Data Base: Japanese Aircraft Engines

[Shinpachi]

You are welcome, Aurum.

1. There is/was always prototype or experimental type before formal production.
Production period would have been different.

2. The page says Gnome Rhone sample was a copy of Bristol Jupitor clearly.

3. Page 66 attached says -
"It was a common knowledge at the time that idealistic stroke is 10% longer than bore diameter. Nakajima would have avoided the 190mm of Jupiter as it seemed too long. However, there was another possibility that Nakajima simply referred to the 6"3/8(161.9mm) of Hornet."
Even author does not know exactly.

 

[Vincenzo]

afaik the K series of G-R was a development of bristol titan

 

[Shinpachi]

Thanks for your information, Vincenzo!

 

[msxyz]

Does anybody have some hi-res / good looking photos of the Mitsubishi A21 (Ha-50) which was unearthed a few years ago and now it's displayed at the Narita museum?

Also, I wanted to thank Shinpachi for having scanned that book about Mitsubishi engines. It's a wonderful trove of informations.

 

[Shinpachi]

You are welcome, msxyz!

 

[Nick Sumner]

Does anybody have some hi-res / good looking photos of the Mitsubishi A21 (Ha-50) which was unearthed a few years ago and now it's displayed at the Narita museum?

Japanese

 

[Aurum]

Неу guys! There is a serious contradiction!!!
Ha-50 (A21) was Mitsubishi design with bore/stroke=150/170 mm. But according to the link Japanese in Narita airport Ha-51 is exhibited that was NOT Mitsubishi but was Hitachi design and had bore/stroke equals to Sakae-Homare i.e. 130/150 mm.

So who is mistaking??? Eather that is mighty Mitsubishi Ha-50 "Kasey 22-cyl", or Hitachi Ha-51 "Homare 22-cyl"!!!???

 

[tomo pauk]

Hi,ž
Any hope to see the tables power graph from the picture above in high resolution?

 

[razor1uk]

Cracking info so far guys, loving the tech details
Aurum, might you be able to link a larger image size for the 'poster/placard' you attatched posted above?

 

[Aurum]

Thats only I have

 

[sibboh]

Do anyone know if there are more informations about japanese engine power output and related boost (with a focus on continuous output)?
I'm interested in particular to: Kotobuki, Shinten 11, Shinten 21, Ha.5/Ha.41/Ha.109 (Ha.34), Sakae, Zuisei, Homare, Kasei, Kinsei, Ha.104 (Ha.42), Ha.211 (Ha.43) and the family developed by the DB600 series (Ha.40/Ha.140, or Ha.60). I'd like to have enough data to understand their evolution from the first to the latest versions. Excuse me. Probably expecting too much. But I hope for your help.

 

[Segment]

Where i can read info about japanese engines fuel consumption?

 

[Shinpachi]

The fuel consumption depends on the airframe.
I have not seen such lists for the Japanese aircraft.

For your reference from my own calculation - 2.71km/L(or 0.37L/km) for the A6M2b and 2.13km/L(or 0.4L/km) for the Ki-43-I.
Engine performances were basically same.

 

[Segment]

Thank you, Shinpachi. But i am talking about gramm per hp fuel consumption. Obviously that consumption not depends from airframe, but only from engine current power and regime.
In your calculation I do not understand for what speed (or engine power) are those numbers.

 

[msxyz]

Неу guys! There is a serious contradiction!!!
Ha-50 (A21) was Mitsubishi design with bore/stroke=150/170 mm. But according to the link Japanese in Narita airport Ha-51 is exhibited that was NOT Mitsubishi but was Hitachi design and had bore/stroke equals to Sakae-Homare i.e. 130/150 mm.

So who is mistaking??? Eather that is mighty Mitsubishi Ha-50 "Kasey 22-cyl", or Hitachi Ha-51 "Homare 22-cyl"!!!???

Considered the sorry state of the recovered specimen exibited in the airport, it's difficult to tell from the pictures available. In the book, "romance of the engines", there's a picture of a working prototype of the Ha-51 and a brief description saying that development continued post war at the request of the Americans.

