M20K 231 - fitting an engine monitor

[tmo]

Unfortunately panel space is at a premium and going to a dual Aspen while installing an engine monitor would be somewhat overkill

The only place it would possibly fit is the right panel, where the stormscope is.

I probably should leave it at "good enough" with the EDM900 and spend the extra $2k on a PMA450B...

[gsxrpilot]

12 hours ago, tmo said:

Thanks to all, again, for all the input.  The A&P has spoken and he said JPI, so that's that.  Guess I need a second plane to put an EI in it ;-)  I always wanted a taildragger...

I now have a question for the 6 cylinder turbocharged crowd - @gsxrpilot et consortes - I know, landscape, but exactly why?  Looking at the pretty pictures on the interwebs, eg. this picture from JPI the main difference I see is that only one of CHT/EGT will be displayed, all else being seemingly equal.  Do I really care that much about EGT values in real time, if I have TIT and it's all getting recorded for upload to Savvy anyway?  Won't the device pop an alert if there is something I do need to look at?  OK, the RPM/MP gauges are slightly different, but is it really significant?  It seems easier to fit it in portrait mode, and I'd need to remove one less instrument, hence my question.

A side question, if I may, is about EDM900 vs EDM930 - are they really "functionally equivalent" and the only difference is a bigger screen, or is the 930 a significantly better unit?  I guess I should leave it at "plenty good enough" (900) but hey, Christmas is coming...  JPI has a presentation about the differences which tries to suggest the 930 is much better, but I don't really know if it is better for me to buy it for my plane, or for JPI to sell it to me at a better margin...  The 900 seems to display and log everything I need, so that's the "good enough" angle.

Last set of questions for now are about IAT.  I am planning to add an intercooler at some point in time, hopefully soon, and thought about getting IAT on the JPI to future-proof it.  Q1: am I making sense?  Q2,3: how is IAT displayed and does the JPI also show the temp delta, like the unit that comes with the intercooler; Q4: does the JPI replace the IAT indicator provided with the intercooler, or will I need to install the second unit as well?

You understand it correctly. The only difference with portrait mode is the lack of EGT/CHT numbers. I don't care about the EGT's so much, but I like having all CHT numbers on the screen all the time. I just don't want to have to scroll through screens. I want to see all my data all the time. I spend more time watching the engine monitor than any other instrument in my panel. 

The EDM 930 is only a larger screen. It was more important for me to have the screen on the left side of the panel rather than a larger screen but over on the right side. In my previous Mooney, I had the engine monitor on the right side and didn't like it there at all. So it was worth it to me to get the 900, in landscape mode, left side of the panel.

My 252 comes with an intercooler, but I don't have the IAT probe. I'm not sure what it would do for me, so I didn't get it.

I will say that the portrait/landscape issue is the most minor of all issues. I think you'd be happy with either.

[MIm20c]

I do find it annoying when doing a mag check not to see the egt values. Is there a way to cycle back and forth between the two?

[gsxrpilot]

1 minute ago, MIm20c said:

I do find it annoying when doing a mag check not to see the egt values. Is there a way to cycle back and forth between the two?

I just switch to "normalized" when doing a mag check. Then the numbers don't make much difference.

[carusoam]

There are a few people that have the large format JPI 930 around here... it often gets located in the right/co-pilot panel...

EI also has a large format engine monitor 

We have two resources if you have questions...

one is Jeev who sells the JPI product and can get deep detailed answers to tough questions...

The other is Oregon, an EI guy that is often on MS...

 

Most people prefer the small format 900 to replace primary instruments... and squeeze it into the left side panel any way it fits...

Horizontal is better... as mentioned more data displayed while horizontal...

The value of all the Extra EGT data is not so much for normal operations.... but it sure is handy if you see a fuel injector misbehaving in flight...

PP thoughts only, not a mechanic...

Best regards,

-a-

[MIm20c]

7 minutes ago, gsxrpilot said:

I just switch to "normalized" when doing a mag check. Then the numbers don't make much difference.

I always forget to do that. It would be a lot more sensitive to observe changes in cruise as well. 

