http://www.fighter-planes.com/info/a6m.htmA6M8
The A6M8 was the last production version of the Reisen. Bomb damage to the Nakajima engine plants (as well as Nakajima's decision to decrease Sakae production in preparation for the production of the 18-cylinder Homare radial) had resulted in a shortage of the Sakae radial engines which had previously powered the Zero Fighter. Consequently, the Navy finally accepted Mitsubishi's proposal to use their more powerful MK8K Kinsei 62 (Ha-33/62) fourteen-cylinder air-cooled radial engine.
Manufacture of the Kinsei-powered A6M8 prototypes was finally approved in November 1944. The forward fuselage was completely redesigned to accommodate the 1560 hp Mitsubishi MK8P Kinsei 62, which had a larger diameter than the Sakae, requiring that the fuselage-mounted gun be removed. At the same time, the fuel tank fire-extinguishing system was improved, and additional fuel tankage was added. The fuselage centerline could carry a single 1100-lb bomb, and a pair of 77-Imp gall drop tanks could be carried underneath the wings.
The first A6M8 was completed in April of 1945. Flight tests turned up a number of faults in the fuel and oil systems, plus a tendency to overheat, and the machine had to be returned to the factory for these to be corrected. By enlarging the oil tank, revising the pipe lines, and by fitting engine cooling baffles, these snags were eliminated. At high altitudes, the tendency for the fuel pressure to drop was overcome by altering the fuel regulating valve.
After completion of service trials at Aomori, on May 25, 1945 the A6M8 was approved for manufacture as the Navy Type 0 Carrier Fighter Model 64. A second prototype was accepted in June, and both were turned over to the Yokosuka Experimental Air Corps Proving Division throughout July.
Production of the A6M8 was assigned to dispersed Mitsubishi and Nakajima factories, with as many as 6300 machines being ordered. However, owing to the chaotic conditions prevailing in Japanese industry in the closing months of the war, none were actually delivered.
Specification of A6M8 Navy Type 0 Carrier Fighter Model 64:
One Mitsubishi MK8P Kinsei 62 fourteen cylinder air-cooled radial, rated at 1560 hp for takeoff, 1340 hp at 6890 feet, 1180 hp at 19,030 feet.
Performance: Maximum speed 356 mph at 19,685 feet. Climb to 16.685 feet in 6 minutes 50 seconds. Service ceiling 37,075 feet. Dimensions: Wingspan 36 feet 1 1/16 inches, length 30 feet 3 21/32 inches, height 11 feet 11 7/32 inches, wing area 229.27 square feet. Weights: 4740 pounds empty, 6945 pounds loaded.
Armament: Two 13.2-mm Type 3 machine guns and two 20-mm Type 99 cannon in the wings. A single 1100-lb bomb could be carried underneath the fuselage centerline. An additional two 132-lb bombs could be carried underneath the wings.
Text : Joe Baugher
