Japanese engines with water-alcohol injection

[Ivan1GFP]

Hello DarrenW,

Mitsubishi Kasei 23 as installed in J2M3 Raiden was supplied with
390 Liters Fuel in Main Tank
90 Liters Fuel in each Wing Tank
120 Liter Water-Methanol Tank.
and
Up to 400 Liters Fuel in Drop Tank.

I do not have specifications as to when the water injection was turned on but it is probably in one of books somewhere..... If only I could read Japanese.


Hello Tomo Pauk,

My interpretation of those same tables is a bit different from yours.
Please observe that the Take-Off ratings also correspond to the same Manifold pressure but do not have asterisks. The asterisks denote a calculated or projected value and are only present for WEP throttle settings ABOVE Sea Level.
Other numbers as a general note (not otherwise specified) were taken from operating manuals.
To me, this means that the Japanese in their manuals did not specify any WEP / Emergency ratings at all beyond Take-Off power at Sea Level.
....So, although the pilot probably could actually use a WEP rating in combat, it wasn't listed in the manual.

- Ivan.

 

[tomo pauk]

...
I do not have specifications as to when the water injection was turned on but it is probably in one of books somewhere..... If only I could read Japanese.
- Ivan.

Perhaps you can post a picture or two?

 

[Ivan1GFP]

Perhaps you can post a picture or two?

Between Firewall and Cockpit
60 Liter Oil Tank
120 Liter Water Tank
390 Liter Fuel Tank.

 

[DarrenW]

That's all very good information gentlemen, thanks for the input.

 

[DarrenW]

By my understanding, the Japanese did not use Emergency Power in their tests for maximum speed.

Did a source document describe it to be this way or are you just going by the engine technical data you have, showing at what points WEP was engaged and not engaged?

 

[Ivan1GFP]

Did a source document describe it to be this way or are you just going by the engine technical data you have, showing at what points WEP was engaged and not engaged?

Hello DarrenW,

After seeing this mentioned a lot in forums and other discussions, and seeing translated documents that lack Emergency Power ratings at altitude, I am pretty convinced this is the case. The problem here is that I do not read Japanese and depend on others to do the translating for me. Often it is my Wife and I note down the details (in my data sheet) but don't necessarily note down the source document. (Sometimes the title isn't a nice clean translation because my Wife can only read the Kanji and she doesn't really know aeroplane terminology.) It gets bad enough that I have actually had her translate the same tables several times for me to get different pieces of data because the meaning may become more clear when combined with other data and also because interest changes from one aeroplane to another pretty quickly.
This is the main reason I keep data sheets on the aeroplanes that I keep coming back to. It makes no sense to sift through the same documents over and over again.

One good indication that what I am telling you is correct is to look at the data from TAIC tables such as the one posted by Tomo Pauk.
Read the comment I made about it. Read the description of notations which explains how the data was gathered and what the asterisk actually means. You may come to the same conclusion as I did.
The rest of the report is actually on this site because here is where I found it, but I don't know where exactly it is hiding.

- ivan.

 

[DarrenW]

After seeing this mentioned a lot in forums and other discussions, and seeing translated documents that lack Emergency Power ratings at altitude, I am pretty convinced this is the case.

Sounds like a reasonable conclusion to make.

 

[Shinpachi]

Interesting talks, gents.
As a common knowledge, engine operation rules are shown in a Mitsubishi manual like this -
Engine powers
@ Cruising : Continuous operation for hours ok
@ Nominal : within 30 minutes
@ Take-off/Emergency : within 1 minute
@ Diving max : within 30 seconds
Take-off power can be understood as emergency power too.

 

[DarrenW]

@ Take-off/Emergency : within 1 minute

Please excuse my ineptness, but does this mean that WEP should only be utilized in 1 minute intervals?

 

[Ivan1GFP]

Please excuse my ineptness, but does this mean that WEP should only be utilized in 1 minute intervals?

The note below can be found at the beginning of the TAIC Report on Japanese Engines.
My interpretation is that there isn't in most cases an "(War) Emergency Power" rating listed in the manual but don't be real surprised if a Japanese pilot decides to use it anyway.
This was noted in a report about the Ki 43 Hayabusa and its very high "Flash Performance".
I paraphrase here: "Their pilots routinely exceed maximum throttle settings and seem to get away with it."
Some engines were probably a lot more tolerant of this than others.
The Middletown test of Ki 84 documented an engine test (on the bench) at very close to Take Off power on page 162.

- Ivan.

 

[Shinpachi]

Perfect, Ivan.
Thanks.

 

[DarrenW]

Mitsubishi Ha-112-II rating

Thought I'd include a link to this thread with information about this late-war Japanese engine (Army version of the Kinsei, I presume) that also used the water-alcohol injection system.