Data Base: Japanese Aircraft Engines

Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules

Hi,

Does anyone out there have any scans of the original manuals or plans or technical drawings for the nakajima ki43 Oscar/Hayabusa.

Nick
 
I lately became interested in an issue with negative G's and inverted flight and if it affected the Japanese engines.
However both pilot statement and original documentation say that it was not a case, the earliest source I managed to find, was Type 99 950 HP engine manual (Ha-25 engine) and at page 25 it indicates:
"At the special flight situation drastic maneuver often excessively change the gravity applied on vaporizer hence float mechanism can work improperly, leaving composite gas density thinner and eventually stops the engine, so this vaporizer has worked out for adapting to those situation by setting fuel control devices such as gravity valve and flow restriction valve to make automatic fuel supplement available in order to facilitate the operation of engine during any kind of gravity change. "
This was my rough translation of this part :

Last part indicates that issue not only was known but is solved.

And indeed both Hayabusa or Zero pilots, including Saburo Sakai confirm that it was not a case.

However is it know, I'm especially asking Shinpachi since he might have first hand data, if that was a problem for earlier models like A5M4 or Ki-27 ?
 
Nakajima's Automatic Mixture Control carburetor was a breakthrough for the greater maneuverability of the Ki-43 and the A6M.
The mixing ratio of air and fuel was manually adjusted according to the altitude till A.M.C. system was adopted.
 
Yes. I know this, and believe me, I'm impressed.

But what about previous engines, like Nakajima Ha-1b (Kotobuki 41) or Nakajima Hikari. Or even Mitsubishi Zuisei. I wonder if before there were any designs or trials to overcome gravity issues and sudden inverted maneuvers, to prevent engine cutoff.
 
OK, Hiromachi, Japanese engine manufacturers were using imported carburetors from UK and France until Nakajima Aircraft developed its own A.M.C. products in the late 1930s and even Mitsubishi was to purchase Nakajima's A.M.C.
I guess those reliable western carburetors were all equipped with the manual adjustment system at least.

Just for your curiosity
 
That doesnt give us much unfortunately, but thank you Shinpachi.
I guess those reliable western carburetors were all equipped with the manual adjustment system at least.
Considering that Hurricanes and even early Spitfires were prone to cut off in rapid negative G maneuvers, which is even portrayed in modern flight simulators, I would guess that Japanese machines were also.
Although finding more details on what French and British carburetors were used on various Japanese engines might give us something. Maybe French Aviation was in this area step ahead of British ?

I will talk with my friend, who knows more about French constructions and see what I can find. Eventually, will put it here.
If you would find anything on specific models and engines fitted with that models of carburetors that would also be great
 
This is outstanding Shinpachi. I will read it before next reincarnation and in next life we will talk about it ^^
 
You know, I got a Japanese friend. He sometimes translates for me a page or two. I'm sure he will be happy when I will show that to him
 
Hi Micdrow
I doubt it is headrest because of the three mounting points which are in slots which indicates a need for a degree of accurate alignment. The tops of the 3 arms are what you would expect to see for shock mounted components.
I had a good look at Mikesh's book on Japanese Aircraft interiors and found nothing remotely like this part in the Ki-43 however with any aircraft that was built in large numbers there were always many variants and even local modifications
 
Hmpf.
Shinpachi, how much data do you have on the Nakajima Ha-44-12 engine with Hitachi Ru-204 turbosupercharger ? This is the powerplant of Ki-94-II.
I lately discovered this :
Tatsuo Hasegawa, Ki-94
At the bottom of the page one can find the link to article: " 12. Hasegawa, T. Full-fledged high-altitude air-defence fighter aircraft Ki-94. The World's Aircraft 1956: 6(5);100-107 and 1956:6(6); 94-95 (世界の航空機、鳳文所林、港区 "
http://www.geocities.jp/pinealguy/tatsuo/worldaircraft1956final.pdf

