I read quite a bit of argument about the Nakajima Ha-45-21 Homare of the N1K2-J and Ki-84. This should pour a bit more lighter fluid on the discussion. If you compare the output of the Pratt-Whitney R-2180 E series engines to the Homare you can get a reasonable comparison. First the data;
The P&W R-2180E is exactly 2181 cu in. Bore and stroke of 146 by 152.5mm. The same cylinders as the R-2800 but in 14 cylinders. Max RPM is 2800 and MAP is 54”.
The BHP performance figures are:
Take off
1650 SL
1800 ADI
WEP (ADI)
1800 to 2700'
1550 to 13Kft
MIL
1650 to 3000’
1300 to 16Kft
Normal
1400 to 6000’
1250 to 15.5Kft
Max Cruise
1300 to 8000’
1150 to 17.5K
The Nakajima Ha-45-21 (NK9H) Homare 21 is exactly 2186 cu in. Bore and stroke are 130 by 150mm. The same cylinder as the Nakajima SAKAE 21 but in 18 cylinders. The max RPM is 3000 and the MAP is unconfirmed.
The BHP performance figures are;
Take off
1670 SL
1830 to
1970 ADI
WEP (ADI)
1830 to 5700'
1610 to 16Kft
MIL
1655 to 9300’
1360 to 20Kft
Normal
1400 to 12Kft
1250 to 18.5Kft
Max Cruise
1200 to 15Kft
1100 to 21Kft
Remember the RPM are faster and probably the fuel is 115/130 octane. Also the supercharger is made for a fighter application whereas the R-2180 is made for the SAAB 90A airliner.
As a comparison of an engine which normally runs on “Hi-Test” is the R-2800-B series is rated at 2100-54in (2400-56in ADI) takeoff and 1800-45in SL max continuous. With 91 grade fuel the take off is reduced to 1650-42in (no ADI) and 1380-38.5in SL max continuous.
So there is my two cents into the ring….so cry havoc and loose the dogs of war!!!
[This message has been edited by kreighund (edited 03-17-2001).]
[This message has been edited by kreighund (edited 03-17-2001).]
[This message has been edited by kreighund (edited 03-17-2001).]
