Japanese Radial Engine Developments shared with Germany

[JuniorJarhead09]

I know they shared info and that Germany sent He-112 and bf-109E to japan and a fw190. What could the Germans have learned from some efficiancy working around problems uniquly, could they have applied it to any of there aircraft or potential ones, aforementioned Fw-187, what about other hypotheticals, PM-1 being developed ealier say 1942. It wouldn't have helped much but maybe a little bit.

I'm of the opinion of V12's and radials.
don't waste unnecessary materials on other aircraft especially of the bomber variety and don't make the gustav gun also the junkers 335 transport. no 4-210's no 410's doniers, No Ju-87's.
wooden planes production maybe ad steel rivets with plates on the non moving surfaces on the wings



what japanese developments would have helped the bmw-139 what about the BMW-801.

I would not mess with the DB-603.

The Arado 234 I would have farther developed as it first flew quite early, fast bomber and low strike ambushes.

I would have a twin engine similar to the ju-88 but smaller as a reconnaissance / radar,
Have a designated night fighter like a Ta-154 or something of a type,

 

[tomo pauk]

Welcome to the forum.

I know they shared info and that Germany sent He-112 and bf-109E to japan and a fw190. What could the Germans have learned from some efficiancy working around problems uniquly, could they have applied it to any of there aircraft or potential ones, aforementioned Fw-187, what about other hypotheticals, PM-1 being developed ealier say 1942. It wouldn't have helped much but maybe a little bit.

By 'PM-1', you probably mean P1Y Ginga?

I'm of the opinion of V12's and radials.
don't waste unnecessary materials on other aircraft especially of the bomber variety and don't make the gustav gun also the junkers 335 transport. no 4-210's no 410's doniers,

This quoted part might use the proof-reading. No offense.

No Ju-87's.

When, and what to make instead?

what japanese developments would have helped the bmw-139 what about the BMW-801.

The BMW 139 was judged as a lemon probably even before Fw 190 took 1st flight, BMW redesigning the 139 into the 801 rather fast.
What BMW 801 might've used is the Japanese supercharger, seems like Japanese were earlier to make the improved S/Cs for their in-service radials than BMW did so; granted, RLM dropped the ball by not insiting into the development of the much-improved BMW 801E.
Mitsubishi managed to have water-alcohol injection for their engines already in 1943 (a thing where BMW was not good at, not at all) - couple this and better S/C and Fw 190 is still viable even against the P-47s above 20000 ft, let alone under that altitude and against anyone.
Japanese big radials were also much lighter than the 801, but there is probably no way for the 801 to loose even 50, let alone 100 or 150 kg. However, the German V12s will give the good run for their money to the Japanese radials wrt. the power, and be better wrt. the drag.

Supercharger system from Ha-102 or from the Sakae 21 would've much improved the BMW 132, and somewhat the Bramo 323.

I would not mess with the DB-603.

Care to elaborate?

The Arado 234 I would have farther developed as it first flew quite early, fast bomber and low strike ambushes.

Jets were certainly promising for the LW that found themselves out-matched and badly out-numbered by some time of 1943.

I would have a twin engine similar to the ju-88 but smaller as a reconnaissance / radar,
Have a designated night fighter like a Ta-154 or something of a type,

Yes, something smaller, sleeker and lighter than the Ju 88 was needed, both as a recon bird as well as a night fighter. Ta 154 fits in these 3 categories, what was wrong with it was mostly the timing.

 

[Shortround6]

, No Ju-87's.

When, and what to make instead?

Tomo's question is important. The Ju-87 first flew in 1935. The D3A (Val) did not fly until Dec 37/Jan 38.
When do the Germans and Japanese start sharing things?
And/or when do the Japanese start to exceed the German technology in the 1930s. A lot flowed from the Germans to the Japanese in the 1930s and at some point the Japanese did pass out the Germans with some designs.
Yes the Ju-87 became obsolescent early in the war, but it's replacement never showed up and the Ju-87 was useful for quite a while.

wooden planes production

Wooden planes need a lot of work, that is to say they need a lot of work on structure, and they need careful application. Looking back we can see many of the problems which were not as obvious in the late 30s or early 1940s. They had making wooden aircraft since 1903 so why not continue?
Basic problem is the weight needed for structural strength desired. Aerodynamic loads go up with square of the speed. Low speed aircraft can easily be made of wood with very little weight penalty. Trying to build 300mph+ aircraft from wood gets a lot harder. Also turns out that getting good quality wood is a lot harder than many people thought. Also turns out that glue/adhesives are a problem. The number of really successful wooden combat aircraft were very small. Please note that the British Mosquito was a quasi composite construction.
Thin layers of veneer with a balsa core giving thick but light fuselage skin and smooth surface. But you need access to balsa wood (Ecuador?). Many WW II fighters that were made of wood (Russian) were several hundred pounds (or kg) heavier than an equivalent metal plane. A wooden plane beats no plane but the Germans managed to build 10s of thousands of metal planes. Maybe they should have worked a little harder at making more effective planes (when should the 109 replacement have shown up?)

