Jumo 222: what's the truth?

Discussion in 'Aviation' started by wiking85, Nov 29, 2013.

  1. wiking85

    wiking85 Well-Known Member

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    I know this is more a thread for the engine subforum, but I've already broached the topic there in this thread without much in the way of answers:
    http://www.ww2aircraft.net/forum/engines/jumo-213-what-took-so-long-39029.html

    Anyway my question is why was the Jumo 222 really not put into production? From what I've read recently via Lutz Budrass it seems that it was a combination of being developed to death (by constantly upping the HP requirements and displacement just as the previous requirement was being met) and being placed on low priority to undermine Erhard Milch's rival, Dr. Heinrich Koppenberg, who was running the Ju 288/Jumo 222 program (he also separated the program to kill it too). Budrass pretty much states that this rivalry killed the engine, rather than technical issues being the real cause of it never entering production status.

    It also seems that in April 1941 the Jumo 222 in its original design configuration (2000 hp) achieved 100 hours on a bench test, which is a strong indication that it is closing in on being production ready, though there were still some issues with corrosion and piston seizure that set in at about 50 hours (which in 1941 was better than the BMW 801 or DB 603). Eventually this original 2000hp configuration and displacement was the version, the Jumo 222E/F that was the one that actually got near production status in 1943 before Allied bombing killed it for good (though work continued on refining it until 1945). However in 1941 the requirement was upped to 2500hp in response to the Ju 288 airframe gaining weight during the development process, which required an increase in power from its engines to keep up performance. This of course set back the process and prevented the engine from getting ready until 1943 at which time the requirement was again bumped up to 3000hp, setting development back again.

    So based on all of this it seems that had the original displacement and HP output been kept from 1941 on the engine would have been ready some time in 1942 for serial production, though perhaps not at the 100 hour between overhaul mark (which didn't keep the BMW 801 or DB 603 from production historically). Obviously it would be weaker than needed for the Bomber B program, which IMHO should have been killed at the point its weight jumped up too far for the engine, but it would have had plenty of other uses in the He 177B, Do-217, Ju 188, and even a FW190 version (or Ta-152 which tested with the Jumo 222 historically). The fuel consumption would have been significantly better, as the smaller cylinders were more efficient than say the DB 603 or BMW 801, and the weight and dimensions wouldn't have been that much bigger than the DB 603.

    Am I missing something here or was the Jumo 222 killed by administrative action and development rather than technical issues?

    As a side subject, what would its effect have been had it entered production in March 1942 with 70 hours between overhauls and no greater requirement for strategic materials than say the DB 603 of Jumo 213? Would it have meant an earlier He 177B powered by these engines, a Do-217 not underpowered, a Me 410 with Mosquito-level speed, a FW-190/Ta-152 with altitude performance challenging the P-51, a Ju 188 with better performance than the Ju88, and a series of night fighters/intruders that actually lived up to spec (like the He-219, Ju 88G, and Ju88S)?
    What becomes of the Ostmark production facility if it were actually able to start operations with its original tooling, rather than being partly retooled for the DB603 and not really ever being operational?
     
  2. Shortround6

    Shortround6 Well-Known Member

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    Basically the thing was a turkey. Color it which ever way you chose but most sources will agree that around 270-280 engines (of various versions) were built. That is one HE** of lot of test engines. Please remember that R-R built 301 Peregrines total and kept two squadrons of twin engine fighters in combat service for around two years. The 270-280 Jumo 222s powered about 1/2 dozen air frames ( and briefly). Did somebody order a "trial" batch of a few hundred engines before they were ready? Even if we "assume" 70-80 "test engines" (P&W built about 50 R-4360 28 cylinder 4 row radial test engines, including flight test) that leaves us with about 200 Jumo 222 "semi" production engines that apparently were not deemed airworthy. Considering the number of weapons systems that the Germans bodged together out of mis-matched parts you would think that 200 or so air worthy 2000hp engines would have found SOME use.

    As for "The fuel consumption would have been significantly better, as the smaller cylinders were more efficient than say the DB 603 or BMW 801" there is efficiency and there is efficiency, Trying to use a bunch of small cylinders can make for better volumetric efficiency but that may not mean better fuel efficiency.
    A Jumo 222A (46.5 liters) had 1.3734 sq meters of scrubbed cylinder wall.
    A BMW 801 had 1.0698 sq meters of scrubbed cylinder wall.
    A DB 603 had 1.0987 sq meters of scrubbed cylinder wall.

