Red cube plumbing

jimgreen · #1 10-27-2009, 06:34 PM

I have an IO360 from Aerosport and am a bit puzzled by the flow transducer from EI. Looking at the EI red cube it seems to have inlet and outlet threaded for 6d fittings(3/8") . The outlet fitting from FI and the inlet to the spider are 4d fittings. Is this correct? Seems I'll need an adapter on both sides of the transducer. Are adapter fittings available in steel? If this is the normal situation I'm surprised that noone has mentioned it.

EricB · #2 10-27-2009, 08:03 PM

Hi Jim,

I assume you have the FT-60 model of the Red Cube. This is the unit I have on a Superior I0-360. It has a 1/4 inch NPT.

You will need an AN-816 (NPT to flared) fitting. If you want to use this on the fuel line from the FI to divider (spider) line which is 1/4" on my engine then you would use an AN816-4-4. If you use it on the mechanical fuel pump to FI line which is 3/8" then you would use an AN816-6. They area available in steel, designated by the absence of 'A' after the size. I own 2 of each , had to learn the hard way.

You will need an adapter on each side of the cube.

See the chart in the link below.

http://www.aircraftspruce.com/catalog/hapages/an816.php

Hope this helps.

Eric
RV-7 FWF/Cowling

jimgreen · #3 10-28-2009, 12:04 AM

Thanks Eric. I was forgetting that the usual application is with 3/8". I guess I need the AN912 NPT reducers to run the 1/4" hose to the cube. I didn't know those NPT reducers existed.

RVbySDI · #4 10-28-2009, 12:09 PM

I posted on another thread concerning the mounting of the FT-60 sensor. Can anyone comment on where they have mounted theirs? I had plans for mounting them in the center section but they are taller than the cover so I am not sure where to mount them. Any info would be appreciated.

shuttle · #5 10-28-2009, 02:50 PM

Jim,
No, I do not believe you need a reducer (been there myself).

The AN816-4-4 (steel fitting) that Eric quoted has 1/4 NPT to 1/4 flared hose fitting,
vs the more common AN816-4 which is 1/8 NPT to 1/4 flared hose fitting.

Steve

sf3543 · #6 10-28-2009, 02:57 PM

I mounted mine on the firewall, in the hose section between the fuel pump and the servo. There are restrictions as to how high above the servo it should be mounted, when the plane is level, but those are listed in the directions.
Mine was very accurate once dialed in.

Rick6a · #7 10-28-2009, 03:11 PM

Quote:

Originally Posted by RVbySDI

...Can anyone comment on where they have mounted theirs? I had plans for mounting them in the center section but they are taller than the cover so I am not sure where to mount them. Any info would be appreciated.

You don't say if your engine is fuel injected or not. If it is fuel injected, this thread has some good information and installation photos of the red cube:

http://www.vansairforce.com/communit...low+transducer

Note: EI has some very good installation instructions for use with their red cube (linked at post #23) and my installation (post #13) is consistent with their suggestions.

jimgreen · #8 10-28-2009, 03:15 PM

First off, I'm no expert! There is lots in the archives on this topic. The requirements of this transducer get mixed up with those for the floscan.
According to Mike at EI, these transducers are pretty tolerant regarding mount position. I understand that if you are fuel injected they prefer between the Servo and the spider to eliminate pressure pulses. Many people have put it in that line where it runs vertically up the back of the engine( my planned instal) or on top of the engine just before the spider. This has an advantage for instals with return lines too, since you're only metering fuel that goes into the cylinders.
Mike reckons the requirement of 6" straight run before the cube is desirable but not necessary. He did think it important not to have the fuel descending through the unit.(as per the data sheet)
He also commented that these units prefer to have fuel pushed through them rather than sucked, so after the pump(s) is preferable.

jimgreen · #9 10-28-2009, 03:21 PM

Quote:

Originally Posted by shuttle

Jim,
No, I do not believe you need a reducer (been there myself).

The AN816-4-4 (steel fitting) that Eric quoted has 1/4 NPT to 1/4 flared hose fitting,
vs the more common AN816-4 which is 1/8 NPT to 1/4 flared hose fitting.

Steve

Thanks Steve. I keep coming across fitting types that I've never heard of!

shuttle · #10 10-28-2009, 04:12 PM

Jim,
I have the EI FT-60 Red Cube too but my engine (TMX-IO360-M1B) sounds like it has a different configuration to your's. My fuel servo-to-distributor hose, that I need to interrupt to install the cube, is at the front of my engine.

I too have spoken to EI as I could not comply with the install instructions that came with my AF-3500, specifically the 5 inches of straight flexihose in and out of the cube. EI Support advised that is was acceptable to have angled fitting on the cube. Straight in is best but 45 in, 45 out would be better than straight in, 90 out. Never the less, I think I'm going to have to go straight in, 90 out.

The reason for mentioning this is that the AN816-4-4 (straight) and AN822-4-4 (90 degree) both provide for 1/4 NPT-to-1/4 flared tube fitting. However, if you need to use a 45 degree fitting it appears that there is no such thing as an AN823-4-4 (from AircraftSpruce anyway) so you WOULD need a 1/4-to-1/8 NPT reducer to use with an AN823-4.

Whether this info is of any use to you I don't know but figured it worth posting what I found out in case it helps any others in the future.

Steve