 

[JuniorJarhead09]

ju-87 didn't need non retractable landing gear. tail gunner had a pretty bad FOV, if you wait 6 months or a year maybe 2 before asking for that type of design, a capable strike aircraft that will be lighter more maneuverable and more ergonomic.

DB603 was started and stopped multiple times, if they don't stop at all they can have quicker improvements,
everything was so political and things could have been streamlined way more efficiently.

I was aware that germans spent resources and time on MANY airframes but when I saw the list I was shocked.

PM-1 I was referring to the Pyorremyrsky, It didn't fly till november 45. No reason it really couldn't have been hypothetically built earlier. what if they decide to use it and make it with metal or aluminum.

what improvements would the japanese designs have seen on german engines? redesigned aircraft?
less drag? superior speed? improved agility? longer range?

By 'PM-1', you probably mean P1Y Ging?



This quoted part might use the proof-reading. No offense.


When, and what to make instead?


The BMW 139 was judged as a lemon probably even before Fw 190 took 1st flight, BMW redesigning the 139 into the 801 rather fast.
What BMW 801 might've used is the Japanese supercharger, seems like Japanese were earlier to make the improved S/Cs for their in-service radials than BMW did so; granted, RLM dropped the ball by not insiting into the development of the much-improved BMW 801E.
Mitsubishi managed to have water-alcohol injection for their engines already in 1943 (a thing where BMW was not good at, not at all) - couple this and better S/C and Fw 190 is still viable even against the P-47s above 20000 ft, let alone under that altitude and against anyone.
Japanese big radials were also much lighter than the 801, but there is probably no way for the 801 to loose even 50, let alone 100 or 150 kg. However, the German V12s will give the good run for their money to the Japanese radials wrt. the power, and be better wrt. the drag.

Supercharger system from Ha-102 or from the Sakae 21 would've much improved the BMW 132, and somewhat the Bramo 323.



Care to elaborate?


Jets were certainly promising for the LW that found themselves out-matched and badly out-numbered by some time of 1943.



Yes, something smaller, sleeker and lighter than the Ju 88 was needed, both as a recon bird as well as a night fighter. Ta 154 fits in these 3 categories, what was wrong with it was mostly the timing.

 

[tomo pauk]

Wrt. the 'wooden planes' - Germans will need to make a conscious and early decision to make these in the 1st place. Making the trainers, transports and light/auxiliary 'wooden' (plus canvas, plus steel) aircraft can yield both with good and perfectly useful aircraft in thousands, while saving the light alloys for the frontline types.

 

[Shortround6]

what improvements would the japanese designs have seen on german engines? redesigned aircraft?
less drag? superior speed? improved agility? longer range?

Just about everything is a trade off. And sometimes it is a 3 or even 4 way mix.

Less drag? Superior speed?

Pretty much the same thing. Less drag means more speed for the same installed power. Granted you can stuff in more power for more speed and keep the same drag (mostly).
More power usually means more cooling drag (bigger radiators or more air through the cowl) but cooling drag is a only part of the total drag so things usually get better.

However.
Improved agility?
Gets a little more complicated as agility is sometime measured/rated in several directions. Roll is one, pitch change is another. Turn is often measured/talked about turn gets very complicated. Here we get into trade offs. A big wing is usually good for turn, low wing loading. But a big wing is not so good for roll and it is not good for speed (higher drag).
We can also get into the shape of the wing. Long skinny or short and fat (cord) and also with thickness.
Spitfire wing shape is a classic as they got rather different results with just a small difference in changes to the wing tips. You could change the wing from clipped to extended by bolting the wing tips to the same wing at the last real rib.
Curtiss Hawk 75-87 is another interesting progression. The radial engine light weight Hawk 75 was noted for it's maneuverability/agility compared to a MK I Spitfire. The later P-40s, using the same wing shape/size but gaining over 2000lbs and longer nose lost a lot of the 'agility'. Roll was still good but not as good as the earlier plane.

Sometimes good turn came at the expense of fast roll rate.
The vaunted good turn of some of the JAAF fighters came at the expense of high drag. Even combat flaps cause drag when used. Perhaps that can be made up for with a powerful engine to combat the drag and/or with good acceleration to quickly regain lost speed. The slats on the 109 don't work like a lot of people think. They only work at a very high angle of attack which is a high drag condition to begin with.

Some air forces had different priorities/flying styles.

Long range?
Any designer worth his T-square or slide rule knew how to get long range (more fuel) but more fuel means more weight and more weight means less speed/slower rate of climb, unless you leave something/s else out. Like guns/ammo or armor/BP glass or fuel protection.

There were NO Japanese secrets. Just different choices. Likewise there were NO German secrets. Just different choices.

 

[tomo pauk]

ju-87 didn't need non retractable landing gear.

