Nakajima Ha5

Last updated
Ha5
Type14-cylinder, air-cooled, two-row radial piston engine
National originJapan
Manufacturer Nakajima Aircraft Company
Major applications Mitsubishi Ki-21
Mitsubishi Ki-30
Mitsubishi Ki-57
Nakajima Ki-49 (Ha-41/Ha-109)

Nakajima Ki-44 (Ha-41/Ha109)

Developed into Nakajima Ha219

The Nakajima Ha5 is a twin row, 14 cylinder air-cooled radial aircraft engine built by the Japanese Nakajima Aircraft Company. The engine was a development of earlier single-row Japanese engines, the Kotobuki and Hikari, which had combined features of the Bristol Jupiter and Pratt & Whitney R-1340 Wasp designs.

Contents

First introduced in a 1,000 PS prototype in 1933, about 7,000 civilian and 5,500 military Ha-5's were built during World War II. The Ha-5 had separate cam-discs for the front and rear rows of cylinders like American designs, rather than using a single, front-mounted cam-disc with long and short pushrods to operate both rows of cylinder valves.

The Ha-5 was a twin-row development of the Nakajima Hikari, which was itself a development of the Nakajima Kotobuki. It spawned several improved variants, namely the Ha-41, with a single stage supercharger, and the Ha-109, which featured a two-speed, single stage supercharger. The later Ha-219 was based on the same cylinder design, but was increased in size to 18 cylinders.

Design and development

In 1917, Chikuhei Nakajima set up the "Airplane Institute" at Ojima Town in Gunma Prefecture. In 1918 they built their first airplane; the "Nakajima Type 1" with a U.S.A. made engine. [1] In 1920 the company sent Kimihei Nakajima to France to study European advances, and in 1922 started their own engine factory in Tokyo. This led to production of engines based on the Lawrance A-3 two-cylinder air-cooled horizontally opposed engine.

At the time the Lawrance was an oddity. Most air-cooled engines at that time were rotary engines, using cylinders that rotated together with the propeller with a fixed crankshaft, in order to improve cooling but Kimihei overheard that an engine with good cooling capability with stationary cylinders was being developed in England: a radial engine. He observed the English Gloster Gamecock fighter with its Bristol Jupiter engine, which was an advanced design for the era with an automatic adjustment device for tappet clearance, spiral intake piping for even charge air distribution, and a four-valve intake and exhaust system. He acquired a manufacturing license for the Jupiter in 1925. [2] In 1927, after inviting two production engineer instructors from the Bristol company, the Jupiter Type 6 of 420 PS and Type 7 of 450 PS with a supercharger were put into production at the Nakajima factory.

After studying the Pratt & Whitney Wasp 9-cylinder radial, Nakajima tried to combine the good points found in Jupiter design with the rational design of the Wasp. Nakajima then produced a series of engine types, named "AA", "AB", "AC", and "AD", as engineering exercises. [1] The next engine design, the "AE", was innovative, with a bore of 160 mm and a stroke of 170 mm.

Prototypes were made and performance tests were done, but this engine was not adopted due to its very complex engineering. Nakajima continued testing different cylinder designs. In 1929, the "AH" design, with bore and stroke of 146 × 160 mm and a total displacement of 24.1 L, was completed. This was to be the final version of this basic engine design. [1]

In June 1930 the first prototype of was completed and it passed the durability test for the type approval in the summer. Then flight tests were started using a Nakajima A2N carrier plane. Nakajima had successfully designed the first original Japanese air-cooled 9-cylinder engine, the 450 PS "Kotobuki", which would over time be developed into the Ha-5 and its successors. In December 1931, this engine was approved and adopted by the Navy for the Navy Type 96 Carrier fighter. The engine was named, in connection with the Jupiter engine, "Kotobuki". [1]

The "Kotobuki" engine was improved and developed into the "Hikari (light)" engine with the bore and stroke expanded to the limit of the cylinder (160 × 180 mm for a displacement of 32.6 L), with the power was increased to 720 PS. The "Hikari" was used in Type 95 carrier fighters and Type 96 Carrier Attack Plane. [1]

Nakajima knew that engines of higher power would be needed and began work on the Ha-5, a new 14-cylinder, twin-row design that was based on the 160 × 180 mm cylinder of the Hikari. The Ha-5 prototype engine was completed in 1933, producing 1,000 PS. An improved Ha-5 was developed as a 1,500 PS engine. In all about 5,500 Ha-5 engines were produced for the military. [1]

