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Fitting FT-60 After Fuel Servo - Hose Questions?

shuttle

shuttle

Well Known Member
Nick Nafsinger's broken fuel line in IMC has got me thinking about my FT-60 fuel flow sensor installation. It's not yet complete but I have installed it according to the manufacturer's instructions in the preferred location between the Fuel Servo and the Fuel Divider. It is on a TMX-IO-360-M1B which limits the positioning! There's only one place for it! I spoke with the manufacturer and they were happy with a 90 degree elbow fitted on the outlet side of the FT-60

The bit I don't like about the install is the shape the outlet hose has to take up to get to the grommet in the inter-cylinder baffle. You can see this on the left of the photo below. The cause of this is the length of the inlet hose. The hose is the shortest that could be made and has -4 flared hose ends each end. The FT-60 (under the firesleeve in the photo) has -4 flared-to-1/4NPT straight steel adapters on both ports.

Is that bent shape taken up by the FT-60 outlet hose going to be ok? I don't want it failing!

If not, how can I best make the inlet hose shorter? (It's only just 4 inches as it is.)

Are 1/4NPT hose ends available for a -4 hose that would remove the need for the flared-to-NPT adapter on the inlet side and hopefully shorten the inlet hose run? If so, would that be an improvement or a step backwards in reliability?

Thanks in advance for any thoughts and advice.

2i51rc.jpg
 
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Steve, in the general discussion forum there is a thread about Flowscan location. It might be worth you reading even though you have a different flow sensor. I had similar dramas to what you are having now. I was reccomended to put my Flowscan sensor in the position you have yours. I was not at all happy with the result, as obviously you arn't. I ended up putting mine in the tunnel, from where I had removed it. I hope this may be of some help.:)
 
Phil (PIN37), Thanks.

I've just read this thread which you participated in: http://www.vansairforce.com/community/showthread.php?t=55386&highlight=flowscan

Yep, sounds like you've been where I am currently at. I see that you rejected this furthest downstream position and also the next one back between the engine-driven pump and the fuel servo.

I'm pretty sure that some folks have managed a successful install where I have it right now. I'm hoping one of them will come forward and say what they did differently to me.

I am loath to spend anymore money speculatively on new hoses to try things out (e.g. moving the FT-60 before the fuel servo).

If I don't hear any suitable advice I suspect I'll be following you by moving the sensor back into the tunnel in the cabin.

Thanks,
 
I'd move it!!!

Hi Steve,

I have mine (FT-60, red cube) mounted securely on the firewall (engine side) between the AFP electric pump and the engine driven pump. The cube is on a bolted to a bracket that in turn is bolted to the firewall (to maintain the correct orientation - wires pointing up). The pipe from the electric pump is aluminum; both ends are fixed (on the pump at the proximal end and on the cube at the other. The flex pipe to the EDP comes off the distal side of the cube. The numbers that come out on the Dynon screen seem consistent and sensible.

I wouldn't rely solely on the derived number from fuel flow measurement to determine how much gas I had left.

The location is I have used is given in the instructions:

"Possible Transducer Placement Locations:

1.Between the auxiliary electric boost pump and the engines mechanical fuel pump.
2. Between fuel injection servo and the distribution block.
3. Between the Engine driven pump and the Carburetor."

To me, your current location and installation look distinctly dodgy!!! I'd have been surprised if my (very picky, but very reasonably so) inspector would approve......

HTH??

Chris
 
Think I'm going to move it too.

Hi Chris,
Thanks for taking the time to respond.

Yes, I agree, with the bend in the outlet hose, it is not good. I didn't like it as soon as I was able to connect up the hoses I bought. The shortest possible inlet hose was still too long. If the outlet hose had come out with a straight run to that intercylinder baffle grommet I feel it would have been fine. That is what I would like to achieve. I suspect however that I will not be able to do so. Safety is my only goal at this stage. Fuel flow numbers for fuel pouring out of a failed hose will be of little use to me :(

With two people now (yourself and Phil) both confirming my own feelings I'll almost certainly move it.

