EDM-700 is Precision Engine Performance

Why Measure Temperature?

An old and common misconception that other manufacturers of EGT monitors promote is that it is not necessary to know the exact exhaust gas temperatures of your aircraft's engine. However, if you have read recent reports, shock cooling can be catastrophic! The EDM alerts the pilot of those conditions which are most vital to the maintenance of well performing engine. The value in measuring EGT lies in finding the ideal ratio of fuel to air that results in complete combustion, and in long-term trend monitoring.

Long Term trend Monitoring:

Trend monitoring will identify thosesmall problems before they turn into serious engine damage. It is the most important tool for diagnosing engine problems, and it works! Digital displays make all the difference obvious. Trend monitoring is simply not possible with just a bar graph indicator. Yet, with only a digital indicator, quick glance temperature recognition is not possible either. With a digital display, engine data can be recorded by the pilot in a log book on a monthly basis. EGT and CHT will group themselves into a tight pattern at specific MAP & RPM. As a problem begins to develop in one or more cylinders, the EGT span will start to enlarge. The DIFF mode "dot" will identify the problem cylinder causing the large span. Factory new injected engines have a typical span of 80ºF, carburated 140ºF.

Leanfind Mode:

The EDM-700 identifies the optimum mixture accurately and automatically. After cruise power has been established, the pilot just presses the function button of the LEANFIND "LF" mode. As the pilot begins to lean the mixture, the EDM-700 is checking all cylinders, using a propriety algorithm looking for the first cylinder to achieve peak EGT. "PEAK EGT" will be displayed when the first cylinder to peak is detected. The display will also then flash the cylinder column and show peak EGT. The pilot has the option to increase (the richness of the mixture) or operate at peak. Leaning faster than the engine can respond will cause the display to flash "2 FAST." The EDM is monitoring all alarms in the background and if the TIT limit is exceeded during the Lean Find process, the TIT column will flash first. Some turbocharged engines do peak TIT before the EGT peaks.

Since 1995, pre-ignition and detonation have become more prevalent with the new fuels available. Therefore it is of the utmost importance to monitor ALL EGT's at one time during climbing, and leaning. Pre-ignition once started, causes an extreme temperature rise and is self sustaining until engine failure occurs, which can be in less than one minute. Pre-ignition will cause the EDM's bar graph to reach maximum height on that cylinder. Seeing all cylinders at once will permit the immediate action required by the pilot.

Consider Economics:

For example, a Beech Bonanza with an 0-470 engine at 10,000 ft. @ 65% power and fuel at $2.20 per gal. At a true airspeed of 160 mph and a peak EGT, this engine consumes 11 gph. This means that in 500 hours, the Bonanza will consume $12,000 in fuel.

Most pilots not knowing which cylinder peaks first, operate at a 75 to 100 degrees rich of peak. Too rich of a condition causes vibration and carbon deposits in the engine. Flying under such conditions, a very rich mixture would result in an increase airspeed of 2 mph, while the fuel burned would increase by 2.2 gph. If the EDM was used to lean the engine only 10 degrees rich of the peak, the plane would cost 20% less to operate or $2420.

EDM-700 Data Recorder:

A complete engine data recording system. Capable of recording not only EGT and CHT as some less sophisticated systems do, but also can record all 24 engine temperatures, plus all engine pressures, RPM and can calculate percent of horsepower. The ability to print out alarm conditions, with three dimensional color data analysis of your computer, is also a feature.

Additional Functions Required for Automatic Data Recording:

Diagnosing an engine problem is a very complex task, requiring the data from several engine instruments. Recording EGT & TIT temperatures is only the start. In order to fully understand the engine, RPM, MAP, OIL TEMP., are also required. This is why you should not be misled by less sophisticated copies that claim data recording capabilities. These gauges simply don't record the necessary information to make a thorough engine problem diagnosis. For example, a large drop in EGT could be a serious problem developing or just the addition of full throttle. JPI realized this at the beginning of the development of its EDM data recorder.

Manifold Air Pressure (MAP):

Precise manifold air pressure is required to measure accurate engine power levels. The EDM's precision solid state transducers measure MAP to an accuracy of 1/10 inch of Hg. Rpm is measured within one RPM as well. As a pilot, you know, it takes both RPM and MAP to calculate Percent of Horsepower. Both are recorded with the EDM.

Percent of Horsepower:

JPI's proprietary algorithm calculates and displays percent of horsepower from carburated, normally aspirated, high performance injected, turbocharged and inter cooled engines. Try taking off from a high density altitude airport by setting maximum HP before releasing the brakes.