    Most people figure that about 80% of the internal friction of an engine comes from the pistons/piston rings scrubbing the cylinder walls the Jumo 222 has about 25% more piston/cylinder friction than a DB 603 at the same rpm. Since friction goes up with the square of the speed and the Jumo 222 is going to faster in most cases it is burning more fuel to over come internal friction. Now perhaps the Jumo can make the same power (being more efficient?) as the DB 603 while cruising at a lower rpm than the DB 603 and get back some of the fuel economy?
     
  3. wiking85

    wiking85 Well-Known Member

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    The argument of the number of engines produced is somewhat a matter of details, as there were radically different versions due to the increase in displacement and various reengineering schemes that altered the engine so much that it needed a new set of test engines. There were four displacement changes from 1941-44, which resulted in cylinder changes each time and of course multiple different supercharger and later turbocharger designs. Cooling systems were rerouted with these changes too, which pretty much resulted in different test models all while having its priority constantly changed and switched from different proposed aircraft (it was tested with at least 7 different designs that I'm aware of). All this makes total sense why it would have so many test engines.
     
  4. wuzak

    wuzak Well-Known Member

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    The DB 604 was better....
     
  5. Shortround6

    Shortround6 Well-Known Member

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    Not really, see:

    The Hugo Junkers Homepage

    Granted there may be some problems with translation but twice production is stated to be stopped? If the engine wasn't ready to go why start?

    Please note that there are some discrepancies between the chart of engines on that page ( and some discrepancies in the chart itself) and a chart in an article in the "Torque Meter" magazine by Kimble McCutcheon on the bore and stroke of some of the models.
    Granted there were a lot of different models and bore and strokes but why you would need 30-40 new test engines for a 5mm bore job is beyond me. Or 30-40 new engines with the same bore and stroke but a new supercharger set up?

    Aircraft it actually flew in seem to be one (or more?) JU 52 test bed aircraft, two (or 5-6?) Ju 288 prototypes 9 different series) , one Fw 191 prototype. A few He 219 Prototypes. And a number of these prototypes were held up by the lack of "fight cleared" engines. Something isn't adding up.

    I was also in error on the R-4360 engine, it had 15,000 hours of ground running with 23 engines, not 50, before being deemed "reliable" with no definition of 'reliable' being given. Some service users of the R-4360 may beg to differ but at least it powered service aircraft.

    Of interest may be this history of the P&W R-4360 engine.

    http://www.enginehistory.org/P&W/R-4360/R-4360History.pdf

    of note is that the first "lash up" engine was running about 5 months from the start of work and the engine was flying in a test bed aircraft in 18 months from start of work. Also note the testing done with single row and single cylinder test rigs.

    Please note that the R-4360 used a variety of supercharger set ups.

    Somehow "needing" 270-280 "test" Jumo 222s doesn't seem quite right :)
     
  6. wiking85

    wiking85 Well-Known Member

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    It also flew on a He 177/277 prototype and there was a TA-152 prototype as well. IIRC there was also a Do-317 prototype the flew with it.
    As to the website...what's its source for information? There is a lot of unsourced internet information out there.
     
  7. Shortround6

    Shortround6 Well-Known Member

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    That is the problem with much of the material about the Jumo 222. Some of the information on the website may have been taken from Putnam's " Junkers Aircraft Engines 1913=1945" By Antony L Kay or perhaps they used some of the same sources. In any case the charts listing the different models on some websites are wrong. (just use the listed bore and strokes to figure out the displacement and see the errors, one model engine just needs 12 more cylinders {total 36} to reach the listed displacement with the listed bore and stroke)

    As for the 177/277 prototype or the TA-152 prototype do you have a V number? I have no doubt that plans were made, I wouldn't put money on metal not being cut but actually flown?

    Maybe my books are old and out of date but this seems like a phantom engine, lots of models and differnet sources saying confusing things ( and maybe the 289 number is a mistake and just copied form one book/site to another) but even the planes that flew with it are noted as not having flown long or without constant trouble. If the 289 number is right (or anything close to it) the program was a colossal waste of effort ( a few Allied programs got shut down before going quite as far and justly so and a few more should have been.)
     
