J.P. Instruments EDM 930 Primary Pilots Guide User Manual

Page 14

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For Your Safe Flight

Page 9

Typical Normal Measurements

The following chart lists typical normal measurement values that you
will observe for most general aircraft engines. Your particular engine’s
ranges may not fall within these values.

Measurement

Normal range

Comments

EGTs in Cruise

1350°F

1550°F

 under 200 HP engines

 high performance engines

 (EGT should drop 200°F when

full throttle is applied)

EGT span (DIF)

70 to 90°F

120 to 150°F

 fuel injected engines

 carbureted engines

TIT

1600°F average

 100° higher than EGT

CHTs

350°F (OAT 60°F)

410°F

 normally aspirated engines

 Turbocharged engines

CHT span

50 to 70°F

 100° with gasket probes

OIL T

200°F

 oil cooler thermostat typically

opens at 180°F

OIL P

30 to 60 psi

 varies with aircraft type

FUEL P (injected)

14 to 18 psi

FUEL P (carbureted)

0.5 to 8 psi

 varies with aircraft type

Shock cooling*

-40°/minute
-55°/minute

-200°/minute

 tightly cowled engines

 Bonanza

 helicopter

* Maintain a cooling rate magnitude of less than -50°/minute. You will find

that the cylinder with the greatest shock cooling may shift from front
cylinders (during climb out) to the rear cylinders (during descent ).

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