Later on, as the weights of aircraft rose and higher speeds were required, Nakajima continued to improve the Ha-5 design, creating the "Ha-41" and "Ha-109", which shared the same 146mm x 160mm bore and stroke as the Ha-5, but were increased from the 950 hp of the Ha5 to 1,260 hp and 1,440 hp, respectively. The unified code for the Ha-41 was "Ha-34". Later the engine was developed into an 18-cylinder, twin-row engine called the "Ha-219", but this never got into mass development phase before the war ended a total of 10 were built. All these engines used essentially the same cylinder heads, the differences being in supercharging systems and maximum engine revolutions per minute.

The Ha-5 and Ha-41 shared the same weight of 630 kg, while the Ha-109 weighed 720 kg due to its larger, twin-stage supercharger system. The Ha-41 was the primary engine of early variants of the Nakajima Ki-49 "Helen" bomber, and the Nakajima Ki-44 "Tojo" fighter, later versions of both planes using the more powerful Ha-109 engine. Early versions of the Mitsubishi Ki-21 "Sally" used the Ha-5. The Ha-41 would have been an ideal power plant in aircraft that used the Mitsubishi Kasei, being of smaller dimensions and displacement, yet making equivalent power levels. Nine of the Ha-219 engines where issued to the Kitai Squadron to use for the new Ki-84N. According to two surviving IJAAF mechanics in 1987, the Ki-84N had a recorded speed of 448–450 mph at a ceiling of 42,254 ft when using war emergency power. The engine required much maintenance to keep running, and it overheated when flying at low speeds. [3]

Variants

Ha5
634 kW (850 hp), Base design, (used on Mitsubishi Ki-21 Army Type 97 Heavy Bomber) [4]
Ha5-KAI
634 kW (850 hp), (used on Mitsubishi Ki-30) [5]
Ha5
660 kW (890 hp) (used on Nakajima Ki-19) [6]
Ha5-KAI
708 kW (950 hp), (used on Mitsubishi Ki-57 and Ki-57-I Army Type 100 Transport Model 1) [7]
Ha5-KAI
708 kW (950 hp) take-off, 805 kW (960 hp) at 3,000 m (11,810 ft), (used on Mitsubishi Ki-30 and on first prototype Nakajima Ki-49 Donryu) [8]
Ha5-KAI
708 kW (950 hp) take-off, 805 kW (1,080 hp) at 4,000 m (13,125 ft), (used on Mitsubishi Ki-21-I Army Type 97 Heavy Bomber Model 1 and Ki-21-Ia, Army Type 97 Heavy Bomber Model 1A) [4]
Ha41
1,260 hp at 2,500rpm takeoff, 1,260 hp at 2,450 rpm at 3,700 m
Ha109
1,500 hp at 2,650rpm takeoff, 1,440 hp at 2,600 rpm at 5,200 m
Ha219
1,895 kW (2,541 hp) ( 10 built used on Tachikawa Ki-94-2, Ki-87 and Ki-84-N late war prototypes most destroyed after war with documents.

Applications

The Ha5 engine was used to power:

The Ha41 engine was used to power:

The Ha109 engine was used to power:

Specifications (Nakajima Ha-5)

Data from Engine development at Nakajima 1923–1945, Engine History of Nakajima Aircraft. [9]

General characteristics

Components

Performance

See also

Related development

Comparable engines

Related lists

Related Research Articles

<span class="mw-page-title-main">Mitsubishi Ki-46</span> Type of aircraft

The Mitsubishi Ki-46 was a twin-engine reconnaissance aircraft used by the Imperial Japanese Army in World War II. Its Army Shiki designation was Type 100 Command Reconnaissance Aircraft (一〇〇式司令部偵察機); the Allied brevity code name was "Dinah".

<span class="mw-page-title-main">Nakajima Homare</span> 1940s Japanese piston aircraft engine

The Nakajima Homare was an air-cooled twin-row 18 cylinder radial Japanese aircraft engine manufactured during World War II. Producing almost 2,000 horsepower, it was used widely by both the Imperial Japanese Army and the Imperial Japanese Navy. Given the Navy service designation NK9, the "Homare" was also given the company designation NBA, Army experimental designation Ha-45 (ハ45) or, Army long designation Nakajima Army Type 4 1,900 hp Air-Cooled Radial and, (coincidentally) unified designation code of Ha-45.