[81X]

I'm absolutely terrified for what you're going to find on how hot you've been running your engine.  My factory heat gauges are nothing short of a polished turd, although ironically the fuel gauges are super accurate.  My 231 has had a JPI in it for the longest time and I'm about 1450 SMOH on the original cylinders with great valve patterns.  Heat management is key on the 231, you're doing one of the best wallet modifications you can for your 231 (in a good way)

I have a JPI EDM-830 and it's great.  Great data, cost effective, you can add onto it over the years, etc.  I really like it in landscape mode just to the left of the center stack.  As others have said, the 900 or 930 are great choices if you want to ditch the factory gauges.  

I'm big on landscape mode, and every startup, I press step and have it "stick" to TIT.  great for managing power LOP and ROP.  Photo below from my 231.  

[jlunseth]

I re-did my panel shortly after I bought my 231 a decade ago.  I had a JPI 930 installed, landscape mode, on the pilot side panel to the right of the 6 pack instruments.  We also moved the AP annunciator over to the top of the pilot side panel, so the annunciation are right in the pilot scan, as are all the engine readouts (except vac.).  This arrangement is excellent from an ergonomics and safety standpoint.  In IMC, having the AP annunciator and all the engine readouts in my direct scan allows me to know what the AP is doing and the exact condition of the engine.  I had the metal panel itself replaced, but not really to relocate things, that is dictated by the cages/trays behind the panel.  There was plenty of room on the pilot side to do it.  The JPI 930 certified primary allows taking out all the engine strip gauges, the MP and RPM wherever you have them.  Having the MP way over on the right side was a major pain especially in the 231, where the pilot manages MP.  In the middle I have an MX20 and 430 AW.  I am currently getting quotes to replace the MX20 with a GTN 750, which will free up a ton of space on the right side.  My Comm 2, KNS 80, and probably my old King ADF will all come out.  I have right side pictures by not left, I will get some and post.

[Oldguy]

4 hours ago, jlunseth said:

 In the middle I have an MX20 and 430 AW.  I am currently getting quotes to replace the MX20 with a GTN 750, which will free up a ton of space on the right side.

What else are you taking out of the center so you can fit the 750? The MX 20 is 5" tall while the GTN 750 is 6".

The only thing to use the same space as the MX is the Avidyne 540/550 or the GNS 530.

[tmo]

See towards the end of the post - he's removing the KNS80, that thing is huge, plus com, plus ADF.

[jlunseth]

42 minutes ago, Oldguy said:

What else are you taking out of the center so you can fit the 750? The MX 20 is 5" tall while the GTN 750 is 6".

The only thing to use the same space as the MX is the Avidyne 540/550 or the GNS 530.

Yes, I know about the height difference, my avionics shop is checking on that.  There is room at the bottom of the stack, the open question is whether it is enough.  The center stack currently is the aircraft annunicator strip at the top, then a PM8000, MX20, and the 430 AW.  There are a couple of blank inches left at the bottom.  If that doesn’t work, the Comm 2, KNS 80, and old ADF, and a KT 74 are on the co-pilot side, the KNS 80, Comm 2 and probably the ADF will come out, leaving lots of room for the 430 AW as the backup GPS. I don’t have a pic of the entire pilot side, but you can see the JPI and where it fits.  The six pack is to the left of that.  The CDI in the picture is a second CDI connected to the KNS 80, the primary is the 256 HSI that is part of the six pack.  I like the KNS 80, but no good reason to keep it with two good GPS units.

[jlunseth]

The little bar above the JPI is the Remote Alert Display, required to have the JPI serve as primary.  It is a sort of backup for the JPI.  The 430 currently connects to the HSI, with an Icarus SAM GPSS in between to convert the digital signal for the AP.  I will have the 750 drive the HSI and AP, and the 430 will connect to that second CDI as a backup.

[Phil EF]

I have a K and a 900 ready to install.  The simplest method I found was remove the ADF indicator and move the CDI left into the Now empty space. Mine has an empty slot at the left end of the row of rocker switches that the primer switch will fit in. The go-around button can go almost anywhere due to small footprint. This setup allows the autopilot annunciator to remain in place and requires virtually no additional cuts in the panel. 

