Mysterious Japanese Engine (PIC)

[msxyz]

While scouting the web for info on the Nakajima Ha-5/41/109 engines (see other thread and help! ), I stubled on this picture that left me a bit perplexed.
This engine is at the Pima Air Museum. It's being recognized as of Japanese origin; sign says: "Nakajima Homare NK9K-S (Homare 22)"

Look at the picture:

A picture of worse quality can be seen also on the museum site: Pima Air Museum - Nakajima Homare 22

What's wrong you say? I doesn't look like a Homare at all! This is how a Nakajima Homare looks:

Note the different pushrods layout. Nakajima engines usually employed two separate radial cams for driving the valves of the front and the rear cylinder banks. Mitsubishi engines, on the other side, tended to use only one at the front. The mystery engine also has an integral cooling fan in the nose, something that I cannot quite place on any Japanese aircraft using the Homare engine.

Could the museum curators possibly make such a mistake? Is the 18 cylinder engine instead a Mitusbishi Ha-104 (Army Type 4) used on a Ki-67 bomber?

 

[Shinpachi]

At a glance, it looks Kasei for Raiden(Jack).

 

[msxyz]

At a glance, it looks Kasei for Raiden(Jack).

But this is a 18 cylinders radial. Kasei had only 14 cylinders; right?

Here are some Kasei pictures for comparison NASM Research 2

Quite close in appearance but not the same. What other Japanese planes employed a cooling fan, excluding the J2M, and used a 18 cylinder radial to begin with?

 

[Shinpachi]

Sorry, I didn't see its 18 cylinders.
That engine is possibly Mitsubishi A18A for the Ha-104 as you guessed.

 

[msxyz]

Thank you Shinpachi, it's odd to see a museum make such a mistake. These boards host a few people with connections with museums and organizations prserving historical aircrafts. I wonder if I can bring this to the attention of someone. I'm relatively new around here.

 

[Shinpachi]

Hello msxyz.

Could you check how the engine came from?
Also, where was or is the airframe.
I believe you have done a historic discovery.

 

[msxyz]

Short of contacting the museum staff, I don't have any info about it. I've never been at the Pima Air Musum (I'm on the other side of the Atlantic ocean ), I just happened to stumble on that pic and noticed that I doesn't look like all the other Homare I've seen.

Note that the museum says it's a "NK9K-S", thus it should be one of the latest models developed by Nakajima. Shinpachi, could you please check in the book "Homare, engine of tragedy" (I saw that you posted some info about it in the pinned thread) if there are photos or specific info about this subtype? I doubt in 1945 Nakajima engineers had time and resources to rework the crankcase and valve distribution mechanism but it would be one more confirmation before calling this photo a historic discovery

 

[Shinpachi]

That is never Homare like Toyota is never Nissan.

The NK9K-S which the museum claims was navy Homare model 24 or army Ha45-24.
That was a fuel injection variant of Homare model 22.
Homare model 22 was a variant of model 21 with the different gear ratio.

 

[Snautzer01]

perhaps from the collection of captured airplanes on Freeman army airfield ? see Freeman Army Air Field See Japanese aircraft.

 

[Shinpachi]

There seem more historic discoveries.

 

[Shinpachi]

This is Nakajima NK1C for navy Sakae 12 or army Ha 25.

 

[msxyz]

There seem more historic discoveries.

Even assuming it's of Japanese origin (at this point I doubt they can even recognize the nationality!), it looks more like a Kinsei or Zuisei, certainly not a Sakae.

Maybe I should open an account at J-Aircraft and rally a few die-hard historians there against the Pima Air Museum!

PS: Btw, nicely restored Sakae, there, in the second pic. It looks like it can almost spring back to life any moment!

 

[Shinpachi]

PIMA's Nakajima NK1C looks Mitsubishi Kasei model 22 but I must know its exact diameter before saying more clearly.
Diameter:
Kasei 1,340mm
Kinsei 1,218mm
Zuisei 1,118mm

I am wishing your good luck at J-aircraft, msxyz.

Also, Thanks for such a nice information about the Japanese aircraft wrecks, Snautzer01.
That place looks a treasure field.

 

[msxyz]

I am wishing your good luck at J-aircraft, msxyz.

That sounds... a bit menacing! Are the people at J-Aircraft so unfriendly towards newcomers?

About the second picture, It's difficult to judge the dimensions without something of known size nearby in the same picture. I'm ruling out the Zuisei because it's cylinders look a bit stubbier.

 

[Shinpachi]

If that is Zuisei, another historic discovery as fewer remained.

 

[Bretoal]

It seems that first and third pics show engines obviously from Gnôme-Rhone 14K ancestry...