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Japanese Engine Research
at the
Smithsonian National Air and Space Museum
Page 2
Tentative Identification: Army Type 98
450Hp Radial (Army Ha13 "Ko")
A19731553000
This engine is a member of the Amakaze 20 series family of engines. Its Navy
specification counterpart would be Amakaze 23. While this engine has a heavy
preservative coating on it that doesn't make for “pretty” photographs, its
similarities to A19670090000 are apparent. The differences stand out too. The
adapted constant speed prop system in not there; it has a simple two speed prop
control. Pushrod tube design is a little different and the ignition harness is
installed on the aft side of the cylinders.
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Army Type 98
Accessory Case |
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Army Type 98
Cylinder |
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Army Type 98
Cylinder Head |
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Army Type 98
Nose Case |
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NOTE: The “Tentative” identification status is only a reflection of its lack of
a data plate. The engine accessories and construction details match the
information listed in the Army manual for the Army Type 98 450hp engine. The
missing data plate may have been “souvenired” prior to its arrival at NASM or
may have been removed by Technical Intelligence unit personnel at the time of
its capture. Tech Intel units gathered data plates throughout the war with the
goal of identifying possible targets for production sites. Large serial number
ranges reflected large factory outputs, and therefore large potential targets
for U.S. bombers. I have seen copies of leaflets distributed to Allied troops
that warn against “souveniring” in the combat zone, so this information could be
collected by Tech Intel teams. Personally, I am still holding out hope that
somewhere, in some government warehouse, that there is a large crate full of
Japanese data plates! It could answer a lot of my questions!
Ha31-21
(Zuisei 21, Army Type
1 1,050 hp Radial, Army Ha 102)
A19600334004
Right engine for NASM's Ki 45 Kai Hei "Toryu" (Dragon Killer)
Allied code name: "Nick"
Displacement is 28.0 l, two speed supercharger, 1.118 m diameter and 565 kg dry
weight.
Sources say 7,852 Zuisei 21s were built for both the Army and Navy. (This should
be considered an approximate number and has yet to be confirmed)
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Ha 31-21
Top View |
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Ha 31-21
Top View |
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Ha 31-21
Top View |
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Ha 31-21
Lower Left |
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Ha 31-21
Lower Right |
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Ha 31-21
Lower Left |
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Ha 31-21
Cylinder |
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Ha 31-21
Cylinder Head |
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Ha 31-21
Cylinder Head |
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Ha 31-21
Identification |
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Ha 31-21
Carburetor Data Plate |
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Ha 31-21
Carburetor Ducts |
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Ha 31-21
Carb Air Ducts in Cowl |
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I wish they were all this easy. Identified by stampings in the nose case and
confirmed by the carburetor data plate. It is confirmed as the right engine
because it is fitted with a hydraulic pump; the left engine is fitted with a
vacuum pump. (Nick installation)
Note the use of ejector stacks instead of an exhaust collector ring as in
earlier Zuisei 21s.
Ha32-21
Mitsubishi Kasei Model 21 (MK4P)
A19710048000
Displacement: 42.1 Liters
Bore: 150mm, Stroke: 170mm
1,850Hp (Metric) @ Takeoff
1,680Hp (Metric) @ 2,100m Low blower rated with Anti-Detonation (water)
Injection (ADI)
1,570Hp (Metric) @ 5,500m Rated high blower with ADI
Double planetary spur reduction gear, Ratio: 0.538
Dry weight: 780kg
Diameter: 1.340m
Available in about 18 different models, the Kasei was one of Japan's most
produced engines.
Approximately 9,323 Kasei Model 20 engines were built during the war.
The Model 21 powered the Mitsubishi G4M2-22 Navy Type 1 Attack Bomber (Allied
code name: "Betty 22") and others.
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Ha32-21
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Ha32-21
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Ha32-21
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Ha32-21
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Ha32-21
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Ha32-21
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Ha32-21
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Ha32-22
Mitsubishi Kasei Model 22 (MK4Q)
A19480182000
Displacement: 42.1 Liters
Bore: 150mm, Stroke: 170mm
1,850Hp (Metric) @ Takeoff
1,680Hp (Metric) @ 2,100m Low blower rated with Anti-Detonation (water)
Injection (ADI)
1,540Hp (Metric) @ 5,500m Rated high blower with ADI
Planetary bevel reduction gear, Ratio: 0.500
Dry weight: 750kg
Diameter: 1.340m
The nose case tells the story. This is a Kasei 21 redesigned to accept a larger
diameter four-blade propeller. Specifically for the Kawanishi H8K2-12 Navy Type
2 Flying Boat (Allied code name "Emily12").
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Ha32-22
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Ha32-22
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Ha32-22
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Ha32-22
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The Kanji on the nose case reads "Kasei 22 Model".
The numbered photo points out a few details in the ADI system and the ignition
system.
#1) Points out the ADI discharge control valve. The same on all ADI equipped
Kasei's. Directly connected to the manifold pressure regulator, it controls the
flow of water/methanol mixture at boost numbers over +160 mm/hg.
#2) Manual control of ignition advance. This is a feature of all Kasei models
and allowed the pilot an adjustment of about 8-10 degrees in the ignition timing
depending on the magnetos installed. (32 degrees BTDC maximum advance on all
engines).
#3) Line connection for the ADI manifold. This is a horseshoe shaped manifold
with the open end of the shoe at the bottom. Inlet on the top as you see it and
drains on the bottom. If the engine has this fitting it is equipped with ADI.
Army
Type 1 1,050 hp Radial
(Army Ha102, Mitsubishi Zuisei 21)
A19601984000
Information is the
same as the Nick engine, but I can't say for sure what this unit was installed
in. The presence of a data plate and the early 1944 production date suggests
this engine may have been equipped with an exhaust ring. Other applications for
the Zuisei 21 were early versions of the Army Ki-46 (code name "Dinah") and the
Mitsubishi MC-20v (code name "Topsy")
Note the
identification is confirmed on the carb data plate and the minor change in float
level compared to the Nick engine.
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Ha102
Front View |
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Ha102
Cylinder Head |
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Ha102
Data Plate |
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Ha102
Accessory Section |
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Ha102
Carburetor |
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Ha102
Carburetor Data Plate |
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The accessory case photo shows a good view of carburetor detail. On top is a
manual mixture control (via float chamber vent control) and an automatic
manifold pressure regulator. The blank entry on the carb data plate under
“economizer” is due to the fact that the manifold pressure regulator performs
this function.
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