EDM 900 with Monroy Tanks

[glenv6]

Hi Group,

I am going to be putting a JPI EDM 900 into my '82 Mooney 201.  My plane has Monroy tanks, so I am wondering how the JPI is calibrated with those extra tanks.  Should I order the 2 tank option calibrated for 93 total gallons (mains + Monroy).

I haven't called JPI yet, I thought I would start here to find real life experience.

Also, apologies if this has been asked before, but I couldn't find anything specifics to my question.

 

My Thanks in advance!

Glen

Edited February 26, 2016 by glenv6

[KSMooniac]

Good question... you might need to ask JPI directly.  The Monroy STC doesn't include any changes in the OEM fuel indication system does it?  (I'm not familiar).  So, do your current gauges show full/32 gallons until the "extra" fuel burns down below that level?  Or do you have extra sending units added to the tanks so that you can indicate the extra fuel?

Having said that, they'll program the EDM to suit your particular aircraft.  In my case, I have an MT prop which deletes the yellow arc and they did that for my display.  I had to send a copy of the STC paperwork to them, though.

[glenv6]

32 minutes ago, KSMooniac said:

Good question... you might need to ask JPI directly.  The Monroy STC doesn't include any changes in the OEM fuel indication system does it?  (I'm not familiar).  So, do your current gauges show full/32 gallons until the "extra" fuel burns down below that level?  Or do you have extra sending units added to the tanks so that you can indicate the extra fuel?

Having said that, they'll program the EDM to suit your particular aircraft.  In my case, I have an MT prop which deletes the yellow arc and they did that for my display.  I had to send a copy of the STC paperwork to them, though.

Correct, the stock gauges read full until the extra fuel is burned off and the mains start going down.  The aux tanks do not have senders of their own.

I will be calling JPI on this, thanks!

[KSMooniac]

Since that is the case, I expect you'll just setup for a normal 2-tank (L&R) setup just like I did with my J and your EDM will be marked in the same fashion as mine as far as fuel quantity.  You can have it programmed, though, to set to 93 gallons as the full level for the totalizer function when you send in your data sheet and STC copy.  This is far more useful than the fuel quantity readings anyway.

[carusoam]

Great opportunity to improve on the knowledge of how much fuel is in the tanks.

See if this works....

Consider the new digital fuel float sensors combined with the JPI 900.

Scott Philiben, CEO of CIES Corporation, manufacturer of the floats. Scott.philiben@ciescorp.com. 541-977-1043.

Hope this gives some guidance for your challenge.

Best regards,

-a-

[glenv6]

24 minutes ago, KSMooniac said:

Since that is the case, I expect you'll just setup for a normal 2-tank (L&R) setup just like I did with my J and your EDM will be marked in the same fashion as mine as far as fuel quantity.  You can have it programmed, though, to set to 93 gallons as the full level for the totalizer function when you send in your data sheet and STC copy.  This is far more useful than the fuel quantity readings anyway.

That's pretty much what I was thinking.  

[glenv6]

3 minutes ago, carusoam said:

Great opportunity to improve on the knowledge of how much fuel is in the tanks.

See if this works....

Consider the new digital fuel float sensors combined with the JPI 900.

 

I just came across that option as I was searching for this info.  What's the cost to upgrade?

[carusoam]

I just updated Scott Philben's contact details in my previous post.

expect to replace four fuel level sensors.  Check with Scott for the details of price and integration.

Best regards,

-a-

[glenv6]

1 hour ago, carusoam said:

I just updated Scott Philben's contact details in my previous post.

expect to replace four fuel level sensors.  Check with Scott for the details of price and integration.

Best regards,

-a-

Thanks....  Do you know if those senders work with the little analog wing gauges?  I don't want to give those up, they are nice to have out on the wings and are accurate.

[tpapilot]

I was curious on the installation cost for the EDM900 with tank sensors, Did you get a quote on the installation?

IS it a 35 or 40 hr install or 60 to 70 hr install? 

 

[glenv6]

21 minutes ago, tpapilot said:

I was curious on the installation cost for the EDM900 with tank sensors, Did you get a quote on the installation?

IS it a 35 or 40 hr install or 60 to 70 hr install? 

 

I haven't received a quote yet, I am expecting to see it any day now....

[201er]

I don't think the EDM will be accurate with Monroy tanks unless there is a special way of calibrating it. The thing is that for the first 20 or so gallons you go through per side, the level barely goes down. The outboard tanks drain into the inboard and keep the level up pretty high. It depletes slower than normal tanks. Then toward the end once the outer tanks is empty, the inner tank drains at roughly a normal rate. There would either have to be a special custom algorithm to figure this or there would have to be a user input where you figure the actual fuel in tanks and calibrate the EDM that this level correlates to that number of gallons.

[carusoam]

Them funky digital sensors have an interesting level of flexibility with them.  Setting them up may require adding a gallon at a time for ultimate accuracy.  The website has good reading of how it works.  

I'm not sure if the Monroy would have a difference compared to the 100 gallon or 130 gallon Long Body tanks.  The float and sensor are probably moved to next section?  

As for the analog wing mounted gauges.  They are independent of the fuel instrumentation on the panel.  They are calibrated for accuracy on level ground. Nobody is going to give them up without a fight.

As for fuel used, with accuracy, I use the FT101.  The analog panel mount devices in my plane are more advisory in nature.  Or back-up to the FT101.

Some quirky things that make this a challenge...

- non-rectangular (irregular) shape of the tanks.