It gives all the estimations on the performance and also engine power.
According to article table it should be :
"Engine
Name Ha-44 mod.12 with Ru-204 turbosupercharger
Nominal HP 2,070 HP/ 0m, 2,260 HP / 10 km, 2,100HP / 12km, 1,750HP / 14km
Take off HP 2,400HP / 2800 RPM
Reduction ratio 0.43055 "

Those data are different from what I could find in the internet and other books, including Japanese titles:
Take-off Power - 2450 HP / 2800 RPM
Nominal - (HP / alt (m) / RPM)
2350/1100/2700
2200/4400/2700
2040/11000/2700

However if I would have to choose between those ... I would rather accept the values given by Mr. Hasegawa since he was engineer in Ki-94 program and other values come from unknown to me source, however are replicated by many other publications.

If you could take a look into your data Shinpachi maybe something could be revealed
 
There are variety of data for the same engine but I think I have posted the most reliable Nakajima Aircraft Engine data in this thread just five years before.
 
I managed to contact Mr. Akio Hasegawa who lives in Tokyo. He is a son of Tatsuo Hasegawa, a chief of fighter designs in Tachikawa Aircraft Corporation. His main achievement was Ki-94 high altitude interceptor. In 1950's he wrote an article about Ki-94-II also adding various graphs and tables.

One of them contained performance of Nakajima Ha-44-12 with turbosupercharger Hitachi Ru-204 and so I wanted to drop it here. It indicates rated power, at 1st gear (top curve, starting at 2070 HP) and 2nd gear (mid curve, starting at 1700 HP). The curve at the very bottom is consumption of HP by cooling fan (if I understood it properly).
 
Hello all,
I am new on this forum. I am currently writing a detailed study about French aero-engines Lorraine-Dietrich (in fact "Lorraine" only from 1928 onwards). I have all the necessary data regarding the engine designs and their manufacture in France but I desperately need some assistance regarding their manufacture under licence in Japan.

Briefly, there are two periods, related to two different types of technology.

1st period: the 1920s, with WWI-style engines (OHC, 2 valves in V, external visible distribution, twin-cylinders)
Three Lorraine engines were made under licence in Japan:
- the 400hp V12 12Db (120x170), made by Hiro
- the 150hp W12 12Eb (120x180), made by Nakajima and Aichi
- the 450hp W12 12Ed (120x180), identical to 12Eb but in geared version
It seems that the Japanese versions were identical to the original French ones, so nothing complicated (but any additional info such as precise quantities is always welcome).

2nd period: the 1930s, with modern engines (OHC or DOHC, 4-valves, hidden distribution, monoblock cylinder-benches)
This is far more complex. In 1929-1930 Lorraine released a new family of three engines:
- the 600hp W12 12F Courlis (145x160), OHC
- the 700hp W18 18G Orion (125x180), initially OHC, then a further DOHC version
- the 500hp V12 12H Petrel (145x145), initially OHC, then a further DOHC version
I have read that Japan had purchased the rights to manufacture these three engines. However it seems that they were not manufactured identical to the French versions but with Japanese adaptions.
Hiro has manufactured several engines which seems to be based on initial Lorraine designs:
- type 14, type 90, type 91, type 94
Unfortunately between Mikesh Abe's "Japanese Aircraft 1910-1941", wikipedia, and other sources, it is totally confused, none of them is providing the same information. Therefore, could someone help me in identifying, via reliable sources, for these four Hiro engines, what was their configuration (number of cylinders, dimensions, distribution... of course if pictures availble that would be perfect!) and possibly history? Should you know any existing source dealing with this subject...

I rely on you as, for such a precise subject, I am afraid that if the answers can not be found on this specialised forum, they will not be found anywhere else! In any case, be sure that the source of any info will be credited in my study.
Thanks very much to all in advance for your assistance.
Regards from Toulouse (France),
Sebastien
 

Users who are viewing this thread