My firewall setup is exactly as per Van's plans for the fuel line passthrough (which I feel is closer than I would like to the starter contactor). I am not convinced I can that easily adapt your setup to my firewall. In the RV-7 horizontal induction Van's scheme the fuel line FW passthrough is relatively close to the EDP. This is good from a "keeping fuel cool" perspective but leaves little option for introducing a FF sensor into that section of hose. I don't really want to take any of the fuel line nearer to the exhaust. All the close-by free space on the FW is right there in the bottom-centre just above the exhaust.

Going back to a cabin-side install is looking increasingly attractive.

I've seen ao.frog's EDP-to-fuel servo line FF sensor install but spending yet more money on more hoses on a solution that I may still not be happy with is putting me off.

Thanks again,
 
elbows

Steve,
I have just installed a Flight Data Systems Fuel Computer that included a RED cube install on a carb'd 0-360. Not exactly your setup but I faced similar issues with fittings. I installed mine between the mechanical pump and the carb.

Have you tried installing the cube perpendicular to the fuel flow and use elbows on each end, one pointing horizontal to the controller and one pointed vertical to divider. That lengthens the hose from the controller and could help alignment with the baffling grommet.
Just a thought. Good Luck.
 
Are 1/4NPT hose ends available for a -4 hose that would remove the need for the flared-to-NPT adapter on the inlet side and hopefully shorten the inlet hose run? If so, would that be an improvement or a step backwards in reliability?
Click to expand...

NPT swivels are common in hydraulic hose product lines.
 
Bob Martin said:
Steve,
I have just installed a Flight Data Systems Fuel Computer that included a RED cube install on a carb'd 0-360. Not exactly your setup but I faced similar issues with fittings. I installed mine between the mechanical pump and the carb.
Click to expand...
Bob,
Do you have a picture of your setup, with the install of the red cube. I'm planning on replacing my flowscan and doing some repositioning of the transducer in my carb'd install.
 
yes

scard said:
Bob,
Do you have a picture of your setup, with the install of the red cube. I'm planning on replacing my flowscan and doing some repositioning of the transducer in my carb'd install.
Click to expand...

Yes I do have pictures, but not here at work. I'll send you some this evening.
But after racking my head about where to install it and what would be the best orientation, I ended up with a slow bend from the mech fuel pump to the carb.
Mechanical pump 90 degree ell pointing down and rearward in a 45 degree angle. I put a 45 degree AN fitting on the inlet side of the cube and a straight fitting on the outlet side going to the carb. Carb has a 90 degree ell too.
Pretty straight forward but a picture is worth a 1000 words.
 
Bob/Dan, Thank you for your responses.

Bob,
I think I understand what you are saying - basically to have the sensor inlet/outlet oriented vertically rather than horizontally as I have today.
I agree that this would probably solve the grommet alignment issue but I don't think this complies with the FT-60 installation instructions as it would require a 90 degree elbow on the inlet port. Thanks all the same.

Dan,
I figured NPT hose ends ought to be available. The FT-60 has female 1/4NPT ports so I'd need male 1/4NPT steel hose ends for -4 hose. I've just looked on the www.earls.co.uk website here in the UK. They do indeed offer NPT hose ends but not in steel and not in that NPT size/hose size combination I'd need. They offer 1/4NPT for -6 hose and 1/8NPT for -4 hose. I'd need a 1/4NPT hose end for -4 hose.

Is that 1/4NPT steel hose end for -4 hose likely to be found anywhere?

Thanks & Regards,
Steve
 
not quite

shuttle said:
Bob/Dan, Thank you for your responses.

Bob,
I think I understand what you are saying - basically to have the sensor inlet/outlet oriented vertically rather than horizontally as I have today.
I agree that this would probably solve the grommet alignment issue but I don't think this complies with the FT-60 installation instructions as it would require a 90 degree elbow on the inlet port. Thanks all the same.

Thanks & Regards,
Steve
Click to expand...