<span class="mw-page-title-main">Mitsubishi Kasei</span> 1930s Japanese piston aircraft engine

The Mitsubishi Kasei was a two-row, 14-cylinder air-cooled radial engine built by Mitsubishi Heavy Industries and used in a variety of World War II Japanese aircraft, such as Mitsubishi J2M and Mitsubishi G4M. The Mitsubishi model designation for this engine was A10 while it was an experimental project, in service it was known as the MK4, and known as the Ha101 & Ha111 by the Army and Kasei by the Navy. According to unified designation code it was Ha-32 of the variants from 11 to 27.

<span class="mw-page-title-main">Nakajima Sakae</span> 1940s Japanese piston aircraft engine

The Nakajima Sakae was a two-row, 14-cylinder air-cooled radial engine used in a number of combat aircraft of the Imperial Japanese Navy and Imperial Japanese Army before and during World War II.

<span class="mw-page-title-main">Yokosuka B4Y</span> Japanese carrier-borne torpedo bomber

The Yokosuka B4Y,, carrier-borne torpedo bomber was used by the Imperial Japanese Navy Air Service from 1936 to 1943. The B4Y replaced the Mitsubishi B2M2 and was the last biplane bomber used operationally by the Imperial Japanese Navy. The Allied reporting name was "Jean".

<span class="mw-page-title-main">Nakajima Ki-49</span> Type of aircraft

The Nakajima Ki-49Donryu was a twin-engine Japanese World War II heavy bomber. It was designed to carry out daylight bombing missions, without the protection of escort fighters. Consequently, while its official designation, Army Type 100 Heavy Bomber, was accurate in regard to its formidable defensive armament and armor, these features restricted the Ki-49 to payloads comparable to those of lighter medium bombers – the initial production variant could carry only 1,000 kg (2,200 lb) of bombs.

The Nakajima Ha1 Kotobuki was an aero-engine developed by Nakajima. It was a radial piston developed under licence from the Bristol Jupiter.

<span class="mw-page-title-main">Nakajima Ki-34</span> Japanese military transport aircraft

The Nakajima Ki-34 was a Japanese light transport of World War II. It was a twin-engine, low-wing monoplane; the undercarriage was of tailwheel type with retractable main units. During the Pacific War, the Allies assigned the type the reporting name Thora.

The Nakajima Hikari was a nine-cylinder, air-cooled, radial aircraft engine developed in Japan for Navy use during World War II by the Nakajima Aircraft Company. It was a development of the Nakajima Kotobuki and Wright Cyclone. In Army use it was known as the Ha20.

The Mitsubishi Kinsei was a 14-cylinder, air-cooled, twin-row radial aircraft engine developed by Mitsubishi Heavy Industries in Japan in 1934 for the Imperial Japanese Navy. The Mitsubishi model designation for this engine was A8 while it was an experimental project; in service, it was known as the MK8 "Kinsei" by the Navy. In 1941 the engine was adopted by Army, receiving designation Ha-112. In May 1943 it received Ha-33 unified designation code.

<span class="mw-page-title-main">Aichi Atsuta</span>

The Aichi AE1A Atsuta was a Japanese licensed version of the German Daimler-Benz DB 601A 12-cylinder liquid-cooled inverted-vee aircraft engine. The Atsuta powered only two models of Imperial Japanese Navy Air Service (IJNAS) aircraft in World War II. The Imperial Japanese Army Air Service (IJAAS) used the same engine to power its Kawasaki Ki-61 Hien fighter. The IJNAS's Atsuta and its IJAAS cousin, the Ha-40 were based on the engine that powered Germany's Messerschmitt Bf 109E fighter.

<span class="mw-page-title-main">Mitsubishi Ki-2</span> Type of aircraft

The Mitsubishi Ki-2 was a light bomber built by Mitsubishi for the Imperial Japanese Army Air Service (IJAAS) in the 1930s. Its Allied nickname was "Louise". Despite its antiquated appearance, the Ki-2 was successfully used in Manchukuo and in North China during the early stages of the Second Sino-Japanese War, in areas where danger from enemy fighter aircraft was minimal. It was later used in a training role.