Hitachi had some experience with radial engines, but not to the extent of Mitsubishi and Nakajima. It's interesting that they also offered a radial engine with the same unit displacement of 130x150mm as the Nakajima Sakae and Homare; I think it was called the Amakaze and delivered, in it's best variant, about 600 hp.

I wonder how could Hitachi embark in the construction of a 22 cylinder radial with so little experience and even aiming at a specific power of more than 50 HP/liter! The troublesome Homare could reach it in trials using high octane fuels and alchool injection and these were carefully assembled prototypes. Production engines had 1300 hp and yet they broke easily due to the bad quality of bearings and to the overheat (cooling fins had to be redesigned in late variants).

Part of me wants to believe it's a Ha-50 hastily concealed to hide the program from the vengeful eyes of the occupants...

 

[Ivan1GFP]

Hello All,

From Famous Airplanes of the World and other sources, I have the following data:
Ha-40
Take-Off Boost Pressure +330 mm
Take-Off Power 1175 - 1180 HP @ 2500 RPM

Sea Level Military Boost: +240 mm
Military Power 1040 HP @ 2400 RPM @ Sea Level
Military Power 1100 HP @ 2400 RPM @ 4200 Meters altitude


Ha-140
Take-Off Boost Pressure +380 mm
Take-Off Power 1500 HP @ 2750 RPM

Sea Level Military Boost: +380 mm <-------- I am certain this must be a misprint.
Military Power 1350 HP @ 2650 RPM @ Sea Level
Military Power 1250 HP @ 2650 RPM @ 5700 Meters altitude

Does anyone here have the correct military boost pressure for the Ha-140 engine?
I believe it should be a lot lower than the take-off rating.

Thanks.
- Ivan.

 

[mikec1]

Greetings Shinpachi;



Lots of hard to find engine information.....................

The better the information, that we can provide the builders with, the better models we should
see in the future. When I was younger, I would loved to have some of the Reference material
that we have available to us now days.


Thanks for sharing,


Mike

 

[razor1uk]

With regards to some of the earlier posts about the P&W influence, I am led to believe (from onsite pdf's about allied inspection analysis of recovered enemy engines - there's one about a crash damaged Sakae) that this was related not to whole/total copies of engine design, but more towards material specs used also design specifications of components within a Japanese engine design.

Some references also suggested that some individual parts details were more similar to G&R /or Bristol practises as well.

Basically the specs, details and design of components were selected from those that best fitted Japanese: metallurgy, casting forging styles, design ideas knowledge acquired (both indigenous and from foreign licences), manufacturing and assembly methods and the ability for rectification, repair and operational usages.

The report said IIRC that while nothing special, the inspected design did well to combine the best of the rest details into a relatively good product. I'd imagine that other engine manufacturers shared and borrowed some specs details from others too, and when forced to by the brass/government with regards specific knowledge/skills.

On an related note, the late Mr. Soichiro Honda (yes, that pre-eminent 'engine'ering guy) worked in his garage making piston rings for Mitsubishi during the war (at some point), apparently, he spent much time perfecting his garages/company's rings for wear performance (likely to be forge welded mix of ferrous alloy/metal ) that were highly regarded by Mitsubishi. (According to a History of Honda; GP Racers book)

 

[Aurum]

By the way I've found small mistake in the table of Nakajima's engines data form the known book. It regards to my favorite engine's line Ha-5/41/109. I've been interested what was difference between Ha-5 Ha-41 engines what gained significant power to the last one.

According to normal t-o boost figures of Ha-5 engine it was not fitted by mechanical supercharger. So next data regarding its impeller ratio impeller diameter belongs not to Ha-5 but to Ha-41 engine.
I marked it by blue arrow dash.

 

[tomo pauk]

Thanks.
The Ha-109 did not have two stages, it did have two supercharger speeds. Hence the '1st stage' remark should be changed to '1st gear', same change for the '2nd stage' remark.