[Oldguy]

On 11/29/2019 at 3:40 PM, jlunseth said:

Yes, I know about the height difference, my avionics shop is checking on that.  There is room at the bottom of the stack, the open question is whether it is enough.  The center stack currently is the aircraft annunicator strip at the top, then a PM8000, MX20, and the 430 AW.  There are a couple of blank inches left at the bottom.  If that doesn’t work, the Comm 2, KNS 80, and old ADF, and a KT 74 are on the co-pilot side, the KNS 80, Comm 2 and probably the ADF will come out, leaving lots of room for the 430 AW as the backup GPS. I don’t have a pic of the entire pilot side, but you can see the JPI and where it fits.  The six pack is to the left of that.  The CDI in the picture is a second CDI connected to the KNS 80, the primary is the 256 HSI that is part of the six pack.  I like the KNS 80, but no good reason to keep it with two good GPS units.

Yeah, with the space you have below, it should not be a problem. The only pain is the trays in a Mooney are riveted into the stack, so a little more labor, but you should be good to go.

Gonna be a nice panel when you are done!

[Jim F]

I installed a 830 8 years ago over on the co-pilots side up high.  I found it not always in my scan.

This year I moved it right above the engine controls and I really like this position. 

[jlunseth]

When the 930 was installed there was no portrait layout, primary certified engine monitor as I recall.  Might have done portrait had it been available.  However, as I recall, I needed to display Compressor Discharge Temp, which has a required redline in the 231. Might not have had a choice between portrait and landscape with the CDT bar being required, don’t really remember that part very well.  Worth checking into (what readouts you must have for the 231). If you have an intercooler you might need to install Induction Air Temp also, but I don’t believe that needs to be displayed on a bar, it is not a redline limitation, you can just have it display in the scrolled data.  I believe the difference between CDT and IAT is needed to make power settings under the STC for the intercooler.  Turboplus supplies a chart.  It isn’t worth much, better science says that the intercooler does not yield as great an increase in air molecules in the induction system as the intercooler manufacturers used in creating the power charts, but it is still required.  

[johncuyle]

On 11/9/2019 at 8:28 AM, tmo said:

I know there are CGR users out there, hence my surprise.  With the dual CGR30's (P and C) I believe I can replace everything primary, as I can with the EDM900, but will do the math for sure.  The worksheet that needs to be filled out and sent in will keep me (and my A&P) honest.

I forgot - yes on the CIES fuel senders, thanks for that suggestion; I was somewhat on a fence on those but yes, it simply makes sense to do it right from the start.

I'm running the CGR combo setup, in a panel similar to yours.  I yanked the ADF and had the second CDI moved to the ADF slot and have the C where your backup AI is and the P where your CDI is.  Occasionally wish I went with the MVP-50 sometimes, but there just doesn't seem to be a good place to fit it.  Same problem with the 930, which I like.  I don't like the 900 and I'm not sure it can be primary for all the instruments you need to yank all the legacy ones.  CGR is a good setup and works well for the plane.  Added on the CO detector, though I'm not sure it works, and also don't have a GPS feed for some reason.  Also did not do the fuel senders at the same time.  That'll be a future upgrade.  There were some minor teething issues with the install that got wrapped up and it's been working great since. 

I think the dual round gauge form factor is a good fit for a 231 panel layout.  At some point I'll probably go G3X or G500, but I think when the panel is "done" I'll end up with a GTN 750 and a GTN 650 (overkill, but I want the 750 and have a 650.  If I had the 750 I would probably go with the GNC355.  At least I get a backup VOR and ILS out of it) with the 10" screen in place of the six pack, a pair of G5's vertically stacked to the right of that as my backups, and the CGR's vertically stacked to the right of those, with a GFC 500 with the AP display up where the old strip gauges were, making room above where your backup CDI is.  Ipad mount on the right, in front of the passenger.

