R-1820-G5 Cyclones MAP at 1000hp/2200rpm -setting.

[Wmaker]

Hi,

Does anyone know the manifold pressure at the Emergency power rating (1000hp/2200rpm)? For example Curtiss CW-21 Demons were powered by the R-1820-G5 Cyclone if someone has specification document for that plane. Brewster Aeronautical Corporation's Specification for Brewster Model 239 for example doesn't mention it.

[morfiend]

http://rgl.faa.gov/Regulatory_and_Guidance_library/rgMakeModel.nsf/0/14f1fb9c650f34d78525676a006354ef/$FILE/ATTNWJTA/5E-10.pdf


 not sure if this helps but!!!

[Widewing]

http://rgl.faa.gov/Regulatory_and_Guidance_library/rgMakeModel.nsf/0/14f1fb9c650f34d78525676a006354ef/$FILE/ATTNWJTA/5E-10.pdf


 not sure if this helps but!!!

It should help as the R-1820-G5 is the commercial version of the R-1820-40.


My regards,

Widewing

[morfiend]

 

[Casca]

I used to fly behind a -97 mounted on a Bull Thrush.  It had 5 minute takeoff power of an alleged 1200 hp at 45" and 2500 rpm sea level standard and a METO of 1100 hp at 43" and 2400.  Of course in a light airplane like the Thrush you never needed to approach those settings even when fully loaded.  Not sure how that would relate to War Emergency Power.  God I hated that engine.

[Wmaker]

It should help as the R-1820-G5 is the commercial version of the R-1820-40.

Well, R-1820-40 is a heavier 1200hp version which powered the F2A-2, so I don't think that the power settings are identical. According to the table which morfiend posted (Thanks morfiend ) R-1820-40 runs at higher RPM but lower MAP than G5 when it puts out 1000hp. This I know from the fact that G5 puts out 950hp at 41" which is already higher than the MAP for the R-1820-40 at 1000hp which is 39.5" accourding to that table. From the table morfiend posted I couldn't find power/rpm- combo which matches G5's War Emergency Rating (2200rpm/1000hp) on any of the Cyclone 9 variants listed in it.

So the MAP at 1000hp probably around 45" or so, would be nice to get the exact figure.

[Wmaker]

This I know from the fact that G5 puts out 950hp at 41"

The Pilot's Handbook for Brewster Model 239 actually says 39.5" for the 950hp at sea level. The power setting 104cmHg mentioned as what Finns used for take-off setting (which should put out 950hp) in a Finnish "Pilot's View Point II-book" the translates into that 41". I just converted the cmHg units without looking at the pilot's hand book assuming they would be the same.

Hmm...

[morfiend]

I did a fair amount of seaching on this,not sure why but did....

 I found plenty of G5 references and many were either finnish or russian,which I couldnt understand.Although I did notice the MAP seemed to be airframe dependant.

 Good luck with your quest.