Ju-188 Worthwhile?

[davebender]

Junkers Aircraft of WWII

Ju-88A4. 2 x Jumo211 engines.
475 kph max speed.
4,550 kg payload.
2,900 km max range.

Ju-188E. 2 x BMW801 engines.
425 kph max speed.
5,160 kg payload.
2,800 km max range.

It appears to me the Ju-88 did not benefit by replacing the Jumo211 engines with larger BMW801 engines. So why build the Ju-188 at all? Just keep building Ju-88s powered by Jumo211 engines. Save the larger BMW801 radial engines for the Do-217 and / or Fw-190.

 

[Vincenzo]

davebender i think that data on speed of 188E is wrong

 

[davebender]

I noticed that too. However I hesitate to think Wikipedia is more accurate then the Junkers site.

Wikipedia data.

Ju-88A4. 2 x Jumo211 engines.
510 kph max speed. Without external bomb racks.
2,430 kph max range.

Ju-188E. 2 x BMW801 engines.
499 kph max speed.
2,190 km max range.

This makes the Ju-188 look even worse!

 

[Vincenzo]

we haven't no LW documents?

 

[Vincenzo]

i've that Ju 211J of A-4 give a take off power 1600 HP for 1' (at SL) the BMW 801G of 188 E give a take off power 1740 HP for 3' (at 1st gear, 0.9 klm), this unlucky all i've relative to performance


the Ju 211F/J pdf manual it's too low resolution, maybe also not a 1600, but the double 00 to end it's sure

reading on the net i can tell that is a 1400

i find a best resoluton version of ju 211 f/j manual so power of 211 J
1420 a 0 a takeoff power
1190 a 0 a combat&climb power
960 a 0 in fast cruising power
1260 a 1.5 km a combat&climb power (1st fth)
1080 a 2 km a max continous power
1180 a 4.9 km a combat&climb power (2nd fth)
1020 a 5.1 km a max continous power
1030 a 5.6 km a above FTH power (? i don't understand this setting)

power of BMW 801 G-2
1750 a 0.9 km a takeoff power (1st FTH)
1440 a 6 km a takeoff power (2nd FTH)
1540 a 1.1 km a combat&climb power (1st FTH)
1320 a 5.6 km a combat&climb power (2nd FTH)
1385 a 1.6 km a max continous power (1st FTH)
1180 a 5.8 km a max continous power (2nd FTh)
1070 a 2.2 km a cruising power (1st FTH)
990 a 5.7 km a cruising power (2nd FTH)
980 a 2.2 km a economical cruise power (1st FTH)
905 a 5.7 km a economical cruise power (2nd FTH)

 

[Colin1]

Junkers 88A-4 :Name: Junkers 188E-1
2 x Jumo 211J 12-cyl inv V @ 1,340hp each owerplant: 2 x BMW 801G-2 18-cyl 2 row radial @ 1,700hp each
17,637lbs (8,000Kgs) :Weight (empty): 21,825lbs (9,900Kgs)
30,865lbs (14,000Kgs) :Weight (loaded): 31,730lbs (15,300Kgs)
269mph (433kph) @ not given :Max speed: 315mph (494kph) @ 19,685ft (6,000m)
1,312ft/min (400m/min) :Climb rate: not given
26,900ft (8,200m) :Ceiling: 31,170ft (9,500m)
1,112miles (1,790kms) :Range: 1,550miles (2,480kms)
2 x MG81; twin MG81; 2 x MG81 (rear); 2 x MG81 (gondola) :Armament: 2 x MG151/20; 2 x MG131; 1 x MG81
6,614lbs (3,000kgs) :Ordnance payload: 6,614lbs (3,000kgs) bombs

The Ju188 wasn't designed with the BMW 801 in mind, they were designed with the Jumo 213, the Jumo unit simply wasn't ready on schedule; 213-equipped versions of the 188 were capable of 435mph (696kph).

 

[davebender]

It's my understanding the Jumo211F engine entered production during 1941 and produced 1,350 hp. It was quite reliable.

During 1941 the BMW801C produced 1,540 hp. It was still an unreliable engine at this point. The BMW801 was much larger and heavier then the Jumo211 engine, requiring an increase in aircraft weight.

I'm starting to think the Fw-190 fighter would have been further ahead powered by the Jumo211F engine. Was the Jumo211 series capable of further development, as the DB601/DB605 was?

