JimB

The accuracy of digital engine analyzers

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After I made my first aircraft purchase this year I knew the first thing I wanted to install was a good engine analyzer. I installed an EDM 900 and it really is fantastic. To fantastic in fact. The old analog gauges did their job but now I get to see every little nuance that has probably been with the aircraft for years! My prop speed goes to about 2708-2712 on takeoff, my oil pressure is little low, my oil temp a little high, one cylinder's CHT is probably a little high and another is probably a little low, amps need to be adjusted a little so they don’t read -2 and start flashing at me, etc… I get to see it all in real time and then I get to review a recording of it! :) To make matters worse (or better depending on your point of view) I have paid a guy to nit-pick every parameter so he sends me an analysis of my engine data every once in a while to let me know how my engine is performing compared to others out there (or under-performing ;)) . Anyone else find this true after installing a digital analyzer? 

Note-to-self: quit obsessing over engine data and go fly the damn airplane! All of this is good and I would never go back, but sometimes more detail is not what I need in life…
 

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hahah that is a great point.... I am hot for a 900 because I want to try some LOP flying and with the crummy engine analyzer I have now i don't feel it is safe.

I am really hoping I can find someone that will let me do most of the work to install it and sign off my work.  The installation cost are just crazy!

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1 hour ago, JimB said:

After I made my first aircraft purchase this year I knew the first thing I wanted to install was a good engine analyzer. I installed an EDM 900 and it really is fantastic. To fantastic in fact. The old analog gauges did their job but now I get to see every little nuance that has probably been with the aircraft for years! My prop speed goes to about 2708-2712 on takeoff, my oil pressure is little low, my oil temp a little high, one cylinder's CHT is probably a little high and another is probably a little low, amps need to be adjusted a little so they don’t read -2 and start flashing at me, etc… I get to see it all in real time and then I get to review a recording of it! :) To make matters worse (or better depending on your point of view) I have paid a guy to nit-pick every parameter so he sends me an analysis of my engine data every once in a while to let me know how my engine is performing compared to others out there (or under-performing ;)) . Anyone else find this true after installing a digital analyzer? 

Note-to-self: quit obsessing over engine data and go fly the damn airplane! All of this is good and I would never go back, but sometimes more detail is not what I need in life…
 

I went through the same frustration 4 years ago when I got my EDM900. The early obsession is a good thing and part of the learning process. Switching alarm settings in the device can help. The brain also automatically develops a filter for the TMI stuff it does, and it becomes less of a distraction over time - you simply readjust what you see as normal vs. concerning.  It is  worth poring over your downloaded data early on and understanding what it shows.  Paying for analysis is one good way to learn the types of information that are inherent in the data and learning how to look at the data on your own.  Also, if you look at paid analysis carefully and ask some questions, you will  find that the data is easy to overinterpret - the service  sometimes ascribes potential problems to features of the data that can have other, more benign interpretations. Thinking through these limitations is another part of the learning process.  Despite this learning curve, the monitor really shines is in helping narrow down the problem when something is going wrong. At these moments, it is worth its weight in gold for safety and peace of mind. And the diagnostic efficiency it offers will ultimately offset the cost.

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2 hours ago, JimB said:

Note-to-self: quit obsessing over engine data and go fly the damn airplane! All of this is good and I would never go back, but sometimes more detail is not what I need in life…
 

^^^^^^^ This

I treat my JPI900 like a co-worker that I don't really like.  I just ask it for information when I want it, not when they want to give it to me.    That stoopid fuel pressure too high alarm when it exceeds 6.0 psi really pesters me, particularly on takeoff.   On the other hand, that one time I was rushed through my checklist by an impatient controller and I forgot to enrichen the mixture on takeoff and all those big, bright, yellow color bar EGT readings appeared, I expect the JPI 900 paid for itself several times over.

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Indeed, you have to treat the data with respect, but don't overreact. CHTs, I know they are high on my plane, I was able to bring them down, but then I installed an Electroair ignition and the plane runs hotter. So you deal with it and manage it. Savvyanalisis is a great service but you have to treat the information and their recommendation with some caution. Their recommendations are provided by a software and human interaction is only upon request. 

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2 hours ago, JimB said:

After I made my first aircraft purchase this year I knew the first thing I wanted to install was a good engine analyzer. I installed an EDM 900 and it really is fantastic. To fantastic in fact. The old analog gauges did their job but now I get to see every little nuance that has probably been with the aircraft for years! My prop speed goes to about 2708-2712 on takeoff, my oil pressure is little low, my oil temp a little high, one cylinder's CHT is probably a little high and another is probably a little low, amps need to be adjusted a little so they don’t read -2 and start flashing at me, etc… I get to see it all in real time and then I get to review a recording of it! :) To make matters worse (or better depending on your point of view) I have paid a guy to nit-pick every parameter so he sends me an analysis of my engine data every once in a while to let me know how my engine is performing compared to others out there (or under-performing ;)) . Anyone else find this true after installing a digital analyzer? 

Note-to-self: quit obsessing over engine data and go fly the damn airplane! All of this is good and I would never go back, but sometimes more detail is not what I need in life…
 

I'll be the Debbie Downer here and caution you that repeating alarms need to be addressed on a primary instrument like the 900.  You CANNOT become accustomed to ignoring repeating flashing red lights or alarms.  It's kind of like how now we are NOT supposed to fly around with the stall alarm or the gear up alarm blaring intentionally--that just trains us to tune out those alarms when they occur inadvertently.

