Jumo 213, what took so long?

[wiking85]

The original run for this engine was in 1940, but it wasn't declared production ready until 1943...what took so long for it to become production ready?
https://en.wikipedia.org/wiki/Junkers_Jumo_213

The 213A first ran in 1940, but experienced lengthy delays before finally being declared "production quality" in 1943. Production was extremely slow to ramp up, in order to avoid delays in the existing Jumo 211 production.

I've read recently that there were issues with the radiators, but don't know anything beyond that. Can anyone shed some light on this?

 

[davebender]

Jumo 211 engine program was a huge cash cow for Junkers.

RLM cancelled DB603 engine program during 1937 to 1940. Even after program was resumed (following land speed record attempt) RLM appears to have dragged their feet on development and mass production.

Given these conditions Junkers had little financial incentive to rush the Jumo 213 program. If DB603 program had been fully supported from 1936 onward then Junkers probably would have put more effort into their competing Jumo 213 program.

 

[Denniss]

A Jumo 213 prototype may have run in 1940 (although I very much doubt this) but not in the form it appeared in 43/44. The 213 was based on later model 211 with very much increased rpm thus the real development was proably not started before 1941 (when the 211J slowly started to appear).

 

[rinkol]

I have a recollection that the firing order had to be changed to fix vibration issues.

 

[stano666]

Hitler tought he'd won the war in may 1940, lots of things where put on low speed becouse of that, a grave mistake.
Sure there's much, much more to it, yet as a rule of thumb (i hope i use this figure of speech correctly) this thinking didn't do Germany any good, and i'm sure the 213, 603, and other projects sufered from it.

 

[DonL]

Most of Junkers engine development department from 1937 to 1941 was working on the Jumo 211 and Jumo 222
The big Jumo 222 for the Bomber B has priority A wide away from the Jumo 213 which was a very very low priority engine for Junkers from 1937- first half 1941.
Not until the realy big problems of the Jumo 222 crankshaft and the stopping of the whole project through the RLM at the end of 1941, Junkers shift major development powers to the Jumo 213.

Here you can see that the Jumo 222 costs 3-4 years development time of the Jumo 213.

 

[davebender]

That sounds logical.

Late 1930s Junkers was probably led to believe the Luftwaffe would skip over next generation V12 and go to V24 engine plus the radial BMW801. Cancellation of DB603 funding certainly pointed in that direction.

 

[wiking85]

Most of Junkers engine development department from 1937 to 1941 was working on the Jumo 211 and Jumo 222
The big Jumo 222 for the Bomber B has priority A wide away from the Jumo 213 which was a very very low priority engine for Junkers from 1937- first half 1941.
Not until the realy big problems of the Jumo 222 crankshaft and the stopping of the whole project through the RLM at the end of 1941, Junkers shift major development powers to the Jumo 213.

Here you can see that the Jumo 222 costs 3-4 years development time of the Jumo 213.

Is it true that the Jumo 222 program did bear fruit in 1943?
https://en.wikipedia.org/wiki/Junkers_Jumo_222

Junkers still did not give up. Using the original 46.4 litre displacement A/B design, they added a new two-stage supercharger including a trio of aftercoolers, one per pair of neighboring cylinder banks for high-altitude use, producing the 222E and F-series. Although sea-level performance was unchanged, the engine was able to produce 1,439 kW (1,930 hp) at 9,000 m (29,530 ft). By this point it appeared that the problems were finally being worked out, but bombing of the Junkers Motorenwerke's headquarters factories in Dessau made production almost impossible. A final attempt for even higher altitude performance resulted in the turbocharged 222G and H, built only to the extent of a few testbed prototypes.

 

[davebender]

Original 1937 specification for Jumo 222 engine required 2,000hp. Jumo 222 engine passed 100 hour endurance test @ 2,000hp during April 1941.

Then the political games began. RLM kept raising the bar for Jumo 222 performance in an apparent effort to keep the engine from entering mass production. Difficult to understand how or why that happened when the engine was badly needed for aircraft such as Do-217 bomber and He-219 night fighter. Even with "only" 2,000hp it was far superior to other engines powering those aircraft.

However Jumo 222 development and non mass production is a can of worms that belongs in a separate discussion.

 

[wiking85]

Original 1937 specification for Jumo 222 engine required 2,000hp. Jumo 222 engine passed 100 hour endurance test @ 2,000hp during April 1941.

