J.P. Instruments EDM-960

For Your Safe Flight Page | 8
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 Typical Range Comments
EGTs in Cruise
1350°F
under 200 HP engines
1550°F
high performance engines
(Note: EGT should drop
200°F when full throttle is
applied)
EGT span (DIF)
70 to 90°F
fuel injected engines
120 to 150°F
carbureted engines
TIT
1600°F average
CHT
350°F (OAT 60°F)
normally aspirated engines
410°F
turbocharged engines
CHT Span
50 to 70°F
100° with gasket probes
Oil T
200°F
oil cooler thermostat opens at
180°F
OIL P
30 to 60 psi
varies with aircraft type
FUEL P (injected)
14 to 18 psi
varies with aircraft type
FUEL P
(carbureted)
0.5 to 8 psi
varies with aircraft type
Shock cooling*
-40°/minute
tightly cowled engines
-55°/minute
Bonanza
-200°/minute
helicopter
* Maintain a cooling rate magnitude of less than -50°/minute. You will find
that the cylinder with the greatest shock cooling will shift from front
cylinders (during climb out) to the rear cylinders (during descent ).