Japanese WWII piston engines with fuel injection

[spiralcopter]

It occurred to me that the Japanese license-built HA-40 engines, being a licensed copy of the DB-601A, should have had fuel injection. Did the Japanese show any enthusiasm for this technology elsewhere? One would think that being given the blueprints to a fuel injected engine would be the quickest and easiest way to demonstrate the advantages of the system without the headache of having to figure out how to make it work independently.

 

[GrauGeist]

The Japanese did have fuel injection on some of their later engines, like the Kinsei 51/HA-112.

 

[Shinpachi]

As Dave commented, the fuel injection was not rare in 1945.

Mitsubishi Ha-42

Source: NASM

 

[AerialTorpedoDude69]

IIRC, the Japanese imported BMW 801 engines, which had fuel injection, not just DB 601 engines. These were of more direct use to such engines as the Ha-45-23 since they had implemented direct injection on radials and not inlines.

The TAIC report mentioned that the Japanese had used a carburetor bowl prime on the Homare 21 rather than priming the cylinders as was used in the Double Wasp 2800. However, the Homare 23 appears to have switched to a low-pressure direct injection engine, although the US never got its hands on a Homare 23 AFAIK.

The first Japanese engine to get direct injection MAY have been the Kasei 23 (it got water injection in the 23, definitely). At least, it's said that the Kasei was one of the first Japanese engines to get it. It looks like the Kasei 22 has a carb system although I'm not an expert. (Can anyone else confirm?)

GrauGeist IIRC, Mike Goodwin said that the Kinsei implemented direct injection starting in the 61 series. I think that was first available in 1942, although I don't know for certain.

EDIT: Shinpachi's translated document shows direct injection was actually implemented on the Kinsei 62 series.

 

[GrauGeist]

The Kinsei 51 had redesigned heads, fuel injection introduced and an improved supercharger.

It was Model 61(HA-112-II) that had direct fuel injection introduced.

The fuel system on Models 51, 52(HA-112-I), 53 and 54 was indirect fuel injection.

Going by memory, the 50 series engine was introduced in '41, the 60 series were a bit later.

 

[Shinpachi]

Here is my old work about the Kinsei/Kasei series and variants.
Please refer to each fuel supply column.

Source:

Data Base: Japanese Aircraft Engines

Engine for the Intercontinental Bomber "Fugaku" - challenging 5,000hp

ww2aircraft.net

Data Base: Japanese Aircraft Engines

Thank you. I know this takes time away from your computer work. I saw your work on the A6M in another thread and realize you are in demand so I appreciate your dedication to giving us this information on Japanese engines. I know I couldn't find this anywhere in the US except from you.

ww2aircraft.net

 

[AerialTorpedoDude69]

Shinpachi thank you for sharing! That is a great translation, by the way.


Two things that I find interesting:

1. The translation suggests that the Homare 21 had both fuel injection and water injection, which does not agree with the TAIC report on the Ki-84. It may be that the Homare 21 used indirect injection, which is a form of fuel injection. I think a bowl-prime carburetor is classified as indirect injection since it primes the cylinder heads with fuel. Really interesting.

2. It looks like the Kasei 23 (or Ha-32-11 using the integrated naming system) was the first direct injection engine, unless it used indirect injection. It is not clear to me how to tell the difference between direct and indirect injection systems using the available data.

 

[GrauGeist]

An indirect injection system is a pressurized carburetor (forerunner of throttle-body injection on vehicles), unlike a traditional gravity fed carburetor.

That tends to be a gray area with some historians, who see a pressure carb the same as a gravity carb, but in reality, are not the same.

 

[Shinpachi]

Shinpachi thank you for sharing! That is a great translation, by the way.


Two things that I find interesting:

1. The translation suggests that the Homare 21 had both fuel injection and water injection, which does not agree with the TAIC report on the Ki-84. It may be that the Homare 21 used indirect injection, which is a form of fuel injection. I think a bowl-prime carburetor is classified as indirect injection since it primes the cylinder heads with fuel. Really interesting.

2. It looks like the Kasei 23 (or Ha-32-11 using the integrated naming system) was the first direct injection engine, unless it used indirect injection. It is not clear to me how to tell the difference between direct and indirect injection systems using the available data.

My old work can answer almost questions but -

1. Your understanding is correct but TAIC would have failed to find out the Homare 23 which was equipped with the device - so called 'indirect fuel injection' as only several sets were under testing when war was over. Homare 21 had no such a device. Here is technical explanation

2. Mitsubishi had nothing to do with such an 'indirect' fuel injection system but all 'direct' like these pics of Kasei 23 from the beginning.

Mitsubishi fuel injection pump

Source: http://www.shop-online.jp/sagamihar...ody=spec&product_id=697882&category_id=100195