 

[Vincenzo]

colin idk your source but 88 A-4 go until 425 km/h in cruise

 

[Vincenzo]

jumo 211J was used later on 88 A-4, the power data on BMW 801 G came to 188 E 1 manual

p.s. A-4 manual, of juli '41, talking only of 211 J engine

 

[machine shop tom]

The Jumo 211 development was ended in favor of developing the Jumo 213, which DID end up in the FW-190D. The 211 was limited in development capability compared to the more modern 213 series.

tom

 

[davebender]

Jumo 211 development was ended in favor of developing the Jumo 213

The 1,350 hp Jumo 211F entered mass production during 1941. The 1,750 hp Jumo 213 entered mass production during 1944.

What happened to the Jumo 211 engine during 1942 and 1943? Did they make an effort to further increase HP as Daimler-Benz did with the DB605 engine?

 

[Shortround6]

What happened to the Jumo 211 engine during 1942 and 1943? Did they make an effort to further increase HP as Daimler-Benz did with the DB605 engine?

There were Jumo 211 N and P versions which ran another 100rpm and used slightly higher manifold pressure for take-off ratings up to 1500HP. The "J" version with intercooler was good for anywhere from 50-80HP over the "F" depending on conditions (altitude,rpm, climbing or cruise)

 

[davebender]

The "J" version with intercooler was good for anywhere from 50-80HP over the "F"

So Junkers made a few small improvements to the Jumo 211F but essentially decided 1,350 to 1,400 reliable hp was good enough. Better to concentrate on low cost mass production while waiting for the next generation Jumo 213 engine.

A perfectly reasonable decision during wartime. The 1,350 hp Jumo 211F engine compares nicely with the 1,200 hp R1820-97 engine which the U.S. standardized on for the B-17, B-24, DC-3, SBD dive bomber and F4F fighter.


Back to the main topic....
The Jumo 211F engine appears to have been a good match for the Ju-88A light bomber. I don't think the early model BMW801 engines were an overall improvement.

Jumo 213 engines were an improvement but now we're talking about a late war aircraft. By then most Ju-88s and Ju-188s were being produced as night fighters and recon aircraft.

 

[riacrato]

I'm starting to think the Fw-190 fighter would have been further ahead powered by the Jumo211F engine. Was the Jumo211 series capable of further development, as the DB601/DB605 was?

The Jumo 211 was reserved for the bombers, the 801 was otherwise unused. Let's not forget we can't just put every engine into a fighter, there are other demands to fill.

Also, is seem to recall the later Czech, Jumo 211 powered variants of the 109 were found to be crap. Probably had to do with the gearbox, I don't know. But I'm sure if the Jumo 211 powered Bf 109 were disliked by the pilots, similar could apply to the 190. So there would've been need for development/redesign.

 

[davebender]

The BMW801 was unused during the first half of WWII because it was not in mass production.

U.S. Strategic Bombing Survey Aircraft Division Industry Report
BMW 801 engine production did not achieve 200 engines per month until January 1942.

 

[riacrato]

There was also no project intending to use it because it or its predecessor the 139. As opposed to for example several projects already waiting for the Jumo 222 which never came at all.

In 1941, BMW still had the capacity, Junkers was already overstretched. Likely not much less so than DB.

 

[davebender]

Which makes me think it was a mistake to spend all those years perfecting the BMW801. They could have been producing additional DB601 engines during the early war period. Then switched to DB603 production during 1942, for installation in the Fw-190. That would give the Fw-190 designer his preferred engine.

 

[riacrato]

I only ever read Tank preferred the DB 603 over the Jumo 213, as a high altitude fighter engine. I don't know if he preferred it per se.

The Fw 190 entered service in 1941. Even though the BMW 801 C is not reliable it's still a considerable period of introduction and familiarization you would deny to the pilots until the engine/airframe is improved and reliable enough in spring 1942. And in 1942 the DB 603 was not exactly reliable enough either.

 

[johnbr]

I have Readied that 188 was to get the bmw 802.

 

[davebender]

How is that possible? The BMW 802 engine wasn't even a blip on the horizon when Ju-188 aircraft development began. Not to mention making such a massive engine fit on a wing designed for the relatively small Jumo 211 engine.

1940. Ju-188 prototype first flight.
1943. BMW802 engine prototype first run.

The BMW 802 engine might have been a good match for the larger Ju-288 bomber, as an alternative to the Jumo 222 engine.