<span class="mw-page-title-main">Mitsubishi K3M</span> Japanese trainer aircraft

The Mitsubishi K3M was a trainer built by Mitsubishi which was used by the Imperial Japanese Navy in an extremely wide variety of roles, including light transport, liaison aircraft, utility aircraft and occasionally light bomber. Its Allied reporting name was Pine.

<span class="mw-page-title-main">Mitsubishi Ki-18</span> Japanese fighter prototype

The Mitsubishi Ki-18 was an unsuccessful and unsolicited attempt by Mitsubishi to meet a 1934 requirement issued by the Japanese Army for a modern single-seat monoplane fighter suitable to the needs of the Imperial Japanese Army Air Force. During this competition, Nakajima entered the Nakajima Ki-11, and Kawasaki entered the more maneuverable Kawasaki Ki-10 biplane. The competition was won by Kawasaki, but the new fighter was not accepted by the IJAAF with much enthusiasm.

<span class="mw-page-title-main">Kawasaki Ha40</span>

The Kawasaki Ha40, also known as the Army Type 2 1,100 hp Liquid Cooled In-line and Ha-60, was a license-built Daimler-Benz DB 601Aa 12-cylinder liquid-cooled inverted-vee aircraft engine. The Imperial Japanese Army Air Service (IJAAS) selected the engine to power its Kawasaki Ki-61 fighter.

<span class="mw-page-title-main">Nakajima Mamoru</span> 1940s Japanese piston aircraft engine

The Nakajima Mamoru engine was a 14-cylinder, air-cooled, two-row radial engine of 1870 hp. At some 44.9 litres displacement, it was one of the largest-displacement 14-cylinder radial engines in the world, rivalling the similar configuration Allies' American Wright Twin Cyclone engine of 42.7 litre and Soviet Shvetsov ASh-82 engine of 41.2 litre displacement levels, and was meant to compete with early 18-cyl engines. The Nakajima model designation for this engine was NAK while it was an experimental project, in service it was known as the NK7, and known as the Ha-103 by the Army and "Mamori" or "Mamoru" by the Navy. According to unified designation code it was Ha-36. The meanings of these two Japanese words are very similar, Mamori translates as protection and Mamoru, translates as to guard, protect, defend and obey.

The Mitsubishi Shinten was a two-row, 14-cylinder air-cooled radial engine built by the Mitsubishi Aircraft Company for the Imperial Japanese Army Air Service (IJAAS) and the Imperial Japanese Navy Air Service (IJNAS) in the early 1930s. Like many aircraft engines in Japan, there were multiple designations for this engine. The company model designation was A6(7) while it was an experimental engine project. Once accepted, it was known as the "Shinten" or MK1 by the IJNAS, and Ha6 by the IJAAS.

The Mitsubishi Zuisei was a 14-cylinder, supercharged, air-cooled, two-row radial engine used in a variety of early World War II Japanese aircraft. It was one of the smallest 14-cyl. engines in the world and the smallest diameter Japanese engine. The Mitsubishi model designation for this engine was A14 while it was an experimental project, in service it was known as the MK2, followed by the revision code letter, and known as the Ha26 & Ha102 by the Army and "Zuisei" by the Navy. Unified designation code was [Ha-31].

The Piaggio P.XIX was an Italian aircraft engine produced by Rinaldo Piaggio S.p.A. during World War II and used to power aircraft of the Regia Aeronautica.

The Mitsubishi Ha-43, known as the Ha-211 by the Imperial Japanese Army Air Force (IJAAF) and MK9 by the Imperial Japanese Navy Air Service (IJNAS)), was a Japanese 18-cylinder, twin-row air-cooled radial engine developed during World War II. It was a more powerful derivative of Mitsubishi's 14-cylinder Kinsei. While planned for use in several promising aircraft, only prototypes were made and the engine never saw combat.

References

Notes

  1. 1 2 3 4 5 6 Engine development at Nakajima 1923–1945
  2. Gunston 1989, p.104.
  3. 1987 JTVD documentary: The Last Men
  4. 1 2 Francillon pg 162
  5. Francillon pg 167
  6. Mikesh & Abe pg 221
  7. Francillon pg 184
  8. Francillon pg 228
  9. Engine History of Nakajima Aircraft ISBN   4-87357-007-7

Bibliography