The Horten IX and the Jumo 004

[Chris Wimmer]

Hello Everybody!

This thread is based on seiran01's fantastic building progress report of the upcoming Zoukei Mura Kit. It started as nothing but a review of the kits Jumo004 jet engine, but with more and more information coming in, I decided to give this interesting issue its own platform. The question is what changes had to be done to fit the Jumo engine to the airframe.

 

Let's start with the Jumo004 engine fitted to the Me262 on display at the Munich Museum. Note the huge generator mounted on the gearbox:

 

 

Obviously there wasn't enough space in the Horten's airframe:

 

 

According to Wouter's research work (thank you, Wouter!), the Horten brothers didn't know about the generator, because it wasn't mentioned in the technical drawings provided by Junkers. Finally they were allowed to fit the generator somewhere else in the airframe. The question is: Where? It had to be driven somehow, and also it needed to be cooled, so there must have been something like an airscoop, as seen here on the Me262:

 

 

Zoukei Mura tried to solve the problem by simply decreasing the generator's size. What did the Horten brothers do? I also wasn't sure about the shape of ZM's connector board:

 

 

The connector board on the Jumo 004:

 

 

...and Zoukei Mura's rendition:

 

 

The Jumo to me looks absolute fantastic, I only felt a bit disappointed about the connector board, which appears to be too low. However, today I found a picture on the web that changed my mind.

 

The starboard wing root:

 

 

A closeup of this pic shows an interesting detail: You clearly can spot the fuel filter, which actually should sit on the connector board:

 

 

The red outlined area is what you can see on the closeup picture:

 

 

Obviously the generator wasn't the only thing to cause fitting problems. Horten probably had to rework the connector board, so Zoukei Mura did.

 

 

Any more information highly appreciated! 

 

Chris

[Paul2660]

Thanks for posting. The engine is a kit in itself.

 

Paul

[seiran01]

This keeps getting better, i never thought I'd be so drawn to such detailed information about an engine but you and Wouter managed to pull me in.

 

I'll put money on the fact that ZM based their Jumo engines on the specific Jumos from NASM's 229 and am willing to bet that it's as accurate a representation of the Horten-modded Jumos as possible

[Ryan]

Great stuff, thanks for your efforts Chris!

 

Ryan

[Rick K]

thanks for posting this.

[Wurzacher]

Well observed! Great presentation!

[Wouter]

Hi,

 

great topic Chris. I found this picture in my reference, its apparently from the Ho229 V4 but gives a great overview of the Jumo engines and the accessories distribution. At least it's clear that what you pointed out that the fuel filter is relocated and that the generator is not where it should be. I have not yet spotted where they did put it though...

 

From 'Spirit of Thuringa', for illustrative purpose only

Edited September 11, 2014 by Wouter

[seiran01]

That photo is a gold mine! Thanks, Wouter!

[CATCplSlade]

Are those published photos or were you granted access to the magic realm of the renovation bay? I had to settle for fuzzy shots from the observation windows overlooking everything and the Horten was packed up along the far wall.

[Martinnfb]

It seems that the plane was still in the development and on the picture above is  visible  a loose hose/pipe and small frame. Would it be perhaps an attachment point for the generator and it'sfeed?.

Why to not keep it in place with fairing over it as it was done , on 109s, 190s and so on?

Just an idea..

Great research work Chris.

Cheers

M.

[Vandy 1 VX 4]

Hope this works for some ideas.  Also are there two small intakes on the center lower fuselage?

Fist photo is center Fuselage looking rear ward

https://www.google.com/search?hl=en&site=imghp&tbm=isch&source=hp&biw=1708&bih=761&q=horten+ho+229&oq=horten+&gs_l=img.1.1.0l10.2291.6441.0.8876.7.6.0.1.1.0.190.689.2j4.6.0....0...1ac.1.53.img..0.7.689.Q9IkUJ-59SY#hl=en&tbm=isch&q=horten+ho+229+landing+gear&facrc=_&imgdii=_&imgrc=jJiJCp-oKqCxmM%253A%3Be6l-eYrMDQCDHM%3Bhttp%253A%252F%252Fi73.photobucket.com%252Falbums%252Fi201%252FHenkG%252FHorton229V3landinggearport.jpg%3Bhttp%253A%252F%252Fwww.ww2aircraft.net%252Fforum%252Faircraft-requests%252Fhorton-brothers-flying-wings-3618.html%3B1024%3B573

 

http://www.warbirdsnews.com/wp-content/uploads/6658h.jpg

 

https://www.google.com/search?hl=en&site=imghp&tbm=isch&source=hp&biw=1708&bih=761&q=horten+ho+229&oq=horten+&gs_l=img.1.1.0l10.2291.6441.0.8876.7.6.0.1.1.0.190.689.2j4.6.0....0...1ac.1.53.img..0.7.689.Q9IkUJ-59SY#hl=en&tbm=isch&q=horten+ho+229+jumo+004+engine&spell=1&facrc=_&imgdii=_&imgrc=Ef5iSgZu8j2G5M%253A%3BqDCsjcn5OcT1gM%3Bhttps%253A%252F%252Fc1.staticflickr.com%252F1%252F192%252F493989907_13ad390c4e_z.jpg%253Fzz%253D1%3Bhttps%253A%252F%252Fwww.flickr.com%252Fphotos%252Fpublicresourceorg%252F493989907%252F%3B640%3B509

Edited September 12, 2014 by Vandy 1 VX 4

[Chris Wimmer]

All the Horten pics are published on the web, but all the Jumo pics are done by me. So here is another interesting shot, taken at the Science Museum London. Martin: The hoses and rods belong to the revolution controllers, which are both disconnected and removed. Thanks for sharing the links, Vandy!

 

And by the way: I swear that I haven't ever seen a Jumo 004 painted RLM02...  

 

 

Edited September 12, 2014 by Chris Wimmer

[Wurzacher]

 

 

And by the way: I swear that I haven't ever seen a Jumo 004 painted RLM02...  

 

Same here.

[mattlow]

Having looked at photos with the generator in place, it only appears to project an inch or so higher than the rest of the engine.

 

Surely this would/could have been incorporated within the cowl shape with a very subtle change in curvature - not even readily apparent to the eye in the images we have.

 

I can't imagine anywhere else on the engine where a drive could be taken for the generator. What isn't clear is where the air supply to cool it comes from and I don't honestly know.

 

Relocating the generator and designing a new drive for it seems like a  lot of faff for the sake of a small bulge on the cowl..?

 

Matt

[Chris Wimmer]

Matt, I think you're right. Modifying the cowling indeed requires the slightest expenditure and the pipe on the generator was removable. I've been told that the ZM-Fuselage shows a small airscoop located on the underside of each jumo. The jumo itself didn't have an air intake there, so maybe that's it !?!?

 

Chris