Engine scare

[flyboy0681]

55 minutes ago, takair said:

Wow, that is some rapid degradation.  We always hope to see a longer failure trend than one flight.  Makes one think hard about not checking oil every flight... 

Im sure you would have mentioned it if you saw it, but I am surprised the EGT on the guilty cylinder didn't move.  That makes this one even more of an evil scenario.  Glad you guys landed with the two quarts...they at least got you down.

One thing that I forgot to mention about warning signs, as I have written here over the past year, the engine has been running hot and while we have tried to get to the root cause, we never solved it. A typical flight has been conducted with cowl flaps open and mixture more rich than I would have liked. We kept adjusting the baffles but it's starting to make sense that there was something more insidious going on which contributed to the situation. Most experts that I've spoken to believe the high temperatures were gunking up the oil to make sludge.

[gsxrpilot]

1 hour ago, takair said:

Im curious if you know the update rate on your recorded data.  I want to see my sample rate is every 6 seconds.  If I added the recording feature do you think that would catch this type of valve problem?  Seems the sample rate may be too slow...that said, the thermocouple saturation time is quite slow too.  Or do you see the leak/wobble over a longer period.  I suppose this is where the fast acting thermocouple can be beneficial.

My JPI EDM-700 is sampling data at a rate of 3 times per second, but is only recording at a rate of every 2 seconds.

[bradp]

With the EDM-730 / 830 you can change the recorded sampling rate up to 2 seconds from the default of 6.  I don't know how many flight hours it takes to fill up the memory - frequent downloading of the data may be advisable if you turn the recording rate up.

 

[Marauder]

3 hours ago, bradp said:

With the EDM-730 / 830 you can change the recorded sampling rate up to 2 seconds from the default of 6.  I don't know how many flight hours it takes to fill up the memory - frequent downloading of the data may be advisable if you turn the recording rate up.

 

A lot. i have my 900 set for a 1 sampling rate and I never had a problem with it filling up.

[cnoe]

With newer engines having improved valve guide materials it's much more likely to experience sticky valves than excessively wobbly valves in the Lycoming 360. You may want to take a look at SI-1425A and SB-388C (attached) for a full understanding of the problem. It sounds like this is what cased your bent valve. There are warning signs if you listen. And yes, install an engine monitor.  P.S. Nice job on your problem management.

Lycoming SB_388C.pdf

SI_1425A_Suggested_Maintenance_Procedures_to_Reduce_the_Possib_ility_of_Valve_Sticking.pdf