Steve,
inlet/outlet not vertical, but horizontal....and perpendicular to what you have now. or another way to say it would be to rotate it 90 degrees from what you have now. It takes a minute to get your head around it. There is another thread on this same subject where an employee of EI, the manufacturer of the Red Cube says it is ok to have 90 degree ells on either side or both and I have confirmed this with other EI reps. Apparently this is a problem for the FlowScan units, but not the Cube. It may not even be physically possible, I can't tell from the picture, but worth considering.
Again, just more ideas and my .02 cents.
 
Thanks Again, Dan & Bob, much appreciated.

Dan,
Yes, true. Male 1/4NPT to -6 hose to -4 flare. Thanks,

Bob,
I get it now. You're suggesting the inlet/outlet axis be aligned parallel to the a/c centre line (fore/aft orientation) with 90 degree fittings both ends, the outlet one pointing up and the inlet one pointing a/c left.

I exchanged emails with EI too not that long ago. In that conversation EI said that 90 deg elbows on the input side were a No-No. They said that Straight In/90 Out or 45 In/45 Out were ok. This clearly conflicts with what you say you were told. I will take a look to see if that might work in the 3D space I have. Thanks.

Steve
 
Steve,
Working from the home computer with access to saved files....I love catalogs.

Steel hose ends would be found in the industrial world. The classic Aeroquip industrial hose and fittings catalog is available here:

http://www.youblisher.com/files/publications/1/3094/pdf.pdf

Re steel NPT hose ends: A quick scan says FC234 hose is rated for gasoline and fire resistance, but it is intended for use with reusable fittings and they are rather long (a little less than 2'). Don't know if that will allow a short enough assembly, even after eliminating the AN816(s).
 
Dan,
Thanks! That was really spooky! Don't normally bother but I just completed an online survey on the Eaton/Aeroquip website saying how dreadful their navigation/search facilities were. I'd just failed to find exactly the file you supplied. I've saved it on my pc too now.

I just had another idea! My fuel servo (a Precision Airmotive Silver Hawk EX-5VA1) has a 90 degree elbow fitting on the top onto which this hose in question is fitted. If I were to spin this 90deg fitting to point forward and use a hose with 90deg fitting as well it might buy me another 1/2 inch.

This does all sound like it's getting ever so complicated though :(

It did cross my mind that I could remove the fitting on the Silver Hawk altogether and contemplate a hose that went straight into the servo body but I don't think that would really be sensible for maintenance reasons - I'd probably have to remove the servo just to install/deinstall the hose. Also, it is very tight for space on top of the servo.

Thanks for your assistance, Dan. I will look into the NPT hose end option for the FF sensor end - the 412-4-4S p/n on page 190 looks like it might do what I want (or even the 412-4-4B as I think brass fitting are preferred by EI over steel).

Regards,
 
(or even the 412-4-4B as I think brass fitting are preferred by EI over steel).
Click to expand...

Maybe so, but remember the rules of fatigue are the same for brass and aluminum....no knee in the S-N curve, so be sure the load amplitude or number of load cycles is low. At 10^7 cycles the endurance limit for brass is less than 30% of UTS.

Guess my preference ;)
 
I also read Nick's horrifying but awesome handling in IMC and that prompted me to yet again revisit the location of my transducer.
First about your installation, I would also add my voice to others that it does not look that safe. Too short of a run with the bend on the line makes me uncomfortable about it.
Mine which I started with the floscan and just recently replaced it with the red cube has been installed in the tunnel with more accuracy then I had ever expected. I have looked for a possible place (IO-360-M1B) to install it in the recommended place and no reasonable location seems to be there and the risk of a failure seems so much higher with more danger involved. Here are the things I don't like FWF installation: Heat, vibration, taking longer to detect failure, complex installation.

So, mine is still in the tunnel till I am convinced otherwise. I am using it with the GRT EIS and its accuracy has been about 0.2 to 0.3 a gallon in every 20-30 gallon fill up. That is about 1% of error.
 
DanH said:
Steve,
Working from the home computer with access to saved files....I love catalogs.