  8. wuzak

    wuzak Well-Known Member

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    I am reading about the He 177 now, and thus far there had been no mention of the Jumo 222. The He 274 was to be powered, from a quick glance, by 4 x DB 603 or 4 x BMW 801.

    The Ta 152 with Jumo 222 was a proposal, rather than a flying prototype.


    That may be the case.

    The early Ju 288s definitely had them.

    But if the Jumo 222 was indeed reliable and production ready at 2000hp, then why weren't they suggested for the Me 264? The Me 264 was designed for Db 603s (1750hp), ended up with Jumo 211s (~1200-1300hp?) and finally BWM 801s (1750hp). If a 2000hp engine was ready and waiting I'm sure Messerschmitt would have jumped at the chance.

    (Curiously they didn't have DB 606/610s as an option either.)
     
  9. wiking85

    wiking85 Well-Known Member

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    #9 wiking85, Nov 30, 2013
    Last edited: Nov 30, 2013
    http://www.ww2aircraft.net/forum/engines/engine-quastion-about-he-177-a-11699-3.html
    http://www.ww2aircraft.net/forum/aviation/powerplants-fw-190-ta-152-a-35474.html
    From GregP:
    As to the reason it wasn't reliable at 2000hp was that that version was cancelled in 1941 and upped to 2500hp before it was ready; then when it was reapproached at 2000hp in 1943 the Dessau plant was wrecked by allied bombing, which made production of the engine impossible, so the Me 264 didn't have access to the Jumo 222E/F, which, from what I've gathered, nearly entered production but for the bombing.
    My point was that it could have been ready in 1942 if the order for a higher hp version didn't come down in 1941, which set the project back to getting the engine up to the new standard, in effect killing the chance to get the 2000hp version ready in a timely fashion before strategic challenges set in. The other issue is that by 1942-43 Milch had decoupled the engine from the Ju288 project, which meant it was relegated to secondary (or even tertiary) status in terms of funding and engineering resources.

    From what I've gathered this book has the most complete info about the engine:
    http://www.amazon.com/Flugmotoren-S...iebe-Gemeinschaftsentwicklungen/dp/3763761071
    I don't have access to it, but I might be able to get it via interlibrary loan and can translate it.
     
  10. stona

    stona Well-Known Member

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    #10 stona, Nov 30, 2013
    Last edited: Nov 30, 2013
    That needs some clarification.

    V101 was PROBABLY the burnt out aircraft found at Cheb in 1945. It had first flown with four DB 603 A engines way back in December 1943. It was an obvious choice to convert one four engine version (DB 603) to another (Jumo 222), probably in connection with the He 277 program. As far as I know nobody knows whether V101 ever flew in this configuration.

    I can find no evidence that the Jumo 222 was ever considered for the He 177. The B-0 was to have four BMW 801 engines. Drawings of the various versions of the B-5 all have four DB 610 engines. A specification for the B-6 calls for four BMW 801 engines with mention of a variant with four Jumo 213 Es. Finally the B-7 proposal was to have had four DB 603s. Since none of these (B-0,B-5,B-6,B-7) were ever built it's a moot point, but at no time is the Jumo 222 mentioned.

    The He 277 is also irrelevant. It barely got off the drawing board and I don't believe that a single prototype was ever completed. Some sources suggest that some examples were built, but were destroyed by allied bombing, but the hard evidence for this is, politely, elusive.

    Cheers

    Steve
     
  11. davebender

    davebender Well-Known Member

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    Prototype first run for both engines was during 1939. If fully funded to production status per original 2,000hp specification I suspect both could have been in mass production during 1942.

    Daimler-Benz was working on a multitude of engine projects during WWII for Schnell boats, submarines, tanks etc. in addition to DB601/DB605 aircraft engine. IMO it makes sense to give 24 cylinder aircraft engine project to Junkers rather then burden Daimler-Benz with another major project.
     
