JPI Fuel Flow Transducer Installation

M

Morris

New member
I am planning on installing a JPI Engine Monitor on my 7GCBC and am looking to find out how others have installed the fuel flow transducer between the filter and carb. My AI looked at it and said "not much room, figure it out and let me know".
I know I'm not the first to have ever done this, so I thought it best ask first and find out what works from someone that has done it already.
Best regards
Morris
 
Glad to hear your putting one in. I'm putting in a EDM-700 in my 7GCBC but without fuel flow. I just bought this airplane and couldn't live without one as my other plane is a 206 with the 700 wf fuel flow. I thought I was the only one in the world with a JPI in a GCBC as I could not find any info on anyone else having one. Where are you putting it? I had a blank space on the bottom row but found that I couldn't get my fingers on the buttons.
Sorry I cant help with the transducer, but let me know how it turns out in case I decide to add it later. I didnt feel I needed the FF in this plane (or maybe it was a money issue) :)
 
How old is the plane?
(determines where the Gascolator is)

In newer ones we had special lines made to hold the FF sender for the JPI 930. I assume the installation would be the same for the 700. It was certainly tight and had a few iterations to minimize the chance of cracking fittings.
 
My 7GCBC is a 1973 with the old style fuel valve and dual exhaust.
The fuel filter is directly behind the Carb inlet. The JPI EDM-700 uses a Flowscan transducer. The high flow Transducer for gravity feed fuel systems has 1/4 npt inlet and outlet. The Strainer and Carb are 3/8 npt. or -6 line. For those not familiar with a fuel flow transducer, it is a small turbine that spins as fuel passes. A light beam is broken by the turbine; the fuel totalizer counts these pulses to measure fuel flow. The body is aluminum so you do not want it carry unsupported line loads such as mounting it directly on the carb or filter and hanging a line off of it. You also have to shield it from heat with fire sleeve. You also have to have a straight line in and out to reduce turbulence in the turbine.
Because the left hand exhaust is in the way I cannot exit the fuel filter to the left and loop around to the carb inlet. If I go straight forward and loop back to the carb the lines would have to be supported by the engine. If I go right the lines would run behind the engine, then loop 180 deg. back across the engine, then 180 deg. to the carb inlet. Minimum bend radius for 156 Stratoflex -6 line is 2.5". This adds about 3+ feet of fuel line. I like simple, bullet proof solutions, but I don't see it here.
Regards
Morris
 
Hi, What about installing it between the fuel shutoff valve and the gascolater? I know it would be desireable to keep the additonal fuel connections out of the cabin, but it may offer more room and better mounting options. I really don't know how long this line is as my Scout project is at the airport, just guessing. This isn't an orginal idea of mine, saw it used on Supercub.org where they mounted the transducer in the side wall of a PA18. Tim
 
Yes, i think you are not going to get 5 pounds of $%#& into that 3 pound box you got there. It was tight on the new ones where the Gascolator is way over on the in left side.
 
I looked inside and I agree the inside looks like a good option. One way would require moving the fuel filter to the right. The existing aluminum line with the proper fitting could hook up to the inlet to the fuel transducer. Then fabricate a line from the outlet of the transducer to the inlet of the fuel filter. On Flowscan's web site they like a straight line both in and out of the transducer for several inches to straighten the flow, their installation show that rigid lines can be used. With a new line from filter to carb and you’re done.
But two possible problems. The STC shows the unit installed in a straight section of flexible line that is secured to the firewall or engine mount up to 8" away from the transducer. The transducer is basically hanging in the middle and wrapped in fire sleeve, and then moving the fuel filter / gascollator.
The inside looks like a better installation, away from heat, vibration, and can be inspected. But can I get anyone to buy it off?? :roll:
Any AI’s willing to offer an opinion?
Regards
Morris
 
I installed one on a customer's 7GCBC several months ago, and the solution I came up with is neat and works well. I ran the fuel supply hose from the gascolator around the right side of the carb and looped it to the front. The transducer sits in front of the carb supported by a brace, and the hose exiting it continues the loop back to the carb. It's neater than it sounds. I took digital pictures of the installation, but they're at the shop. If you want to see them I can post them Monday after work.

Hag
 
Hag
Thank you for your post. I would very much like to see your pictures. If you cannot post them on the forum please email them to cgp@nwlink.com

Best regards
Morris
 
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