Steel hose ends would be found in the industrial world. The classic Aeroquip industrial hose and fittings catalog is available here:

http://www.youblisher.com/files/publications/1/3094/pdf.pdf

Re steel NPT hose ends: A quick scan says FC234 hose is rated for gasoline and fire resistance, but it is intended for use with reusable fittings and they are rather long (a little less than 2'). Don't know if that will allow a short enough assembly, even after eliminating the AN816(s).
Click to expand...

Just stumbled on this through a Google search of all things, after a long tiresome search for information on AN fittings. Eaton's site is awful. I never did find a direct to the catalog, which is now safely stored as a pdf on this machine :) Thanks, Dan!
 
Thanks for your comments, Mehrdad,

I am going to have one last try. Earl's are able to source a steel 1/4NPT male hose end and make up a hose for me. Eliminating the AN816-4-4 may shorten things enough to allow the vertical hose to line up with the grommet. If I'm not happy with the result I'll abandon the FWF install and move the FF sensor into the cabin.

Thanks everyone for your assistance.
 
Lars said:
I never did find a direct to the catalog, which is now safely stored as a pdf on this machine :) Thanks, Dan!
Click to expand...

Posted that one because it has the NPT and JIC flare fittings selection from the hydraulics line. Same catalog, new version:

http://hydraulics.eaton.com/products/fluid_conveyance_aeroquip.htm

This is the popular aerospace fuel hose with integral brown silicone firesleeve:

http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&dID=247006

The Weatherhead fittings catalog can be useful:

http://hydraulics.eaton.com/products/fluid_conveyance_weatherhead.htm

See catalog page 306; you'll recognize the standard 90 degree fuel pump fitting sold by ACS and others.....but did you know it also comes in extended lengths (page 307) and run T's (page 311)?
 
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Why install between servo and spider

Why are folks choosing to use this spot.

I've installed two floscans on two different RV's with the sensor bolted firmly to the firewall (hot side) after the boost pump and well before the mechanical.

This is a mechanically sound location that is easy to firesleeve. You can use hard line up the flowscan and a flex hose downstream.

No problems with the flow readings in this location.

Just seems like a more convenient and sound spot.
 
DanH said:
Posted that one because it has the NPT and JIC flare fittings selection from the hydraulics line. Same catalog, new version:

http://hydraulics.eaton.com/products/fluid_conveyance_aeroquip.htm

This is the popular aerospace fuel hose with integral brown silicone firesleeve:

http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&dID=247006

The Weatherhead fittings catalog can be useful:

http://hydraulics.eaton.com/products/fluid_conveyance_weatherhead.htm

See catalog page 306; you'll recognize the standard 90 degree fuel pump fitting sold by ACS and others.....but did you know it also comes in extended lengths (page 307) and run T's (page 311)?
Click to expand...

Thanks for the links, Dan. I have an older version of the Weatherhead catalog on my shelf, as well as an Aeroquip performance products catalog. Handy stuff.

As it turns out we have bins of JIC fittings (made by Parker) similar to the ones on page 306 in various sizes. The ones we have here are all plated steel. We even have Viton o-rings for them, since some of the fluids we use here aren't compatible with nitrile.

BUT... I guess I have been indoctrinated with the "always use AN, not JIC" on an aircraft. The fitting I was looking for, and which led me on my search, was a -4AN male to -4 (7/16-20) SAE ORB fitting in stainless steel, to use on the back side of my P/A injector servo. Currently there is a 90? version of that fitting installed on the front, but the routing doesn't work very well for my vertical draft setup. Have not found a source for AN x SAE ORB fittings though, other than possibly contacting P/A (which I have not done yet).

If I could be convinced that JIC is ok, we have the exact fitting I need (albeit not stainless) on the shelf here at work.
 
dedgemon said:
Why are folks choosing to use this spot.

I've installed two floscans on two different RV's with the sensor bolted firmly to the firewall (hot side) after the boost pump and well before the mechanical.