- the ability of the floats to go all the way to the top of the tank and settle all the way down at the bottom.

- up hill nature of the tank as they go out towards the wing tip.  Must be some air at the top where the tank vent is.

- other things that take up volume in the tanks, like Speed Brakes.

Mike, we need to do another side by side comparison to see where your J's fuel cap is located compared to the O.  

Some Mooneys use one float sensor per tank, like my C had.  The O has two sensors per tank to capture the uphill nature of the 100+ gallon tank.

Best regards,

-a-

[PTK]

Anthony, here's a question.

Say, for exampe, you have a J with with long range tanks and speed brakes. Full fuel let's say is 90 gal in round numbers. Given the aux tanks gravity drain into the mains, they (aux tanks) will empty first. Since you know their starting volume being 15 gal per side, can you not simply track the "fuel used" parameter sequentially per side? When the first 15 gal fuel used is reached switch to other side and track till 15 more gal are used. At this point you know the aux tans are empty. So now reset fuel flow computer to full fuel 64 gal and let the EDM do its thing as it normally would without aux tanks.

Do they drain linearly like that? IOW once 15 gal used is reached on one side all of it may not have come from aux tanks? 

[wpbarnar]

I wish they did drain in a linear fashion but unfortunately that is not the case.   The aux tanks on my K will still contain some fuel until the mains are at about 20 gals or less.    In the air,  it is almost impossible for me to determine the fuel remaining via the gauges if the main tank gauge reads 20 or greater.   All I know is I have the indicated volume plus a unknown amount in the aux.

Bill

[Godfather]

Does JPI allow you to make changes to the fuel level limits after the fact or do they lock it down being a primary unit?

[DonMuncy]

On ‎2‎/‎24‎/‎2016 at 9:16 AM, glenv6 said:

Hi Group,

I am going to be putting a JPI EDM 900 into my '83 Mooney 201.  My plane has Monroy tanks, so I am wondering how the JPI is calibrated with those extra tanks.  Should I order the 2 tank option calibrated for 93 total gallons (mains + Monroy).

I haven't called JPI yet, I thought I would start here to find real life experience.

Also, apologies if this has been asked before, but I couldn't find anything specifics to my question.

 

My Thanks in advance!

Glen

I would jump Jose and tell him to provide you a free fix.  

[KSMooniac]

2 hours ago, Godfather said:

Does JPI allow you to make changes to the fuel level limits after the fact or do they lock it down being a primary unit?

It is set by the factory according to POH/OEM and/or any pertinent STC limits.  You cannot change it in the field, but if you install Monroy tanks after you install an EDM, you can get them to update the settings in the unit.  Other parameters like oil pressure/temp, CHTs, fuel pressure, etc. are also programmed according to the POH data and you cannot change them.  You can set user alarms, though, at different values.  Particularly setting a CHT alarm at 400 instead of redline 475 is a good use of this feature.

[201er]

Even if you can add fuel one gallon at a time, it wouldn't help. When you fill up, you top the inboard then the outboard. But when you fly, the outboard slowly drains into the inboard. And no Peter, it doesn't keep the inboard full until the outboard is empty. It just keeps the inboard draining much slower than a standard tank but the level does go down slowly. It has to do with the dihedral angle, gravity, geometry, etc. Peter you're a math genius aren't you? Maybe you can figure it out.

Fuel flow and time end up being the best way to measure fuel with Monroy tanks. And the fact that you've got so much of it that you probably won't use it all by the time you get anywhere you want to go.

[carusoam]

There is no 'separate' outer tank. If there was, the fuel selector would have separate detents for them.  

Some Ks have a second fuel cap on each wing.  Using these, Less air gets trapped in the uphill section.

Interesting choice that is available.  The pilot can switch tanks based on time or on total fuel used.  I used time based on tradition.  But switching every 10 or 20 gallons used would make more sense to keep the load even through take-off, climb, and level flight.

Do you J guys have two float sensors per wing?

Best regards,

-a-

[M20F]

The only thing a fuel gauge tells you when you have a totalizer is you have a big leak.  

[201er]

4 minutes ago, M20F said:

The only thing a fuel gauge tells you when you have a totalizer is you have a big leak.  

And only after the tank is out of gas... all they care about is full and empty.

[M20F]

1 minute ago, 201er said:

And only after the tank is out of gas... all they care about is full and empty.

They are reasonably accurate.  Mine are good from full till about 8 gallons.  When they read 0 I have 4 gallons left.  I think it is important to have something to cross check the totalizer but if things are in the ball park, in totalizer I trust. 

[KSMooniac]

Yes, 2 floats/sending units per tank for the J.  

[PTK]

4 hours ago, 201er said:

Even if you can add fuel one gallon at a time, it wouldn't help. When you fill up, you top the inboard then the outboard. But when you fly, the outboard slowly drains into the inboard. And no Peter, it doesn't keep the inboard full until the outboard is empty. It just keeps the inboard draining much slower than a standard tank but the level does go down slowly. It has to do with the dihedral angle, gravity, geometry, etc. Peter you're a math genius aren't you? Maybe you can figure it out.

Fuel flow and time end up being the best way to measure fuel with Monroy tanks. And the fact that you've got so much of it that you probably won't use it all by the time you get anywhere you want to go.

Actually Mike, if I may humbly correct you, it has to do with the volumes in each tank and the size of the conduit from aux to main.

The dihedral enables the aux to gravity feed the main. The rate at which this happens has to do with volumes in each tank and varies accordingly.