights. You might want to check out this graph - above 7000 m only small benefit in speed was noted if the 213A was using C3 fuel (line 2; instead of usual B4 fuel - line 1). With MW-50 used and B4 fuel (line 4) the gains above 6.5 km are negligible.
Since the main target for the LW were USAF heavy bombers and their escorts, operating from 25-30000 ft (7.6 - 9.1 km), neither C3 nor MW-50 will contribute much at that altitude. The historic D-9 (with engines working in good order, not early batches, and engine cowling fitted properly) was circa 30 mph slower at those altitudes than P-51 and P-47, the early Dora will suffer another 10 mph.

https://en.wikipedia.org/wiki/Focke-Wulf_Ta_152

The Ta 152 H-1, with the Jumo 213 E engine, was among the fastest piston-engined fighters of the war, capable of speeds up to 755 km/h (472 mph) at 13,500 m (41,000 ft, using the GM-1 nitrous oxide boost) and 560 km/h (350 mph) at sea level (using the MW 50 methanol-water boost).[6] To help it attain this speed, it used the MW 50 system mainly for lower altitudes (up to about 10,000 m/32,800 ft) and the GM-1 system for higher altitudes, although both systems could be engaged at the same time. The Ta 152 was one of the first aircraft specifically designed to employ a nitrous oxide power boost system.

 

[tomo pauk]

You've mixed up the Jumos.
The 213A was a single-stage engine, used on Fw-190D-9 and some Ju-88G night fighters (maybe bombers, I'm not certain) - in production from late 1943 for the Ju-88 NFs? The Jumo 213E was a two-stage engine with inter-cooler, used on Ta-152, produced in small quantities in 1945. There was also Jumo 213F, a two stage engine without inter-cooler, used on Fw-190D-12. The D-11,-12 and -13 were rare birds, produced in 1945. The -E was more powerful than -F, but the -F was less draggy (no intercooler).
You can check this: here and here.
The difference in power was substantial, between single- and two stage engines, especially above 7.5 km (25000 ft); never mind the line named 'Jumo 213E C3', I'm not sure that 213E ever flew with C3 fuel.

 

[tomo pauk]

Ostmark engine plant was supposed to begin production during March 1942. What percent of Luftwaffe fighter aircraft were engaged with USAF heavy bombers during early 1942?

We're discussing Jumo 213 here, and when that engine come into fruition (1944), you can bet that the best use of the 213s would've been to install them into a suitable fighter airframe to combat that threat. Before late 1943, the Fw-190A-5/A-6 were just fine (even the 2-engined heavy fighters), but the advent of the long range escort provided by high performance fighters caught the LW with their pants down re. high performance fighter of their own.