Dec 1941 RLM decision. Produce BMW 801. Cancel Jumo 222.

[davebender]

1,088kg. BMW801 engine. Dry weight.
1,084kg. Jumo222 engine. Dry weight.
…..Dry weight was almost identical.

1,677hp. BMW801 engine. C3 fuel.
2,500hp. Jumo 222 engine design power. B4 fuel.
…..You could derate early production Jumo 222 engines all the way down to 1,700 hp and they would still be as powerful as the BMW 801.

End of March 1942.
Ostmark Engine Plant stage 1 construction completed.
Designed to produce 500 Jumo 222A engines per month.
A possible future expansion (stage 2) would have doubled production to 1,000 Jumo 222 engines per month.

IMO the 24 Dec 1941 RLM decision to cancel Jumo 222A engine production was one of the most bizarre of the war. Every aircraft powered by the BMW801 engine would have performed better powered by the Jumo 222A even if early production Jumo 222 engines had to be derated. The brand new Ostmark engine plant could have been producing 500 Jumo 222 engines per month by the end of 1942 with plans for future expansion.

 

[Tante Ju]

On a liquid cooled engine you also have serious amount of weight from coolant liquid and raditors, piping, and more drag from these installations.. on a radial like BMW 801, none... so dry weight alone is a bit misleading.

 

[davebender]

So is the argument that radial engines don't require weight for a cooling system.

The Fw-190A had the nose extended twice (once prior to mass production) in order to provide adequate cooling for the BMW801 engine. Each nose extension added weight to the aircraft and affected aircraft handling.

 

[Shortround6]

The Jumo 222 was a rathole project. All the time and money failed to produce a useable engine out of nearly 300 made. Part of this was due to constantly changing requirements but part was due to an overly ambitious basis. Germans would have dome better to use the factory at Ostmark to make Jumo 211s or 213s and take the spent on the 222 to develop that series of engines.

The US had it's share of rathole engines. Both the US and the British introduced several engines into service that were "READY" that turned out to be nothing of the sort.
Germans mass producing Jumo 222s might have been a real benefit to the Allied war effort.

 

[Shortround6]

So is the argument that radial engines don't require weight for a cooling system.

The Fw-190A had the nose extended twice (once prior to mass production) in order to provide adequate cooling for the BMW801 engine. Each nose extension added weight to the aircraft and affected aircraft handling.

The cooling system for a Merlin or Allison started at 300lbs for the low powered ones and went up. Cooling system for a 222 could run 500-600 pounds. The entire fuselage of the Fw 190 might not have weighed 600pounds.

 

[DonL]

I have a significant problem with this headline and the suggestion!

The development of the BMW 801 and the development of the FW 190 both since 1938 had no single influence of other RLM projects and absolutley no influence of the Ostmark engine factory!

The BMW 801 with the FW 190A was a project to get the BMW and FW company in production (major) and the decision was made 1938!

1938: Production and development:
Messerschmitt had the Bf 109/Bf 110 and was developing the Bf 210 since 1937 / Bf 109 and Bf 110 major production
Junkers had the Ju 87, Ju88, Ju 288 (Bomber B), Ju 90 and the Jumo 211 and the Jumo 222 (BomberB)/ Ju87, Ju88, Jumo211 major production
Heinkel had the He 112, He 100, He 111 and the He 177 (Bomber A)/ He 111 major production
Dornier had the Do17, Do 215 and Do 217 / Do 17 and Do 215 major production
DB had the DB 601, DB 606 (BomberA) and DB 604 (BomberB)/ DB 601 major production

FW had the FW 187, FW 200, FW 191(BomberB), FW 189 but no major production
BMW had only the BMW 132 engine in production

The decision was absolutely ok to bring both companys in the production game

Both the advertisement of the Bomber B ( Jumo 222, DB 604) and the advertisement of the Bomber A with coupled engines (DB 606) were binding major development capacity of both engine companys, this development capacity was lost in the development time of the Jumo 213 and the DB 603. Also the abrupt change of the the Jumo 222 to the DB 603 at the engine factory ostmark was controprodctive but all this had nothing to do with the BMW 801 (resources, production and development capacity)

So there was in fact and reality no choose between the BMW 801 and the Jumo 222!

 

[Siegfried]

On a liquid cooled engine you also have serious amount of weight from coolant liquid and raditors, piping, and more drag from these installations.. on a radial like BMW 801, none... so dry weight alone is a bit misleading.

