Some stuff about Tank's rare fighters

[wiking85]

And you come up with a hypothetical 603 in 41 that will run on the same power level and reliability of the real 603 in late 43 which is unlikely at best, more highly questionable. DB did not have endless engineering capacity, without sacrifying other projects they couldn't simultaneously work on 600/601, 603 and 605.
The 603 would not have started with pressurized water cooling for sure as DB had no real experience with it (which it gained from the 601E). A lot of effort was made to improve the fuel burn efficiency by changes to the pistons and related components, AFAIR this helped with the 601N used in the Bf 109F but most changes again appeared with the 601E.

I didn't say the 603 would have 1943 numbers in 1941; if anything I think 1600hp would be reasonable by 1941, with 1750hp in 1942.

 

[tomo pauk]

Some ideas about turbo DB-603 on the Fw-190. The most straight-forward, but also the most draggier set-up (the one at the bottom of the pic) was actually flown. Other two involved rehashing of fuel tanks.

 

[tomo pauk]

Just ordered this one:

http://www.amazon.de/gp/product/3925480692/ref=s9_simh_gw_p14_d4_i1?pf_rd_m=A3JWKAKR8XB7XF&pf_rd_s=center-2&pf_rd_r=17RJSQ2KNC3HCJ1B5RTB&pf_rd_t=101&pf_rd_p=455353807&pf_rd_i=301128

At 5 euros, by Dietmar Hermann.

 

[OldSkeptic]

The Fuel injection isn't an issue, once you have a working system you can enlarge the injector pumps/plungers for the fuel flow desired. Some of the "cooling" issues are things like a the bigger pistons are harder to cool on ANY engine than smaller pistons. DB 603 used about the biggest pistons of any "common" WW II engine ( Ok only 2 mm bigger than the Russian AM series). Now if you can't keep the center of a 154mm piston to stay 'cool' then expecting a 162mm piston to stay cool is asking a bit much, especially if you are burning more fuel above each sq. cm. of piston area. (12.5% longer stroke). This is plain physics and geometry and has nothing to do with the coolant passages, coolant flow, or pressure the cooling system is operating at. These things can help solve the cooling problem but big cylinders are harder to cool.

Yep, been following this. Very good points. Going to ever larger engines with ever larger pistons created it's own problems. A smaller piston (smaller engine and/or very under square) helps, though you always have piston speed limitations so if too undersquare you lose out on revs. So a design balancing act. And a big heavy piston creates it own rev limitations too.

But I think RR nailed it with a smaller engine with very high boost, which is the direction all piston engines are going towards these days as the optimum. From memory I think they actually got more out of the late models Merlins than they did from the Griffon (which had a lower BMEP).

 

[tomo pauk]

There is more ways to skin a cat. Bigger engines will, in most of the cases, allow for greater take off and continuous powers right from the box.

Just ordered this one:

Die Focke - Wulf Höhenjäger. Vom 1. Höhenjäger zur Fw 190 H: Amazon.de: Dietmar Hermann: Bücher

At 5 euros, by Dietmar Hermann.

The book arrived today - 5 euros for the book, and 3 euros P&P from Germany to Croatia - 1000 km! It deals not just about the Fw-190s, but also the Fw-187 with DB-605s and different armament proposals. The person on another forum posted some stuff from that book, like some graphs and illustrations (links at post #1 here). It has 6 photos of the big-wing (20.3 m^2) Fw-190 prototype, 1st time I've seen that. Ditto for speed and climb graph for the 'Kangaroo', the turboed Fw-190 prototype.
All in all, money well spent

 

[BiffF15]

Tomo,

Do you know if that book was published in English? I have two Harmann books on the Fw-190 / Ta-152 and am wondering if that material is in either one.

Cheers,
Biff

 

[tomo pauk]

IMO, it is not available on English.