  12. DonL

    DonL Banned

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    #12 DonL, Nov 30, 2013
    Last edited: Nov 30, 2013

    I have very very serious doubts about such a claim.
    No 604X was ever in the air and it was also a major development project of DB since 1938 for the Bomber B.
    To all german sources the DB 604X was far away from the development of the Jumo 222,
     
  13. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Hi, DonL, maybe you want to say that Jumo 222 was far ahead from the development of the DB-604, since no 604 ever got in the air?
     
  14. DonL

    DonL Banned

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    Oh sorry yes, wrong language
     
  15. Rick65

    Rick65 Member

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    The more I read about the German programs for 2000hp+ engines the more I realise what an achievement the Napier Sabre was, with flight in the prototype Typhoon in early 1940 and service introduction in mid 1941. It initially had reliability problems, and service models didn't offer power at height but it was in production and being used in operations when the German (and US ) equivalents were not.
     
  16. wiking85

    wiking85 Well-Known Member

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    It didn't hurt that the Sabre started development two years before the equivalent German or US designs.
     
  17. wuzak

    wuzak Well-Known Member

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    I didn't say that the DB 604 was more advanced, I said iit was better than the Jumo 222.

    Certainly at the time of cancellation the DB 604 would have been at least equal in power. Take-off power was listed at 2660hp and mximum 2410hp @ 20,600ft (6279m):

    GED0109

    Compared with 2500hp at take-off and 2490hp @ 16,400ft (A-2/B-2) or 2200hp @ 16,400ft (A-1/B-1).

    GED0116

    The 3000hp version seems to require MW50 for take-off and GM-1 for altitude performance.

    Max Cruise performance is slightly in favour of the Jumo 222 at sea level (1900hp vs 1830hp) but in favour of the DB 604 at altitude (1860hp @ 20,000ft vs 1750hp @ 16,400ft).

    Physically they are the same capacity (depending on versions), are about the same weight (2400-2500lb/1089-1134kg), but I don't have any exterior dimensions for teh DB 604.

    DB604

    http://enginehistory.org/German/Jumo222/Jumo222Fig04.jpg

    Plus, I think the DB 604 looks neater.
     
  18. wiking85

    wiking85 Well-Known Member

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    I've read that the Jumo was more fuel efficient and therefore preferred, as it would give the Ju 288 the range it needed to meet spec.
     
  19. Shortround6

    Shortround6 Well-Known Member

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    This is were things get murky. We have documents that don't make sense. Please figure the capacity of the DB 604 based on the numbers given in GEDO109. If I am doing the math right the 46.5 liter capacity is correct for an engine using a 135mm bore and a 135 mm stoke. Using a 140mm bore should give you a Displacement of 49.85 or 49.88 liters. and a 135 bore and 140mm stroke DOES NOT give 50 liters. It gives 48.07 liters.

    As for fuel economy? both are 24 cylinder engines using just about the same sized (if not THE same sized cylinders) at the same max rpm ( and cruising rpm?) and depending on exact engine measured, the same compression ratio? Granted they seem to vary a bit form source to source. But one torn down Jumo 22 had a 6.75 compression ratio and one description of the DB 604 says 7:00 to 1 compression ratio?
    We are left with differences in piston/piston ring fit, bearing drag, exact power used to drive supercharger, ignition timing ( and they are going to be close also) pumping losses, etc to try to explain which engine was more "economical" and since the amount of actual flight testing ranges from Nil (DB 604) to not much ( Jumo 222) we are left with manufacturer's "estimates" (sales pitches). Maybe the Jumo was more economical but there is no "feature" that points to it. (Allison used a 6.65 compression ratio compared to the Merlins 6.00, 10% greater which helped fuel economy. These engines show a 3.7% difference in compression and in the DB 604's favor?
    Both engines were fuel injected.

    We are firmly in the land of "What if" just out side the city of "Maybe" next to the river "It might have" and in the shadow of the mountain peak "not sure" when dealing with these two engines :)

    even reports of torn down Jumo 222 engines in allied hands don't agree with each other or with German sources (150mm bore on a Jumo 222 ??) Could be a simply typo ( I make more than my fair share :)
     
  20. davebender

    davebender Well-Known Member

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    The most important achievement was keeping the engine on track for mass production @ the original 2,000hp specification. Whoever was in charge of British aircraft engine production was clearly more competent then his German counterpart.
     
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