Pratt & Whitney R-1830 performance chart

[Juha]

Hello Franek
It seems that Peter will deliver just what you want, but here some info from “Detail specifications for Curtiss Hawk 75-A Airplane” from Curtiss.
P&W Twin Wasp S3C3-G geared
Horsepower max. at critical rammed alt. 950
Horsepower at takeoff (2700 rpm) 1100
Horsepower max at cruising (2200 rpm) 700
Horsepower max at sea level (2700 rpm) 950
Compression ratio__________________6.7:1
Blower Ratio______________________8.0:1
Propeller Gear Ratio________________16:9
Propeller Diameter (Curtiss 3 Blade) 10’-1½”

For H-75A with this engine critical altitude was 4650m.

Juha