 

[Koopernic]

I agree Denniss,

but two points:

The basics for the pressurized water cooling came frome the record engines between 1937-1939 and,
I think without the DB 604 and the coupled stuff DB 606 etc., it was possible for Daimler to develop the DB 603 from 1937 till 1942 ready for mass production and near the same performance and reliability as the DB 603 from end of 1943

Well the DB604 might have kept the Junkers Ju 288 program going, it was a very powerful engine. From my understanding it didn't suffer the reliability issues of the Jumo 222 but had inferior fuel consumption and cruise power despite having the same top power. I really don't know of any single engined fighters ever designed for its use but imagine it would be possible.

Piston engine development in WW2 took some 6 years. You can see that in every major engine program eg R-3350.

The DB603 was slated on the production plans in 1944 in the form of the Fw 190D-14 (DB603EM) and Fw 190D-15 (DB603LA). As far as I know the Fw 190D-9 was essentially a modified Fw 190A-9 with a new firewall for mounting the Jumo 213A and a plug in the tail to lengthen it by 20cm. The Jumo 213A was a 1750hp bomber engine that needed several power boosting methods to make it competitive which were in fact installed basically rich mixture injection to get to 1900hp and then various forms of MW-50 either injected or blown in. The proper Jumo 213 for fighters was actually to be the Jumo 213C which used C-3 fuel from the get go for 1900hp and had mountings for a hollow prop shaft so as to be able to fire a motor canon. (the Jumo 213A was surplus bomber production which is why there was no motor canon on the Fw 190D-9 only the rare Fw 190D-13)

The DB603 engine the Germans had available in 1942 was the DB603A which produced 1750hp and was used on the Me 410, Dornier Do 217M and some prototypes. The fighter version was supposed to be the DB603G which was a C-3 fuel burning fighter engine of 1900hp.

Broadly the engines the Germans had was
DB603A 1750hp (saw service) critical altitude 5500m used 87 octane B4.
DB603AA 1600hp sea level but higher critical altitude (about 8000m) saw service likely in He 219, Used 87 octane B-4 fuel.
DB603G 1900hp but used C3 fuel to achieve this. Seems to have been used on prototypes but never entered production.
DB603E 1800hp advanced engine which combined the low altitude performance of the DB603A with the high altitude capability of the DB603AA. Might have seen service in He 219 and Do 335 but very limited. Used 87 octane B-4 fuel.
DB603EM version of the DB603E which could produce 2250hp through the combined use of MW-50 and C3 fuel. The allied oil campaign seems to have made the Luftwaffe fearful of continuity of its C-3 fuel supply and so production of this engine was cancelled. Otherwise the Ta 152C-1 would have entered service before the Jumo 213E-1 powered Ta 152H.

The DB603L engine added a two stage supercharger, a variant of this, the DB603LA which had lacked the larger inter-cooler of the DB603L was what actually entered service in the Ta 152C-3 because it could do the job without the C-3 fuel on only B-4 fuel while the two stage supercharger gave better high altitude performance as well.

The DB603N had a more elaborate two stage infinitely variable driver supercharger with two mechanical gear speeds. It was to use C3 fuel to achieve 2800hp but of course never entered service.

As far as I can see a Fw 190D-5 modified from a Fw 190A-5 airframe should have been possible in 1942/43: interesting to me is the use of the DB603AA engine which might have given a good interim high altitude fighter. This is where the Germans were caught out as USAAF raids came in at high altitude and aircraft such as the P-38, P-47 and P-51 had much better engines for fighting at 22,000ft+.
The other dark horse is the DB603G. I suspect that issues with the DB603G were one of the key reasons the Me 309 was abandoned as Messerschmidt was forced to experiment with the much weaker DB605.

 

[tomo pauk]

The post-war data about German piston engines:

Daimler-Benz

The DB-603N was also supposed to be turning 3000 rpm, resulting in quite a piston speed (and power, of course). The 603L and 603N were also incorporating the inlet guide vanes, like Jumo 213 series.