This is a mechanically sound location that is easy to firesleeve. You can use hard line up the flowscan and a flex hose downstream.

No problems with the flow readings in this location.

Just seems like a more convenient and sound spot.
Click to expand...

There have been some threads on this topic in the past. Two things come to mind:

1) Some flow transducers apparently have enough pressure drop through them that there was a concern about pulling fuel (with the mechanical pump) through the device leading to vapor lock.

2) Pulsing from the mechanical pump (pulling or pushing) could confuse the transducer. Placing the device downstream of the fuel pump servo would eliminate that.

I have no personal experience (plane not flying yet). Just reporting what I remember from reading in older threads. And field experience described by several posters contradicts what I wrote.
 
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Lars said:
If I could be convinced that JIC is ok, we have the exact fitting I need (albeit not stainless) on the shelf here at work.
Click to expand...

Is there an optical comparator or other magnification available? Put your current fitting (and a new Parker) under the lens and examine the thread root. I suspect your current -4 servo fitting is JIC UNF rather than UNJF.

 
DanH said:
Is there an optical comparator or other magnification available? Put your current fitting (and a new Parker) under the lens and examine the thread root. I suspect your current -4 servo fitting is JIC UNF rather than UNJF.

Click to expand...

I finally got around to removing the 90? fitting from the front of the servo last night. Lo and behold it wasn't an SAE ORB x 37? fitting at all. It turned out to be AN (and was marked as such), but it was a stainless steel AN833 fitting with nut, under which P/A had added an o-ring. The color was blue, which according to my Parker o-ring book means that it's fluorosilicone. I threaded my straight JIC fitting into the port, it fit nicely (not surprisingly). Now I'm wondering if SAE ORB x 37? AN fittings even exist.
 
I had the cowl off and was looking again for options and was wondering if the red cube can be mounted directly to the throttle body or even with a very short hose, perhaps 2" long? This is the in-port of the red cube will be connected to the 90? fitting of at the bottom of the throttle body. It seems one can easily fabricate a mount that will utilized the bottom bolts of the throttle body (both front and back) to hold the Red cube in place and then the out put line will go much easier to the divider?

Any thoughts on that? I am thinking there must be some thing wrong with the idea as no one else seems to have tried it.
 
I installed my red cube in the same place after the servo. I used two 90 degree Weatherhead brass elbows in series on the output of the cube to offset the hose connection. It worked out nice with no hose bends...fuel flow is not erractic and seems accurate.
 
Here's mine...

I have installed it beetween the mecanical fuelpump and the Silverhawk injector. (you can see it's wire sticking up from the firesleeve)
No problems so far (140 hrs) and stable FF-readings.

This was the only place I could find which allowed straight lines into and out from the cube.

The cube is hanging on the fuelline and both the line and the cube is covered up with firesleeve.
(All edges was covered up with high temp RVT after this pic was taken.)

The fuelline is clamped to the induction-tube for the front left cylinder so it won't chafe on the induction tube. (hard to see on the pic, but you can see the clamp itself)

I've also installed heatshields where the fuel line passes the exhaust tubes.

 
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I like the servo downstream from the servo,

and this location mimics the one used by the factory on our last Mooney ('91 Bravo). It provides a consistent non pulsing flow, and is downstream of all pumps. One concern I have is the impact of engine vibration on the life of the Flowscan, but we had no problems with the hard mounted location on the Mooney.

The short stainless loop from the transducer to the divider is heavy wall tubing with all steel fittings. It's securely mounted with no relative motion at either end of the SS line. This location provides a long straight inlet flow to the Flowscan, and it's on the cool side of the engine (at least in flight). I know the transducer is supposed to be mounted with the wires pointing straight up, but this position seems sufficient to clear any vapor through the Flowscan just fine.

Working well so far, but only 90 hours...:)

IMG_3572.jpg


IMG_3571.jpg
 
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Lars said:
I finally got around to removing the 90? fitting from the front of the servo last night. Lo and behold it wasn't an SAE ORB x 37? fitting at all. It turned out to be ....a stainless steel AN833 fitting with nut, under which P/A had added an o-ring.....I threaded my straight JIC fitting into the port, it fit nicely (not surprisingly).
Click to expand...