Anyway, I definitely like the CGR.  I like the way it works, I like the displays, I like the flexibility the form factor gives me, I like the warning ranges I have set on it (mine's intercooled, I had them configure it to go yellow between 36" and 40" MP) I like that I have an integrated CO meter, I like that I have all my primary instruments right there on two displays, I like that when my panel is done my "cruise configuration" scan will be able to include the CGRs and the G5's right in that tight space unlike if I had a 50 on the other side of the panel, and so on.  

[tmo]

Hit a bit of a snag on the way, but things are moving again, and I would like to ask for confirmation on a couple questions we're not sure about.

Can someone please confirm that the stock 1980 M20K fuel senders are:

• resistive
• 2 in series in each tank (total of 4, but since in series, they count as 2 inputs for the EDM)

Tell me what values for fuel pressure should I put in the order form - can't find anything in the POH, but I want the FP logged just in case.  I got 6.25 PSI as min and 38 PSI as max from Continental SID97-3G, but want to confirm.

Since the fuel senders I have are working fine, I'll opt to not spend the $1600 and pass on the CIES senders for now, especially that they can be replaced without sending the EDM back to JPI, just a matter of purchasing the right ones.

[LANCECASPER]

39 minutes ago, tmo said:

Since the fuel senders I have are working fine, I'll opt to not spend the $1600 and pass on the CIES senders for now, especially that they can be replaced without sending the EDM back to JPI, just a matter of purchasing the right ones.

I think if you later go to the CIES senders, the EDM must go back to JPI.

[tmo]

I beg to differ, I believe the newer CIES senders can be had in a version that emulates the original resistive (?) ones, at a slight loss of resolution.

See these instructions about EDM-900 from CIES for reference.

Also the CIES product page lists "resistive output - existing gauge" from which I would deduct the EDM won't know either.

The EDM would have to go back to JPI if one wanted to go with digital senders from CIES.  Again, I believe the real difference between them is the resolution, not accuracy.

Edited December 10, 2019 by tmo

[LANCECASPER]

My mistake. I never thought anyone would be willing to pay for digital senders and then have them send analog signals.

[carusoam]

Expect the analog signal to not carry the same high accuracy as the frequency signal...

On the newer JPIs there is the ability to flip a software(?) switch, to not have to send it back to the factory...

Things to look into...

The original resistive fuel level sensors are in series so they are additive... when fuel is under one float, after moving away from the other float... the total fuel level doesn’t change...

We have the Cies guy here if you want to ask him questions... @fuellevel...  sales guy and engineer in one person.
 

TMO, check on the resolution as well... it makes a lot of sense to go to the higher resolution when you can...

PP thoughts only, not a mechanic... so check my math before going out and using this idea...
 

Best regards,

-a-

[fuellevel]

That is correct it is now field configuration software switch change. No need to send back. Only throw away the JPI resistive to voltage conversion boxes when you go digital


Sent from my iPad using Tapatalk

[jlunseth]

I added the CiES senders and sent the 930 back to JPI. i now have actual, working, accurate fuel gauges.  Its worth it.  The factory senders were always squirelly, reading 0 when there was ten gallons left in my 37 gallon tanks, or flying on full for a couple of hours and then suddenly jumping to less than half a tank, it is really nice to know how much fuel is there, I highly recommend it.  The only problem was that when JPI re-did the panel, what I got back has the dimmer circuit in it, and the panel would dim to black and sunset and would not be recoverable.  Unfortunately the RAD would do the same thing, so no engine read-outs at all.  We sent it back in and it is better, but not best.  It dims out on its own now, but not to completely black, and allows me to use the BRT function to bring the panel back up to visible again.  It is a pain when it does that on its own, because it dims to below visible level, at least to my eyes, but not to completely out and unrecoverable.  It is a known issue, I found it on the Beech board, we are going to send it in for further adjustment when annual time comes this year.

[tmo]

So, two more, similar, questions... 

The JPI documents don't say if the fuel indications are primary or not, yet it seems to be OK to remove the original gauges, how so?

The JPI documentation clearly states that the AMPS are non-primary.  Is the basis for being able to remove the original AMPS gauge that it isn't listed as a primary source of info in the limitations section of the POH?

This was supposed to be fun, eh...