Then the political games began. RLM kept raising the bar for Jumo 222 performance in an apparent effort to keep the engine from entering mass production. Difficult to understand how or why that happened when the engine was badly needed for aircraft such as Do-217 bomber and He-219 night fighter. Even with "only" 2,000hp it was far superior to other engines powering those aircraft.

However Jumo 222 development and non mass production is a can of worms that belongs in a separate discussion.

What's your source on it running at 2000hp in 1941???

 

[silence]

I have a recollection that the firing order had to be changed to fix vibration issues.

As I recall you are correct. It was an easy fix, but since the engine was not designed for the revised firing sequence it lost a little power.

Now where did I read that?...

 

[davebender]

https://groups.google.com/forum/#!msg/rec.aviation.military/9O6HdlO8waM/x01xZKPQxFcJ

Based on 1936 Jumo studies for a 1800 PS engine, in 1937 the RLM ordered a 1900 PS engine (24 cylinders, liquid-cooled) for left- and right-handed operation. Ferdinand Brandner, who was new at Junkers, was to develop this engine, which he projected as a 2000 PS, 6 rows of 4 cylinders design. It ran first in 1939 and in 1940 developed 2000 PS on the dynamometer and was flown as middle engine in a Ju 52. In 1941, it completed a 100 hour test on the dynamometer

The next generation of Jumo 222 engines had an increased bore for increased power. In December 1942 a 100 hour test at 2500 PS was completed successfully

So there you have it. 2,000PS during 1941. 2,500PS during December 1942. And RLM still didn't want the Jumo 222 engine to enter mass production. Strange behavior for a nation in a desperate struggle for survival.

 

[wiking85]

https://groups.google.com/forum/#!msg/rec.aviation.military/9O6HdlO8waM/x01xZKPQxFcJ


So there you have it. 2,000PS during 1941. 2,500PS during December 1942. And RLM still didn't want the Jumo 222 engine to enter mass production. Strange behavior for a nation in a desperate struggle for survival.

From what book was this? Also just because a prototype was able to run at that doesn't mean a production version would...I'm somewhat skeptical that it was ready and not put into production; there had to be another issue that wasn't meshing yet.

Edit:
http://books.google.com.au/books?id...&ved=0CC8Q6AEwAA#v=onepage&q=jumo 222&f=false
This paints another picture

 

[Shortround6]

They built about 270-280 Jumo 222s of various types, not a mistyping, about 270-280 complete engines, they powered fewer than a dozen air-frames. Given the German propensity for cobbling together odd bits and pieces of equipment and using them in service this seems like a glaring waste of an existing resource IF the engines actually worked.

Mr. Bender continues to ignore that while some engines passed a type test and went on with little trouble into production many other engines did not. Passing a type test was a significant milestone but in all too many cases was no guarantee that an engine was ready for service use just because it passed a type test. This happened with both allied and axis engines.

The German air Ministry also changed the goals for power required because of a constant weight escalation in the prototypes intended to use the Jumo 222 which meant they gained thousands of pounds of weight from initial proposal to prototype in near service condition which means had they been but into production with the 2000hp Jumo 222 they would have been under powered and fallen short (in some cases way short) of projected/desired performance. As an example the Ju 288 design grew from a 51'6" wing as proposed to a 60' wing as accepted by the RLM for construction and then through 66'3" wings to 72' 2" to 74'4" wing by the 6th prototype. Normal take-off and max loaded weight had escalated to 39,022lb and 41,000lb respectively from the estimated 33,850lb and 38,900lb of the 60ft wing span version. And that is before the change to a 4 man cockpit instead of 3 man.
The Fw 191 prototype was test flown at weights around 45,000lbs with BMW 801 engines because the Jumo 222s weren't ready. It wasn't going to get smaller or lighter when fitted with Jumo 222 engines.

 

[DonL]

From various sources came the claim, that the problem solved Jumo 222 crankshaft was in need for too much copper to put it in a serial production, without too much problems for other munitions.

 

[wiking85]

From various sources came the claim, that the problem solved Jumo 222 crankshaft was in need for too much copper to put it in a serial production, without too much problems for other munitions.

Copper? I read it was tin and that was only because they kept bumping up the HP demands before they could solve the previous demand. So if the 2000hp requirement was kept it could have been ready in 1942 for serial production at that level, but was ordered to achieve 2500hp in 1941, so instead spent the time until 1943 working on a new displacement at which time it was upped to 3000hp and set the development team back to square one.