Double negatives can make a sentence awkward

tail gunner had a pretty bad FOV, if you wait 6 months or a year maybe 2 before asking for that type of design, a capable strike aircraft that will be lighter more maneuverable and more ergonomic.

What source says that the tail gunner had a pretty bad FOV, and compared with what similar aircraft?
Perhaps you might want to decide whether Germans should wait 6, 12 or 24 months? Movable goal posts rarely make for a focused discussion.
Or perhaps not wait at all, and go with some other aircraft type? LW/Germany were on an accelerated time table already by 1936.

PM-1 I was referring to the Pyorremyrsky, It didn't fly till november 45. No reason it really couldn't have been hypothetically built earlier. what if they decide to use it and make it with metal or aluminum.

An easy way for the LW to have the DB 605-powered fighter without the many shortcomings that Bf 109 had was to slap the 605 engine on the Fw 190. But indeed there is no reason why the German Pyörremyrsky-equivalent was not made much earlier.

what improvements would the japanese designs have seen on german engines? redesigned aircraft?
less drag? superior speed? improved agility? longer range?

Japanese engines were pretty light for the power they were making, so their better engines on the German fighters would've improved the power-to-weight ratio -> RoC can be better, ditto for horizontal maneuverability & agility. Japanese radials would've fit nicely on many German 2- and 3-engined aircraft, again benefiting from the light weight. Homare* on the Fw 190 would've been great, especially considering that Germans had high octane fuel to spare. Better fuel mileage vs. BMW 801.
Ha 109 on the Fw 190 = a light and maneuverable Fw 190, especially if the MW 50 can be incorporated.
Homare's or 20 series Kinsei's S/C on the BMW 801D = power probably close to the 801E or the 801S.

Trick is to have the Japanese engines to be made in Germany, and fast and en masse - a lot would've depended on the foresight and good will at both sides.

DB603 was started and stopped multiple times, if they don't stop at all they can have quicker improvements,
everything was so political and things could have been streamlined way more efficiently.

I was aware that germans spent resources and time on MANY airframes but when I saw the list I was shocked.

Yes, German war procurement strategy was with a lot of shortcomings.

 

[Shortround6]

Ju-87B rear gun position. Earlier and later versions were different.

Lot of argument over useful traverse on many of these aircraft.

Fairey Battle. Now try and aim/fire like that at 320kph or faster.
A lot of difference in firing angles between possible and probable.

Keeping the rear gunner from getting frostbite may have been an advantage.

 

[Howard Gibson]

I'm of the opinion of V12's and radials.
don't waste unnecessary materials on other aircraft especially of the bomber variety and don't make the gustav gun also the junkers 335 transport. no 4-210's no 410's doniers, No Ju-87's.

What was wrong with the Ju-87? Single engined light bombers like the Ju-87, the Val, the Dauntless and Fairey Battle require air superiority. Without it, they get massacred.

wooden planes production maybe ad steel rivets with plates on the non moving surfaces on the wings

Were the Japanese good at wooden aircraft? The wooden Frank was hundreds of pounds heavier than the aluminium Frank, and they got it working in August 1945.

what japanese developments would have helped the bmw-139 what about the BMW-801.

The Germans liked "inline" engines. Kurt Tank got away with a radial because the DB-601s were not available. Which Japanese engine would be a good substitute for the BMW-801?

I would have a twin engine similar to the ju-88 but smaller as a reconnaissance / radar,
Have a designated night fighter like a Ta-154 or something of a type,

They had the Ta-154 as a designated night fighter. They could not get it working. Again, Japanese expertise at aircraft woodworking, such as it was, was not going to help.

 

[tomo pauk]

The Germans liked "inline" engines. Kurt Tank got away with a radial because the DB-601s were not available. Which Japanese engine would be a good substitute for the BMW-801?

Tank probably choose the radial because it (initially the BMW 139) was supposed to give about 40% more power over the DB 601A, while being very light for that power. Light engine allowed for a small wing (Fw 190 V5k and earlier were with a smaller wing than the Bf 109), that was also of then-modern profile.
Tank counted on the 'trick nose' and the faired air intakes to lower the drag, and on the exhaust thrust that was also being better than what the DB 601A was offering. Much better power and exhaust thrust vs. the expected meager weight (in June 1938, 2750 kg loaded was expected!! ) was bound to result with the excellent RoC.

BMW 139 being a dog necessitated the major redesign, thus the 801 came about, together with it's increased length and much greater weight, that in return required a bigger wing on the 190.

As for what Japanese engine on the Fw 190, the Ha 41 and 109 + better exhausts would've been a good fit. Also the Homare. The Kasei should not be to bad fit either; Fw had the 190 planned to be powered with the still bulkier R-2600, that never materialized. With the lightweight Japanese engines early on on the 190, the small wing would've sufficed. japanese engines would've made another 10% more power via use of bigger valve overlap if the direct fuel injection is used. Some extra power should be gotten by using high octane fuel.

But again, expecting that Germans hang their hat on what Japanese might provide seems like a very long shot.