DB-610: build your Luftwaffe

[tomo pauk]

An invitation for a discussion about the coupled DB engine, but a late war Luftwaffe using it in combat planes would be nice to discuss too.

 

[davebender]

I prefer the 4 engine He-177B. However after Heinkel fixed the cowling problems the He-177A5 was a good bomber.

 

[tomo pauk]

All fine and dandy, however it does not have any bearing towards the thread

 

[tyrodtom]

It's just a case of the hottest part of a engine, where the shared exhaust manifold of the 2 inverted V engines, just about coincided with the low point in the engine nacelle, which would be the point where any leakage from the engines would end up. So the engine evidently needed extraordinary leakage control, and/or better cooling in the central bottom of the engine nacelle. Good idea, coupled engines, but poor execution with the details.

Couple that with the He177, bury that engine deep in the wing, attach it to the mainspar, with (what appears to be) no firewall, or the mainspar IS the firewall. With the oil tanks directly behind that mainspar, with fuel tanks on each side of those oil tanks. So if the engine does catch fire, you've got very little time before either the mainspar fails, or the oil/ fuel tanks ignite.

 

[tomo pauk]

Wasn't the Db-606 plagued with those issues, but the 610 was trouble-free?

 

[Juha]

Wasn't the Db-606 plagued with those issues, but the 610 was trouble-free?

At least early 610s were still far from trouble-free.

Juha

 

[tomo pauk]

As I've said, the thread is more of an invitation for a discussion about Db-610 - I'd like to learn more about it

 

[tyrodtom]

My face is red, I got the DB-606 and Db-610 confused.
The 610 improved on a lot of the 606's problem areas, more ventilation in the nacelle, better exhaust manifold package. Not a lot of info out there.

But i'm sure someone will speak up for it.

 

[davebender]

Wikipedia to the rescue.
Heinkel He 177 - Wikipedia, the free encyclopedia

Starting with the He 177 A-3/R2, a modified engine nacelle with a new engine, the Daimler-Benz DB 610 which consisted of a pair of Daimler-Benz DB 605's, was used to eliminate the tendency for engine fires.[19] With the introduction of the DB 610 came several improvements including the relocation of the engine oil tank, the lengthening of the engine mountings by 20 cm (8 in), the complete redesign of the exhaust system which also facilitated the installation of exhaust dampers for night missions, and the setting of a power limitation on the engines which resulted in greater reliability. These modifications, supposedly numbering 56 of both major and minor varieties, were successful as far as eliminating engine fires were concerned, but other minor problems with the transfer gearbox between the two component engines of each "power system" and their shared propeller remained.

Production.
130 x He-177A1. Jan 1942 to Jan 1943.
15 x He-177R1. Nov to Dec 1942.
.....135 production aircraft before He-177A engine problems were fixed.
.....I still prefer the He-177B but I don't think one year is bad at all for fixing technical glitches in a newly introduced heavy bomber.

155 x He-177AR2 and later variants. Jan 1943 to June 1944.
826 x He-177A5. Dec 1943 to Aug 1944.

 

[wuzak]

The Me261 seemed to have less difficulty with its DB606s (V1 V2) and DB610s (V3) than the He177.

Also, what if each engine half were to drive its own prop, ala Fairey P.24? Would that have been a solution, or woud that have introduced new problems (pitch control for co-axial props)?

 

[Denniss]

German wiki has an exact listing of how many He 177 were built.
Heinkel He 177
"A-3 neuer Bauzustand" would be those with fixed engine nacelles, those with "Kehl" were prepared to use glide bombs

 

[tomo pauk]

A part of 'my' Luftwaffe would be a pusher, layout as of Saab 21, or maybe a full-length hull, akin to the various Dornier pusher projects (allows for more room, but it's harder to make space for prop clearance, unless we go for a counter-rotating prop). A NF two-seater, with crew compartment akin to Ki-45 (enabling Schraege musik; no tail gun here), front-firing cannons under the crew compartment. Another version of the same would be an attack aircraft, single seater, with dive brakes, 2 cannons 30-37mm.

