An Engine Monitor for N1071Z
Post date: Aug 22, 2020 4:43:56 PM
Why Install an Engine Monitor in 71Z
Recent incidents when the plane lost power during flight were due to a sticking exhaust valve. Another related earlier indicator was rough running from lead fouled spark plugs. While we had warning signs, we were not able to get the issues diagnosed before we wound up with a $2000 bill for a new cylinder and new piston after the piston struck an exhaust valve that was stuck open.
What led to this incident, and how can we avoid a recurrence?
Running the engine too rich results in the exhaust gases and engine staying much cooler. One might think that cooler is better, but this is not so. While running too hot can damage an engine, so can running too cool. When the engine runs too cool, the lead and combustion products return to a liquid form before they are expelled completely from the engine -- coating spark plugs and valves, gunking things up, making cold valves stick, and causing hot spots that can trigger pre-ignition. At ideal temperatures the lead and combustion products stay gaseous well into the exhaust system.
By installing an engine monitor, Wing Nuts members will be able to more effectively lean the mixture during all phases of flight to maintain optimal cylinder head temperatures of 360-380ºF.
Additionally, an engine monitor will record data from every flight to an SD card and enable non-invasive evaluation and diagnostics of engine issues on a regular basis (like we’re doing with 7AM and 4SG).
Spark Chasers has extensive experience installing JPI engine monitors and recommends the EDM-830 for 71Z.
The EDM-830 displays a comprehensive picture of how the engine is performing and will track fuel flow so pilots can more closely monitor fuel usage on long trips (more like what we’re used to with the G1000). All the sensor data is logged to an SD card for regular offline engine analysis.
Specific sensors included in the EDM-830 are as follows:
Cylinder Head Temperature (CHT)
Exhaust Gas Temperature (EGT)
Voltage
Fuel Flow (USED, Remaining, GPH Endurance, GPS destination)
MAP (Manifold pressure)
Oil Temperature
Oil Pressure
OAT
%HP (Requires: OAT, RPM, MAP, & FF )
The unit is not certified as a primary instrument, so the engine monitor will supplement the existing factory engine gauges. There’s an open spot on our panel to the right of the analog RPM gauge above the throttle where the engine monitor can be installed.
Estimated Installation Cost
EDM-830 is approximately $8508
Cost Breakdown
EDM-830 = $7758 unit with installation + $150 consumables + $400 to $600 labor to cut the panel
Estimated Installation Timeline
Current installation lead time is about 6-8 weeks from time commitment is made.
Installation of the EDM830 is about a five day project.
We would schedule to drop off the plane on a Sunday evening or Monday morning, and should be complete by Friday afternoon.
Recommendation
The board’s recommendation is to install the EDM-830. It will make a huge difference in allowing club members to better care for the engine in 71Z.
References
Product information
https://www.jpinstruments.com/shop/edm-8301/
Why valves stick: How you can avoid engine damage and power loss https://www.aopa.org/news-and-media/all-news/2020/july/pilot/savvy-maintance-valves
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