Engine monitor
A window into the powerplant
Thankfully, we have evolved. Digital engine monitors are now available that gather, analyze, display, and record dozens of parameters every second (or faster). With this information we can monitor the acute and long-term health of the engine, know the correct fuel burn to the tenth of a gallon, and diagnose everything from burned valves to spark plug problems.
Engine monitors are effectively little computers in the format of a cockpit panel-mounted display that gives the pilot temperatures, pressures, and other values. The numbers come directly from thermocouple and other types of probes. The cylinder head temperature probe is mounted via a hole that comes pre-drilled from the engine manufacturer. Exhaust gas temperature comes from a probe that sits two to four inches from the exhaust flange. Fuel burn is calculated via a fuel transducer. These clever little boxes have a wheel that spins when fuel flows past. There’s an infrared light on one side, and a sensor on the other. The computer calculates the rate at which the wheel interrupts the light, which determines the rate of flow, and therefore, the amount of fuel flowing past.
All these wires pass through the engine firewall and are plugged into the back of the unit with a Sub-D connector. After a little programming to make sure the fuel flow, percentage of horsepower, and other parameters are correct, the pilot can fly confidently, controlling cylinder head temperature below factory limits, and analyzing the data to ensure the long-term health of the engine.