 

[krieghund]

The Me-261 nor the He119 encounter problems with either the DB606 or DB610. It was the installation into the airframe that made the difference ( or in this case, the He177 problems).

As a rule coupled engines are too heavy for small (fighter) applications and would take up an excessive amount of the empty weight percentage of anything smaller than a P-75, Do335 or Ki-64 sized fighter. Of course the P-75 hosted the coupled V-1710(V-3420).

It might be an interesting study to look at all the different "coupled" and the aircraft they were installed in, but that is off thread.

Anyway, I kind of like the looks of the J7Wx with a DB610 in it. I would have to scale it up a bit though or maybe not.

 

[tomo pauk]

What was the weight of the DB-610, either dry, or as a complete installation?

 

[Shortround6]

1946 Janes gives a weight for the 606A (right hand rotation) as 3333lbs with starter, and the 606B (left hand rotation) is 3443lbs, with starter.

The 610A is given as 3388lbs and the 610B as 3476lbs (right and left rotation) condition not given.

 

[tomo pauk]

That should be dry weight; DB-605AM is listed as being 1667 lbs dry (Wikipedia. I know...). So we should look at 4500+ lbs installed - a tad heavier than P-47 powerplant? It should direct towards a size of a sinle-engined plane to carry it, circa 350 sq ft wing etc?

 

[SpicyJuan11]

How did the coupled engines(DB 606,610,613)compare to other 'single' high powered engines such as the Jumo 222 C/D, BMW 802, and even the BMW 803? Were the coupled engines not really worth their weight compared to the 'singles'? Also, assuming the He 177 didn't encounter it's horrendous engine troubles, would German engineers be more comfortable in using coupled engines in their bombers? Many thanks.

 

[kool kitty89]

There's also the pre-war 2000 hp class 18 cylinder Bramo 329 that might have developed into something compelling in the vein of what the 606 and Jumo 222 were targeting initially had BMW not canceled development after their merger with Bramo. (admittedly, an earlier, more conservative 18 cylinder BMW 801 derivative might have made as much or more sense given the common bore/stroke and potential common tooling with the 801 for easier manufacturing, but the existing 802 started late and targeted much more advanced features)

I'd argue Jumo might have been better of being the one to handle the coupled engine development anyway. Develop a coupled Jumo 211 derivative, don't bother with the 222, and leave DB to focus on DB 601/605 and 603 development and don't bother with the 604 either. (and of course continue Jumo 211/213 development)

 

[SpicyJuan11]

There's also the pre-war 2000 hp class 18 cylinder Bramo 329 that might have developed into something compelling in the vein of what the 606 and Jumo 222 were targeting initially had BMW not canceled development after their merger with Bramo. (admittedly, an earlier, more conservative 18 cylinder BMW 801 derivative might have made as much or more sense given the common bore/stroke and potential common tooling with the 801 for easier manufacturing, but the existing 802 started late and targeted much more advanced features)

I'd argue Jumo might have been better of being the one to handle the coupled engine development anyway. Develop a coupled Jumo 211 derivative, don't bother with the 222, and leave DB to focus on DB 601/605 and 603 development and don't bother with the 604 either. (and of course continue Jumo 211/213 development)

Was the Jumo 212 ever produced? All I have managed to find on it is that it was a proposed powerplant for the He 177.

 

[kool kitty89]

As far as I know it was only a paper design, so unproven, but the Jumo 211 at least SEEMS like a safer bet to get a working twin-V12 going. (and probably less trouble than the 222 too) The vertically oriented twin-V arrangement that came up in the Typhoon thread (regarding the Peregrine) seems like it'd work better than the DB arrangement too. (mate an upright V to an inverted V at the crankcase, keep independent crankshafts and cylinders, just sharing the lubrication system and an integral crank case with the two crankshafts geared together -a more compact arrangement and simpler exhaust ducting with potential for ejector stacks on all 24 cylinders)