EMS or Skyview exhaust valve monitoring

[DrewSwenson]

Mike Busch (in many articles) talks about reviewing engine data post flight to look for the symptom of exhaust valve failure (slow EGT oscillation with a frequency around 1 cycle per minute with an amplitude of 30 to 100 F).

https://www.aopa.org/news-and-media/all-news/2014/july/08/savvy

Any thought to adding a real time warning to both the EMS and Skyview products?

 

[airguy]

It would be exceedingly difficult, I would think, to pick this up in realtime while excluding factors like throttle, mixture and rpm changes, or airspeed changes (climbs/descents) that change the cooling airflow on the cylinders.

 

[DrewSwenson]

It would be exceedingly difficult, I would think, to pick this up in realtime while excluding factors like throttle, mixture and rpm changes, or airspeed changes (climbs/descents) that change the cooling airflow on the cylinders.

Two ways to implement:
1. you are looking for a frequency and an amplitude excursion.....so the throttle, mixture, rpm, etc would put you outside those parameters (no indication of valve issues....or "unknowable".

or 2. you could steady up on alt, speed, mixture, rpm, etc...then push a soft button that does an analysis over the next 10 seconds or so....which pops off a result.

 

[dlloyd]

Over the course of 6000+ hours I had several (6?) exhaust valve failures, all from one Cont. reman. Only one gave the oscillating EGT indication Mike Busch describes. You would probably notice an EGT tracking up and down for many hours before the valve failed. Also had two stuck exhaust valves, one Cont, one Lycoming. Neither gave any hint of a problem prior.

 

[dynonsupport]

So as an FYI, we took your request to look into this, and talked to Savvy. They say that while FEVA works great offline, based on their experience with FEVA over the last two years, the current algorithm it isn't something they believe could currently be put into an engine monitor for real time monitoring and provide reliable data.

We'll keep in touch with them as they keep refining their algorithms and maybe in the future we'll be able to integrate it. Thanks for the suggestion!