EDM 830

[aajones5]

Ladies and gentlemen after months of waiting and preparation, I've finally got my EDM 830 installed! I couldn't be happier with the job that Auric Avionics did in installing it, unfortunately I can't post pics right now but they'll be up as soon as I can. Installation took 39 hours so right where I was expecting. However on the flight back home I noticed a lot of things that seemed weird. First off the MAP was always about an inch above what my factory gauge was reading and the RPM was always about 100rpm lower than what my factory tach was reading. As far as leaning my cylinder EGT spread was about 100-120F I'm not sure if this is a big spread, I flew in a cirrus yesterday that had spreads of 30F. I tried leaning LOP but it seems like once I peak the hottest cylinder I can only go about 20-40F cooler on that cylinder before my engine starts running really rough. Is it just impossible to get LOP with my engine or does that mean theres something wrong? Also on climbout my hottest CHT will always go above 450F and start the alarm, I'm usually doing about 100mph for the first 400ft and then I start to transition to 120mph, but does this mean I just need to pull the power back quicker on climbout? My fuel flow and fuel used has been very accurate so far so no complaints there. I've also noticed that on takeoff when I go full power my %HP only gets to about 75% and I'm around sea level all though it is pretty hot. I think this partially has to do with the fact that I've noticed my OAT on the EDM doesn't match up my other OAT gauge I have. It reads a lot higher on the EDM, but my other gauge matches up better with the temperature that it feels like outside as well as what it says the temp should be on the winds aloft charts. So I'm wondering was the sensor installed wrong. And finally my carb temp was not what I was expecting. When I'm taxiing it says its above 100F even when its 85F outside and during cruise it will read about 7F warmer then the outside air and only when I start descending do I see it drop to the OAT or slightly lower (and this is compared to my non-EDM OAT). Thanks guys and sorry for the excessively long post.

[N601RX]

Many of the things you mentioned has correction factors inside the edm that must be entered as par of the install process. This is covered in the install and operation manuals. 

[carusoam]

The more you know, the more questions you will have...

Do a search on running LOP with an O360.

Hank has done some of the best explaining on steps that can be taken.

There is not a lot of data available to share since FF and EGT data for M20Cs is in tight supply.

Welcome to the Modern M20C world!

One way to check your tach data. Get an app for your phone and measure the engine rpm.  It uses sound... Expect the old cable might be a bit slow leading to the ship's gauge.

Your mechanic can adjust the gauges using independent standard gauges he has.  Keep in mind some ship's gauges haven't been touched since they left the factory.  The original tach has a micro  oil cup on its back side. Do you remember putting oil in it?

Best regards,

-a-

Edited June 3, 2017 by carusoam

[aajones5]

Ok so I had to do some corrections on the MAP and OAT and all that is good now. Mainly I'm trying to figure out the leaning portion now, I was flying at 50% power today and just couldn't get it LOP very far at all, I had the hottest cylinder slightly lean of the peak but the other were still ROP and the engine gets really rough. I've also noticed that my #3 cylinder seems to be significantly hotter than the others, around 150F hotter on the EGT while the others were pretty close together as well as the CHT is usually between 400-450F on the climb while the others are below 400. I'm wondering if there's any danger of running that hottest cylinder at peak with the others cooler because that's the only way I can get a FF that's at or below the POH values.

[Bob - S50]

You have an O-360, no injection.  You may not be able to run LOP because of fuel distribution.  Some of the Pelican's Perch articles talk about trying to run LOP with a carburetor.  If I remember right, it says you MAY have better luck if you do two things:

1.  Pull the throttle back just a hair off of full throttle (if it isn't already back).  This puts the throttle plate at a slight angle and MAY help stir the fuel mixture for a more even distribution.

2.  Try just a little bit of carb heat.  Supposedly this MAY help to atomize the mixture a bit better.

[aajones5]

I tried both of these things today just not at the same time, I'll have to keep working on it.

[cnoe]

Also keep in mind that the "hottest" cylinder (EGT) isn't necessarily the 1st to peak when leaning.

 

The "actual" EGT value isn't important unless it's indicative of a non-firing plug which would cause it to read significantly higher than the others. If you're curious, measure your probes' distances from the flanges in the exhaust risers and see if they're the same (which still won't necessarily equalize the temps). Also [mention=11970]gsxrpilot[/mention] has good experience running the C LOP; check his posts.

 

 

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