Cool. Somewhere I heard of SAE ports set up to use AN bulkhead fittings as an O-ring straight fitting, which I think just means boring deeper. Same thread pitch. Did they cut off the make flare tip or bore deeper?

Now I'm wondering if SAE ORB x 37? AN fittings even exist.
Click to expand...

http://www.parker.com/portal/site/P...TUBE+TO+STRAIGHT+THREAD+UNF+-SS&Wtky=FITTINGS
 
DanH said:
Cool. Somewhere I heard of SAE ports set up to use AN bulkhead fittings as an O-ring straight fitting, which I think just means boring deeper. Same thread pitch. Did they cut off the make flare tip or bore deeper?



http://www.parker.com/portal/site/P...TUBE+TO+STRAIGHT+THREAD+UNF+-SS&Wtky=FITTINGS
Click to expand...

The fitting was intact. The hole in the servo is bored quite deep, and based on a quick glance appears to have a 37? taper at the bottom. Not that that would have done any good unless the orientation of the bulkhead fitting was irrelevant (as it could be I suppose if one were to use an AN832). With the nut & o-ring added, the fitting in my servo effectively became a 4-C5OX-SS.

The Parker Triple-Lok fittings are nice parts to be sure, in fact it's a steel 4-F5OX fitting I test-fitted into the servo. But according to my Parker catalog at work, they are JIC. They make no mention of meeting the SAE AN or AS spec. But I'm increasingly convinced that it's unimportant for this application. The local Parker fitting supplier has the desired 4-F5OX-SS fitting in stock. Will be picking one up tomorrow.
 
Lars said:
The Parker Triple-Lok fittings are nice parts to be sure, in fact it's a steel 4-F5OX fitting I test-fitted into the servo. But according to my Parker catalog at work, they are JIC. They make no mention of meeting the SAE AN or AS spec. But I'm increasingly convinced that it's unimportant for this application. The local Parker fitting supplier has the desired 4-F5OX-SS fitting in stock. Will be picking one up tomorrow.
Click to expand...

Pretty sure we're all using fuel pump fittings with JIC UNF threads.
 
1/4NPT Hose End

Got my new shorter hose with the integral 1/4NPT steel hose end at one end.
Seems to do the trick. Installation now looks a lot better. No tight bend anymore in the outlet hose.
Photos below.

Would appreciate any new comments?

ruxsm8.jpg


2n9ixs8.jpg


s3iptx.jpg


18ngpl.jpg


zmbl9l.jpg
 
fitting

Lars---if the fitting is forged, it should be fine.
Tom



Lars said:
Thanks for the links, Dan. I have an older version of the Weatherhead catalog on my shelf, as well as an Aeroquip performance products catalog. Handy stuff.

As it turns out we have bins of JIC fittings (made by Parker) similar to the ones on page 306 in various sizes. The ones we have here are all plated steel. We even have Viton o-rings for them, since some of the fluids we use here aren't compatible with nitrile.

BUT... I guess I have been indoctrinated with the "always use AN, not JIC" on an aircraft. The fitting I was looking for, and which led me on my search, was a -4AN male to -4 (7/16-20) SAE ORB fitting in stainless steel, to use on the back side of my P/A injector servo. Currently there is a 90? version of that fitting installed on the front, but the routing doesn't work very well for my vertical draft setup. Have not found a source for AN x SAE ORB fittings though, other than possibly contacting P/A (which I have not done yet).

If I could be convinced that JIC is ok, we have the exact fitting I need (albeit not stainless) on the shelf here at work.
Click to expand...
 
TS Flightlines said:
Lars---if the fitting is forged, it should be fine.
Tom
Click to expand...

Thanks, Tom.

On an RV-related note, if you are going to keep weighing in on all this stuff, it's time for you to step up to the plate and get started on that RV that you know you want :D
 
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