DB 603N Engine

[Out2gtcha]

The Dora scoops would look awesome!

[phasephantomphixer]

10 hours ago, curiouslysophie said:

 

I think I’m going to follow a similar route to @Out2gtcha with regard to the cooling intake for the rear engine’s radiator. I will look for some larger air scoops for the supercharger though. I think the quick boost Dora scoops might do the trick. As far as I know, no-one does the Ta-152 ones as a part.

Yes, way back before ZM made their TA-152 I had to scratch an intake for my Vac. kit (here in the LSP article builds) and for the D-11 conversion.

[curiouslysophie]

2 hours ago, phasephantomphixer said:

Yes, way back before ZM made their TA-152 I had to scratch an intake for my Vac. kit (here in the LSP article builds) and for the D-11 conversion.

The ZM kit seems to be the only way to get those scoops, and I’m not sure my scratchbuilding skills are quite that good yet to make some.

[Out2gtcha]

Hope you put up a WIP Sophie, this sounds like a cool project right up my alley

[curiouslysophie]

47 minutes ago, Out2gtcha said:

Hope you put up a WIP Sophie, this sounds like a cool project right up my alley

I definitely will do! My Corsair has just hit the weathering phase so the Do-335 will be coming out of the stash this weekend hopefully! 
I’m trying to learn some 3D modelling to do some custom parts like a later version of the EZ 42 gyroscopic gun sight. Should be a long build I think!

[pvanroy]

No examples of the DB 603 N were ever completed: at the end of the war, this highly advanced design (which incorporated variable valve timing) was only in the early stages of development, and only a single-cylinder engine to test the new cylinder design was built. Four different supercharger lay-outs were under consideration; there exists a four-view outline drawing of a configuration with twin superchargers located on either side of the block. 

 

For anyone interested in the ins and outs of WW II piston aero engine design, I cannot recommend Calum Douglas' work warmly enough: 

 

The Secret Horsepower Race

[adameliclem]

Hi Sophie,

 

Have you considered a chin scoop like the one fitted to the Fw-190 V18?

 

 

The “Kangaroo” was tested with a number of -603 variants, though I don’t think with a DB-603N. An Anteater with a big grin would look pretty wicked. Peter (Airscsle) scratched a beautiful chin intake when he was working on his 1/18 Kanguru.

 

Cheers,

Adam

[curiouslysophie]

11 hours ago, pvanroy said:

No examples of the DB 603 N were ever completed: at the end of the war, this highly advanced design (which incorporated variable valve timing) was only in the early stages of development, and only a single-cylinder engine to test the new cylinder design was built. Four different supercharger lay-outs were under consideration; there exists a four-view outline drawing of a configuration with twin superchargers located on either side of the block. 

 

For anyone interested in the ins and outs of WW II piston aero engine design, I cannot recommend Calum Douglas' work warmly enough: 

 

The Secret Horsepower Race

 

I figured that might be the case and that there wouldn’t be much information on the actual plans. Interesting to know about the variable valve timing. Do you know where I could see those drawings or info on the other layouts?

I will definitely pick up a copy of that book! 

 

11 hours ago, adameliclem said:

Hi Sophie,

 

Have you considered a chin scoop like the one fitted to the Fw-190 V18?

 

 

The “Kangaroo” was tested with a number of -603 variants, though I don’t think with a DB-603N. An Anteater with a big grin would look pretty wicked. Peter (Airscsle) scratched a beautiful chin intake when he was working on his 1/18 Kanguru.

 

Cheers,

Adam

 

That is an interesting idea. I’ll have a look into it, though it would take a hell of a lot of scratch building to modify it in. I will have to try and find that build log! I’d be very interested to know the engine layout of that plane.

[pvanroy]

4 hours ago, curiouslysophie said:

 

Do you know where I could see those drawings or info on the other layouts?

I will definitely pick up a copy of that book! 

 

The overview schematic with the twin superchargers on both sides of the engine is reproduced on p. 393 of Douglas' book. On p. 394, there are detailed engineering schematics for the drive system for a double supercharger on the left side of the engine. Both drawings show a partial outline of a fuselage, which in the first drawing is suggestive of the Do 335, while in the second, it is actually identified as being the Do 335 contour. The book also has engineering drawings of one of the designs of the cylinder head section and timing gear. No further information is given regarding the other supercharger configurations, and it is possible this did not survive the war - it is e.g. also unknown  which cylinder head design was used on the single-cylinder test engine that was built.

