Electronics International UBG-16 - Manual (Page 15)

recommended limit. As you get to know your engine’s normal operating temperatures, you may want
to adjust these limits accordingly.
2. Selecting the Lower EGT Limits: 2. Selecting the Lower EGT Limits: 2. Selecting the Lower EGT Limits: 2. Selecting the Lower EGT Limits: 2. Selecting the Lower EGT Limits:
In normal cruise, at low altitude, adjust the mixture full rich and wait for the EGTs to stabilize. Once the
EGTs have stabilized, record the EGT readings for each cylinder. Program the Lower Limit for each
cylinder 40’F below the recorded readings for that cylinder. This is only a recommended limit. As you get
to know your engine’s normal operating temperatures, you may want to adjust these limits accordingly.
During climbs, the cylinder head temperatures will rise rapidly until the heat absorbed by the combustion walls is
dissipated through the engine’s cooling fins. At this point, the CHTs will stabilize. Any change in throttle,
mixture, cowl, OAT or airspeed will affect the CHTs and their rate of change. Since rate and trend information
can be interpreted easily on the UBG digital display, changing any one of these parameters to stabilize, slow or
reduce the CHT is possible with almost immediate results.
Cylinder head temperatures are related to your engine’s ability to produce power. If any cylinder has a problem
producing power (fouled plug, burned or stuck valve, broken ring, intake leak, plugged injector, timing problem,
bad mag, etc.) the cylinder head temperature for that cylinder may or may not be abnormally high or low, depend-
ing on the extent of the problem. Generally, we have not found cylinder head temperatures to be a good tool for
detecting problems. However, CHTs are a good indicator of excessively high power settings.
Each of your engine’s cylinders operates differently and has a normal operating temperature of its own. The UBG
is capable of being programmed to take into account each cylinder’s individual operating temperature. When
selecting and programming the CHT limits on the UBG, it is assumed your engine currently does not have a
problem and it is operating properly.
3. Selecting the High CHT Limits: 3. Selecting the High CHT Limits: 3. Selecting the High CHT Limits: 3. Selecting the High CHT Limits: 3. Selecting the High CHT Limits:
Near the middle or end of a long climb, preferably on a hot day, record the CHT readings for each cylinder.
Program the High CHT Limits for each cylinder 40’F above the recorded reading for that cylinder.
Note: Note: Note: Note: Note: The High CHT Limits should not be set higher than the maximum limit allowed for your aircraft.
4. Selecting the Lower CHT Limits: 4. Selecting the Lower CHT Limits: 4. Selecting the Lower CHT Limits: 4. Selecting the Lower CHT Limits: 4. Selecting the Lower CHT Limits:
The CHT Low Limits should be set to 150’F. Operating your aircraft with CHTs below 150’F is not recom-
mended. The large difference between the combustion temperatures and low CHT temperatures can cause
engine damage.
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