Successor to the Zero

[Hardrada55]

The Japanese issued the specifications for the A6M "Zero" about the same time as the introduction into service of the Mitsubishi A5M "Claude".  Have the original 1941 16-Shi Japanese Navy specifications for the successor to Mitsubishi's A6M "Zero" fighter ever surfaced?

As I understand it, there was a delay in starting design work on the 16-Shi design for a successor to the new A6M Reisen in 1940 and 1941 because of problems with development of the 14-Shi Mitsubishi J2M land based interceptor "Raiden" and the illness of chief designer Jiro Horikoshi.  By the time Mitsubishi was able to return work on the successor to the Zero, it was April of 1942 and the specifications had been updated to the 17-Shi version.  The 17-Shi specifications resulted in the Mitsubishi A7M "Sam" carrier fighter.   

What if...Jiro Horikoshi scraped the 1939 14 Shi specification for the Mitsubishi J2M land based interceptor and didn't get sick and instead began design in 1940-1941 of a successor to the A6M "Zero" using the 2,572cubic inch, MK4 Mitsubishi Kasei engine rated at 1,530 hp for take-off, 1,400 hp at 2,600 m and 1,280 hp at 6,000 m, driving three-blade metal propellers?   Eventually the Kasei would give 1,825 hp for take-off, 1,680 hp at 2,100 m and 1,540 hp at 5,500 m.  What kind of carrier fighter plane could the Japanese have had in 1943-1944 if they pushed for a successor to the A6M "Zero" from the summer of 1940 (which was when A6M was introduced into service)? 

Of course, I am positing something bigger than a Zero with a Kasei engine, but smaller than the historical Mitsubishi A7M built to the 17-Shi specifications and delayed because of a switch from the Homare engine to a 18 cylinder approximately 2500ci Mitsubishi MK9 engine.
   

[sequoiaranger]

Sorry, but the Zero successor was the Kawanishi A7K "Jinpu-Kai", a development of the Shiden-Kai, when Mitsubishi couldn't supply a suitable successor in time.    Central part is pure Shiden-Kai. Longer tail, wing extensions (folding) and heftier engine (from a "Rita") puts the Jinpu-Kai aboard Japanese carriers as the premier carrier-borne fighter in the Pacific (until the Bearcat comes out!).


Here with wings folded up:


But seriously, perhaps the "Reppu" might have come about earlier, perhaps in a slightly smaller version. After all,  the "Reppu" was a rather large aircraft for a fighter!

PS--wecome to the What-if Board!

[Hardrada55]

I always thought the Jinpu-Kai was a seriously awesome looking airplane.  Thanks for showing us that one again.