1. 777 Neptune Groundschool
Instruments & Gauges

2. Oil Pressure Gauge
The Oil Pressure Gauge indicates the oil pressure supplied by the oil pump to lubricate the engine
Located on the instrument panel
Units are pounds (lbs) per square inch (PSI)
High oil pressure indicates the oil is viscous (flowing sluggishly)
Common in cold temperatures
If too high oil could be forced into the combustion camber
Low oil pressure indicates oil is not viscous enough
Over heating or possibly a leak

3. Oil Pressure

4. Oil Temperature Gauge
The Oil Temperature Gauge indicates the oil temperature in Fahrenheit or Celsius
Located next to the pressure gauge on the instrument panel
Strict relationship between oil temperature and pressure
High pressure is usually coupled with low temperatures
Oil within its normal temperature operating range will show normal pressure
Pressure and temperature should change with each other, uncoupled changes (temperature lowering without pressure rising) usually indicates something undesirable

5. Oil Temperature

6. Cylinder Head Temperature
The Cylinder Head Temperature Guage records the temperature of one (or more) engine cylinder heads
Indicates how effective the engine is being cooled
Should be monitored during frequent steep climbs
High engine temperatures may result in detonation, preignition and, eventually engine failure
Lean and Rich settings observe different temerpatures

7. Cylinder Head Temperature

8. Tachometer
The Tachometer indicates the speed in which the crankshaft is turning in hundreds of revolutions per minute
Units are RPM (rotations per minute) in reference to rotations of the axil via the engine
Also keeps an accurate record of engine hours (hobbs time)
4 arcs
Green – normal operating range
Yellow – caution range
Red – maximum allowable

9. Tachometer

10. Manifold Pressure
The Manifold Pressure Gage indicates the presuure of the fuel / air mixture in the engine intake manifold (between the carburetor and cylinders)
Units are in inches of Hg
When the engine is not running the manifold pressure gage will indicate the sea level pressure
A drop in the manifold pressure gauge may be an indication of carburetor icing

11. Manifold Pressure

12. Intake manifold