HA-109

[mad_max]

Does anyone know if the HA-109 used MW or ADI for cooling of the charge at higher powers other than cruise power like the HA-45? Both of those motors look quite compact and since the 45 had to use it because of cylinder temps; I'm wondering if the 109 also needed to use it.

I found a Ki-44 manual, but I don't read Japanese. This manual appears to be a manual on the airframe, since I see nothing that appears to be engine related. I'm at work now and will attach the manual later today.

 

[Algernon]

From the table in post 20 (thank you, Mr. Shinpachi):
Data Base: Japanese Aircraft Engines
https://ww2aircraft.net/forum/attachments/3-e-jpg.402085/

Max. boost pressure is only +300 mm Hg (1060 mm Hg or 1413 milibar absolute pressure, +5.8 psi boost pressure, 41.73 in Hg manifold pressure). It's the same, as in engine Ha-115 (Sakae 21).

From this I believe, that even with this engine water injection was not used. Fuel octane number is was sufficient.

 

[mad_max]

I've come to the same conclusion, since in that time frame their fuel was still good.

 

[Bretoal2]

From the table in post 20 (thank you, Mr. Shinpachi):
Data Base: Japanese Aircraft Engines
https://ww2aircraft.net/forum/attachments/3-e-jpg.402085/

Max. boost pressure is only +300 mm Hg (1060 mm Hg or 1413 milibar absolute pressure, +5.8 psi boost pressure, 41.73 in Hg manifold pressure). It's the same, as in engine Ha-115 (Sakae 21).

From this I believe, that even with this engine water injection was not used. Fuel octane number is was sufficient.

I bet in these japanese figures the "boost" values are WATER mm.

So +300 mm H²O = 1,3 ata = 988 mm Hg = 38,9 in Hg....

See that for "Ha 217 special", max boost value is + 650. Would it be in mm Hg, that would mean +1410 mm Hg total pressure, i.e. +1,85 ata or 55,5 in Hg. Hard to believe in such a "big" engine with only a 9,00 supercharger ratio ... but with +650 mm H²O, we have +1254 mm Hg, +1,65 ata or +49,3 in Hg, that are more common values.

 

[Shinpachi]

When the Ha-45 was in sevice, there was no need to improve the Ha-109 anymore.
Manifold pressure was measured by the mercury column values for mm Hg or kilo-grams per square centimeter.