Aircraft investigation info>>>>>>> HOME PAGE

performance calculations for the Pratt & Whitney R-1340-C1 Wasp aircraft engine

Pratt & Whitney R-1340 Wasp

Pratt & Whitney R-1340-C1 Wasp air-cooled 9 -cylinder radial engine 420 [hp](313.2 KW)

introduction : August 1928 country : United States importance : ****

applications : Ford 5-AT

normal rating : 420 [hp](313.2 KW) at 2000 [rpm] at sea level

no reduction, direct drive, valvetrain : SOHC

fuel system : oil system :

weight engine(s) dry : 340.0 [kg] = 1.09 [kg/KW]

bore : 146.0 [mm] stroke : 146.0 [mm]

valve inlet area : 32.5 [cm^2] one inlet and one exhaust valve in cylinder head

gasspeed at inlet valve : 35.3 [m/s]

throttle : 91 /100 open, mixture :13.0 :1

compression ratio : 5.25 : 1

stroke volume (displacement): 22.020 [litre]

compression volume (Vc): 4.400 [litre]

total volume (Vt): 26.398 [litre]

diam. engine : 111 [cm]

engine length: 0.29 [m]

specific power : 14.2 [kW/litre]

torque : 1495 [Nm]

engine weight/volume : 15.4 : [kg/litre]

average piston speed (Cm): 9.7 [m/s]

***************************************************************************

intake pressure at 500 [m] altitude Pi : 0.95 [kg/cm2]

Aviation Powerplants - A Warbirds Resource Group Site

mean engine pressure (M.E.P.) at 500 [m] altitude Pm : 7.03 [kg/cm2]

compression pressure at 500 [m] altitude Pc: 8.92 [kg/cm2]

estimated combustion pressure at 500 [m] Pe : 35.64 [kg/cm2]

exhaust pressure at 500 [m] Pu : 3.73 [kg/cm^2 ]

**************************************************************************

compression-start temperature at 500 [m] Tic: 353 [°K] (80 [°C])

compression-end temperature at 500 [m] Tc: 540 [°K] (267 [°C])

average engine wall temperature at 500 [m] : 476 [K] (202 [°C])

caloric combustion temperature at 500 [m] Tec: 2207 [°K] (1934 [°C])

polytroph combustion temperature at 500 [m] Tep : 2159 [°K] (1886 [°C])

estimated combustion temperature at 500 [m] Te (T4): 2152 [°K] (1879 [°C])

polytrope expansion-end temperature at 500 [m] Tup: 1148 [°K] (875 [°C])

exhaust stroke end temperature at 500 [m] Tu: 1091 [°K] (818 [°C])

*********************************************************************************

calculations for take-off/emergency power at sea level

intake pressure at sea level Pi : 0.95 [kg/cm2]

compression-end temperature at sealevel max rpm Tc:554 [°K] (281 [°C])

polytrope combustion temperature at sea level Tec: 2214 [°K] (1941 [°C])

caloric combustion temperature at sea level Tec: 2283 [°K] (2010 [°C])

emergency/take off rating at 2176 [rpm] at sea level : 450 [hp]

Thermal efficiency Nth : 0.361 [ ]

Mechanical efficiency Nm : 0.765 [ ]

Thermo-dynamic efficiency Ntd : 0.276 [ ]

design hours : 1360 [hr] time between overhaul : 39 [hr]

dispersed engine heat by cooling air : 5650.02 [Kcal/minuut/m2]

required cooling surface : 16.67 [m2]

weight cooling ribs : 183.77 [kg]

fuel consumption optimum mixture at 2000.00 [rpm] at 500 [m]: 93.52 [kg/hr]

specific fuel consumption thermo-dynamic : 217 [gr/epk] = 292 [gr/kwh]

estimated specific fuel consumption (cruise power) at 500 [m] optimum mixture : 320 [gr/kwh]

estimated sfc (cruise power) at 2750 [m] rich mixture : 324 [gr/kwh]

specific fuel consumption at 500 [m] at 2000 [rpm] with mixture :13.0 :1 : 299 [gr/kwh]

intake pressure at 500 [m] altitude Pi : 0.95 [kg/cm2] > om te verhogen vulling verhogen line 4063

estimated specific oil consumption (cruise power) : 16 [gr/kwh]

Literature :

Pratt & Whitney R-1340 Wasp - Wikipedia

Handbook of aeronautics volume II aero-engines page 9

DISCLAIMER Above calculations are based on published data, they must be

regarded as indication not as facts.

Calculated performance and weight may not correspond with actual weights

and performances and are assumptions for which no responsibility can be taken.

Calculations are as accurate as possible, they can be fine-tuned when more data

is available, you are welcome to give suggestions and additional information

so we can improve our program. For copyright on drawings/photographs/

content please mail to below mail address

(c) B van der Zalm 10 May 2021 contact : info.aircraftinvestigation@gmail.com python 3.7.4

notes :