Even if there is information that is advisory only, the alarm needs to be addressed.  The amps do not have a specified limit IIRC, and you should adjust the alarm limits on it so it does not flash. 

If the prop speed exceeds 2700 RPM, I assume the alarm limit goes off.  That alarm cannot be changed on the 900 since it is an operating limit, so you should get your shop to adjust the governor appropriately.

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I'm glad I'm not the only one feeling the impact of too much information.  What I know for certain now is that my odd cylinders run hotter than the even side.  So, I've opened the right cowl flap a little to see what that does.  Watching EGT's fluctuate 10 degrees every 10 seconds probably isn't worth getting excited over...

 

 

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12 minutes ago, jaylw314 said:

I'll be the Debbie Downer here and caution you that repeating alarms need to be addressed on a primary instrument like the 900.  You CANNOT become accustomed to ignoring repeating flashing red lights or alarms.  It's kind of like how now we are NOT supposed to fly around with the stall alarm or the gear up alarm blaring intentionally--that just trains us to tune out those alarms when they occur inadvertently.

Even if there is information that is advisory only, the alarm needs to be addressed.  The amps do not have a specified limit IIRC, and you should adjust the alarm limits on it so it does not flash. 

If the prop speed exceeds 2700 RPM, I assume the alarm limit goes off.  That alarm cannot be changed on the 900 since it is an operating limit, so you should get your shop to adjust the governor appropriately.

Thanks Debbie! :D Yes I am aware of all of that. My point was that I am certain the engine has been running at those rpms every takeoff for years and no one would know or really care since you don't have the precision on the old analog gauge and certainly no alarm to flash. I suppose I should get around to adjusting it down 10-15 rpm...

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And on the subject of ignoring advisory alarms, I would guess that everyone gets the yellow oil pressure alarm while on the ground at lower power settings? I know I do and it isn't adjustable so you really don't have a choice except to ignore it. 

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A friend put an engine analyzer in his antique taildragger. Now he has all kinds of problems with the engine that's been running in that thing since the 1940's.

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Just think how bad it is for the poor guys running the EDM-830. They've got BOTH the digital and the old fashioned analogue gauges which can never agree exactly. So which do you believe?

The CRM in my cockpit has George responsible for the flying with JPI and I responsible for the engine. I treat the JPI like my best friend in the cockpit. Which is to say I know what to expect and that includes the little fluctuations in numbers across the board. But I know it well enough that I know when its story has changed and there is something that I need to address.

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1 hour ago, JimB said:

And on the subject of ignoring advisory alarms, I would guess that everyone gets the yellow oil pressure alarm while on the ground at lower power settings? I know I do and it isn't adjustable so you really don't have a choice except to ignore it. 

Top of the yellow arc is pretty common for me on the ground at low idle.  Having it drop out of the green at any other time would indeed be alarming, so I’d want the alarm to stay. This is where the flashing red warning of the digital instrument could be a lifesaver.

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2 hours ago, JimB said:

And on the subject of ignoring advisory alarms, I would guess that everyone gets the yellow oil pressure alarm while on the ground at lower power settings? I know I do and it isn't adjustable so you really don't have a choice except to ignore it. 

AFAIK, alarms that are operating limitations are required to be alarmed in red.  You should get in the habit of deferring other alerts during high workload/high risk phases of flight otherwise (takeoffs, landings, go-arounds, etc). Flashing red should get your attention always.

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2 hours ago, steingar said:

A friend put an engine analyzer in his antique taildragger. Now he has all kinds of problems with the engine that's been running in that thing since the 1940's.

A couple years ago I wound up AOG and had to leave the airplane at the shop on the field.   While they wound up doing really excellent work, the guy was very anti-technology.   Didn't do email, the work record and invoice and receipt were hand-written.   I was chatting with him about engine monitors and his response was, "You're really better off not knowing."

I thought that was pretty funny, because he was serious and there really is some truth to it in some ways.

OTOH, I really love the engine monitor, but I'm a data-driven engineer, so we're pretty compatible that way.

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Back in the 80's Harley offered several gauges as accessories that mounted in the fairing of their Touring models, Oil PSI and CHT were 2 of the gauges offered. Owners would freak out after installation, claiming it was running TOO hot or themed watch their oil pressure go to "0" at idle, it was difficult to explain that 350ish on CHT was normal and not to worry about no oil pressure.....lol

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20 minutes ago, EricJ said:   I was chatting with him about engine monitors and his response was, "You're really better off not knowing."

He meant “I’m better with you not knowing”

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I occasionally hear from the more seasoned A&P's how these airplanes flew for over 50 years without engine monitors. But then the same guys say you should never run LOP and my turbo Mooney will need a Top half way to TBO. 

So I got an engine monitor and learned how to use it. I fly LOP all the time and just might get to TBO on the original cylinders. 

I'm at 1600 hours, and she's in annual right now. Borescope came back clean, and compressions are good across the board. We'll go another year, and 200 hours will be TBO.

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it gives you something to do in Cruise.   And for that it is worth the money.

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The cool thing with a jpi900...

If you can’t tell what is going on... download the data, post to Savvy, share link here.

Try that with your analog gauges... post a video of them wagging in flight?

Make sure all the instruments are reading properly before trusting them... same as the analog ones...

Best regards,

-a-

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