 

I can absolutely recommend Calum Douglas' book for anyone interested in the detailed engineering development of piston aero engines - it's simply brilliant.

 

4 hours ago, curiouslysophie said:

That is an interesting idea. I’ll have a look into it, though it would take a hell of a lot of scratch building to modify it in. I will have to try and find that build log! I’d be very interested to know the engine layout of that plane.

 

That scoop on the Fw 190 V18/U1 was for the oil cooler and represents an early DB 603 installation; in later installations of the DB 603, the oil cooler was incorporated into the improved annular radiator matrix, so there's no point in adding it to the front engine of a Do 335 as it would represent a retrograde step, and in any case would do nothing to resolve the cooling issues experienced by the rear engine (in this respect, do note that the Do 335 V1 had a separate oil cooler scoop under the engine, which was eliminated on subsequent machines using the improved radiator design).

 

Edited October 19, 2021 by pvanroy
Added note about Do 335 V1

[curiouslysophie]

27 minutes ago, pvanroy said:

 

The overview schematic with the twin superchargers on both sides of the engine is reproduced on p. 393 of Douglas' book. On p. 394, there are detailed engineering schematics for the drive system for a double supercharger on the left side of the engine. Both drawings show a partial outline of a fuselage, which in the first drawing is suggestive of the Do 335, while in the second, it is actually identified as being the Do 335 contour. The book also has engineering drawings of one of the designs of the cylinder head section and timing gear. No further information is given regarding the other supercharger configurations, and it is possible this did not survive the war - it is e.g. also unknown  which cylinder head design was used on the single-cylinder test engine that was built.

 

I can absolutely recommend Calum Douglas' book for anyone interested in the detailed engineering development of piston aero engines - it's simply brilliant.

 

 

That scoop on the Fw 190 V18/U1 was for the oil cooler and represents an early DB 603 installation; in later installations of the DB 603, the oil cooler was incorporated into the improved annular radiator matrix, so there's no point in adding it to the front engine of a Do 335 as it would represent a retrograde step, and in any case would do nothing to resolve the cooling issues experienced by the rear engine (in this respect, do note that the Do 335 V1 had a separate oil cooler scoop under the engine, which was eliminated on subsequent machines using the improved radiator design).

 

 

I will definitely pick up that book! I am fascinated by the evolution of piston engines, especially during WWII. That book sounds just like what I need for this and some future projects.

 

I had an inkling that was for the oil cooler, and not adding it would save me a great deal of scratchbuilding. I am thinking I may follow a similar route to out2gtcha’s excellent Do 335 build and add an extra radiator system to supplement the rear engines cooling. I have some left over intakes in the spares box which I intend to add with some ducting to show additional radiators, likely in the space above the rear prop shaft.

[curiouslysophie]

On 10/19/2021 at 11:50 AM, pvanroy said:

 

The overview schematic with the twin superchargers on both sides of the engine is reproduced on p. 393 of Douglas' book. On p. 394, there are detailed engineering schematics for the drive system for a double supercharger on the left side of the engine. Both drawings show a partial outline of a fuselage, which in the first drawing is suggestive of the Do 335, while in the second, it is actually identified as being the Do 335 contour. The book also has engineering drawings of one of the designs of the cylinder head section and timing gear. No further information is given regarding the other supercharger configurations, and it is possible this did not survive the war - it is e.g. also unknown  which cylinder head design was used on the single-cylinder test engine that was built.

 

I can absolutely recommend Calum Douglas' book for anyone interested in the detailed engineering development of piston aero engines - it's simply brilliant.

 

I got that book and it is bloody brilliant! I was looking through those drawings and it is interesting. I won’t go for the supercharger on both sides as I don’t want to have to add another scoop to the starboard engine panel. 
I was looking at the dual stage supercharger design and I think I could modify the engine to have it quite easily. 
I am also going to add MW50 & GM-1 systems to the engine. I figured by 1946/47 they would want to push the performance as far as possible.

 

For anyone interested though, reading through various sources, I came across discussion of the rear engine cooling issue, mostly from French evaluation after the war. The issue was largely down to the radiator flap mechanism jamming which would cause the system to be unable to vent heat. I may still add extra cooling inlets to show an additional radiator system (maybe they separated the water and oil cooling?).