The use of an integral radiator as was common on Jumo engines would seem to minimise these weight costs: for instance there are no bulky pipes running through the fueselage into the wings. Furthermore, AFAIKT Jumo engines used a warmtauscher (heat exchanger) which provided oil cooling (and intercooling) through the one radiator. Finally the wet weight of an radial (with oil and oil cooler) I belive is also considerable. As much as 50% of the heat of a radial engine can come out of the oil cooler. They might be best called 'oil cooled' engines.

 

[Siegfried]

The cooling system for a Merlin or Allison started at 300lbs for the low powered ones and went up. Cooling system for a 222 could run 500-600 pounds. The entire fuselage of the Fw 190 might not have weighed 600pounds.

Assumming a 250kg then the wet weight of the Jumo could be 1330kg versus 1080kg dry for the BMW.
This means the Jumo 222 would need to develop 1460/1080 or 1.23 times the power; about 2090hp to match the radial power to weight ratio.

Add in oil and oil coolers to both engines and the gap closes somewhat so the jumo 222 could be derated to less than 2000hp and still be competitive in terms
of power to weight ratio; all on 87 octane and less drag and more power. I am not sure of what weight needs to be factored in for oil and oil coolers.

 

[davebender]

I don't have a problem with continuing development of the BMW801 radial engine. But if RLM must retool a factory for DB603 engine production it should be something other then the Ostmark Jumo 222 plant.

 

[DonL]

I don't have a problem with continuing development of the BMW801 radial engine. But if RLM must retool a factory for DB603 engine production it should be something other then the Ostmark Jumo 222 plant.

You are know in a dead circle!
The production of the BMW 801 had started in spring/summer 1941, what do you think will happen if you retool the BMW company from radial to inline engines at autum/winter 1941?

The german aircraft industry had not the capacity to all this projects.
If you want to have the DB 603 and Jumo 213 ealier you must cancel or have no advertisement of the Bomber B (Ju 288, Jumo 222, DB 604) and the advertisement of the Bomber A should be with normal engines.

All this saved money and the development time you can fund in a extra engine factory (an other one extra to ostmark) and you can produce an develop the DB 603 and Jumo 213 ealier and faster.

But the Bomber B, Jumo, 222/DB 604 and the DB 603/Jumo 213 are in direct dependence, you can't have it both from money, production capacity and development capacity!

 

[davebender]

Not exactly. The BMW 801 engine was produced in three large plants.
U.S. Strategic Bombing Survey Aircraft Division Industry Report
Allach-Munich. Mass production from fall 1940.
Klockner. Mass production from Jan 1942.
Spandau. Mass production from Jan 1942.
One of the BMW plants (either Klockner or Spandau) could be converted to DB603 production during 1942.

The Jumo 211 engine was also produced in three large plants.
Junkers Engines - Jumo 211
Magdeburg. From July 1937.
Kothen. From 1938.
Leipzig. From 1942.
Germany had a surplus of Jumo 211 engines by 1943. So the Leipzig plant probably wasn't needed and could have been retooled for DB603 production.

Now we've got two large plants retooling for DB603 engine production during 1942. And Jumo 222 engine production still begins at Ostmark on schedule during March 1942.

 

[wuzak]

As far as I am aware the Jumo 222 was a troublesome engine which needed a lot of work before it was ready for production.

Detuning early series to overcome reliability issues sounds a lot like what heppened to the Vulture.

The Daimler-Benz DB604 was cancelled in 1942 IIRC. Does anybody know the reason why?

Was it unreliable? Fell foul of production priorities?

The DB604 was only a little bigger in capacity than the DB603 (46.3l vs 44.5l) but was more powerful. It did weigh about 160kg more.

 

[wuzak]

On a liquid cooled engine you also have serious amount of weight from coolant liquid and raditors, piping, and more drag from these installations.. on a radial like BMW 801, none... so dry weight alone is a bit misleading.

The only thing I would say here is that aircraft with liquid cooled engines tended to be faster even with less power (assuming a design optimised for the engine).

 

[davebender]

Jumo 222 and DB604 were competing for the same engine contract. I'm under the impression the Jumo 222 won the competition, which is why the new Ostmark engine plant was tooled for the Jumo 222 rather then the DB604.

For all practical purposes the DB604 engine program ended when Ostmark was tooled for the Jumo 222. Just as the Jumo 222 program ended for all practical purposes when Ostmark was retooled for the DB603 engine.

 

[Shortround6]

I don't have a problem with continuing development of the BMW801 radial engine. But if RLM must retool a factory for DB603 engine production it should be something other then the Ostmark Jumo 222 plant.

