Turbocharged Engines
The leaning process for turbocharged engines is by reference to the first
cylinder or TIT to reach peak. However, the TIT
factory red line
may
limit the leaning process. TIT red line is generally 1650°F, and up to
1750°F in some installations. If during leaning the TIT exceeds red line by
less than 100°, the LeanFind procedure will continue to operate and the
TIT redline alarm will be suppressed for one minute, allowing you to
complete the leaning process. Otherwise the digital display will show, for
example,
1650 TIT
and
TIT
will flash. You will notice that in some
cases the TIT reads 100°F hotter than the hottest EGT. This is caused by
unburned fuel in the exhaust igniting at the turbine inlet.
The reduced size of the
JPI
Hastaloy-X-tip probes produces faster
response and more accurate than the massive factory installed probe.
Therefore
JPI
probes may read as much as 100°F higher than the
factory installed probe. However, note that the engines were certified with
the factory installed probe and gauge, and this gauge reading is the
limiting factor when adjusting your engines.
Never exceed red line on the factory installed instruments.
Operation for each Phase of Flight
Engine Run-Up
(you can add this to your run-up
checklist.)
Suggested setup:
Section 4 -
Set engine to run up RPM
Section 5 -
Normalize
view
Section 6 -
Manual mode
Verify:
uniform rise of about 50°F in all EGTs in single magneto
operation.
uniform rise of EGTs with application of the mixture control.
Be alert for:
unusually low voltage (less than nominal battery voltage)
Page 22
Engine Data Management
Summary of Contents for EDM-760 TWIN
Page 69: ...For Your Safe Flight Page 63 ...