No, even if the Ostmark plant was retooled for Hirth 4 cylinder air cooled trainer the engines the Germany would have come out ahead.

For the number of engines made compared to the number of air frames flown flown with them the Jumo 222 has got to be near the top of the list in most engines made per air frame flown. This should tell us something. With 270-289 made (depending on source) how many airframes actually made it into the air powered by Jumo 222s even as testbeds?

I am not trying to pick on the Germans here, the Americans built a factory to make the Continental 1430 engine, it wound up making radials and finally a few hundred Merlins despite the 1430 engine going through some 15 or 16 variations including flat (opposed), up right V and inverted V. It only ever powered a few prototypes but I doubt that the US built almost 300 of them. I feel that somewhere there is/was somebody who claimed it was canceled "just when ready for production"

 

[davebender]

how many airframes actually made it into the air powered by Jumo 222s

Retooling the Ostmark engine plant to produce DB603s destroyed several promising German aircraft programs.

Bomber B program aircraft.
Do-317.
Ju-288.
Fw-191.

Do-435 night fighter.
He-219 night fighter.

Dr. Tank was designing a Fw-190 variant powered by the Jumo-222.

Ju-488 heavy bomber.
One of the He-177B prototypes was supposedly fitted with Jumo 222 engines.

There are probably more if you want to spend time searching.

 

[Siegfried]

As far as I am aware the Jumo 222 was a troublesome engine which needed a lot of work before it was ready for production.

Detuning early series to overcome reliability issues sounds a lot like what heppened to the Vulture.

The Daimler-Benz DB604 was cancelled in 1942 IIRC. Does anybody know the reason why?

Was it unreliable? Fell foul of production priorities?

The DB604 was only a little bigger in capacity than the DB603 (46.3l vs 44.5l) but was more powerful. It did weigh about 160kg more.

The DB604 had inferior cruising power to the Jumo 222, apparently this was its only downside. The engine actually developed a lot of technology that served Daimler Benz well in the post war periode (in piston design)

 

[davebender]

Daimler-Benz in the Third Reich - Neil Gregor - Google Books
Daimler-Benz management placed great emphasis on positioning the company so it would remain profitable in the post-war world no matter which side won. That attitude was a major cause of friction between Daimler-Benz and RLM.

 

[Jabberwocky]

BMW 801 'power egg' weight: 1140 to 1250 kg, depending on aircraft installation.

Jumo 222A Series I 'power egg' weight: 1830 kg. Later installations with more complicated supercharger set-ups were probably heavier.

 

[Jabberwocky]

Retooling the Ostmark engine plant to produce DB603s destroyed several promising German aircraft programs.

It was more the major problems with the Jumo 222 engine itself and various political machinations and swings in priority/development focus that doomed these aircraft.

Until 1944, the Jumo 222 was highly unreliable and especially troublesome when fitted to flying airframes. Ju-52s for the initial engine versions required engine swaps in as little as 20 hours, despite the engine passing its 100 hour bench test.

There were all sorts of problems with stress fracturing, lubrication, cooling and vibration that needed to be sorted.

The engine went through four major design iterations. Some major changes too: bore, piston stroke, timing, compression ratio, swept volume ect. All these development efforts only produced something satisfactorily reliable in the second half of 1944, provided it wasn't pushed too hard.

Supercharger development for the engine was slow as well, hampering the Bomber B program requirements in 1941-1942.

In addition, the shifting requirements of the Bomber B program aircraft meant that the engines not only had to be re-designed for reliability but also for more power, hampering things further.

Bomber B program aircraft.
Do-317. The Do-317 design was never considered that promising, dropped down the priority lists and showed little improvement over the Do-217 when it did fly
Ju-288. Doomed by the combination of the unreliable Jumo 222 and the aircraft's own complexity
Fw-191. Flight testing of first four aircraft showed the Fw-191 was so poor that the project was abandoned before the flight test program was even finished

Do-435 night fighter. Spin off of the Do-335 with lower development priority. It never flew, so I'm not sure how the lack of Jumo 222s "destroyed" the project
He-219 night fighter. Flew fine with DB 610s, if a little underpowered. Follow on 219B was to have 222s, but only a handful of aircraft were made, and the unreliability of the 222 reared its head again

Dr. Tank was designing a Fw-190 variant powered by the Jumo-222.

Ju-488 heavy bomber. A 1944 last-ditch strategic bomber program? This was destroyed by the

One of the He-177B prototypes was supposedly fitted with Jumo 222 engines.

There are probably more if you want to spend time searching.