What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Is this plan for the Fuel System Forward of FW OK?

Brantel

Brantel

Well Known Member
I have my FF transducer mounted and plan on doing the following to connect it to the Gascollator. ( I will use two straight fittings and make a U shaped piece of tubing to connect it up, see the red line)

Anyone see any issues with this?

2.jpg


The stock hose that Van's provides in the FWF kit seems to work perfectly with this 45? fitting.

DSCN7363.jpg



I want to connect/mount the primer solenoid on the other side of the gascollator with a steel male to male NPT fitting and a steel 1/4" to 1/8" reducing bushing.

DSCN7366.jpg


This is all comming out pretty close to my ANL and Shunt blocks but I think it will all work out OK.

DSCN7361.jpg
 
The primer solenoid - it appears to be connected to the outlet of the gascolator, how is fuel going to by pass it to arrive at the engine fuel system? Seems like the solenoid should be plumbed via a T.
 
David-aviator said:
The primer solenoid - it appears to be connected to the outlet of the gascolator, how is fuel going to by pass it to arrive at the engine fuel system? Seems like the solenoid should be plumbed via a T.
Click to expand...

There are actually three outlet ports on the gascollator..... Two big 1/4" NPT ones out both sides and one small 1/8" npt one at the top.

The top is plugged and the co-pilot side of the gascollator will be connected thru the U to the FF transducer then on to the E.M.F.P. and the other side I am planning to connect the primer solenoid then out to the primer lines.
 
Last edited:
Personally I think you're better off keeping the transducer in the cabin, this and the extra 'U' shape line will be just another heat sink for the fuel which increases the chances for vapor lock.
 
Brain,
This is the way i did mind, except i installed a 1/8" 90 fitting at the top of the gasolater and ran a SS flex hose to the primer sol which i mounted high above next to the right engine mount bolt. I also used SS tubing with steel fittings for the u shaped tubing. I justed wanted my flow trans to be filtered.
Brent
 
Walt said:
Personally I think you're better off keeping the transducer in the cabin, this and the extra 'U' shape line will be just another heat sink for the fuel which increases the chances for vapor lock.
Click to expand...

Walt,

Thought about this... The problem with this is that for the carb setup, I would want to add a filter to the line before the transducer and to keep things simple, I ditched that idea.

I have talked to several people who have the "U". Some say it is no problem, and one said he did have a problem with vapor lock but he put a piece of firesleeve over that "U" and all was well.

Thanks for the input!
 
Mine too

That's the way I did mine as well, and it all works real good. I agree that you should probably mount the primer solenoid remotely, and plumb it to the pressurized port to the gascolator. I used 1/8" soft copper and soldered fittings to plumb the primer system, as most certified applications I have seen use this method. Also, as has been posted and discussed here at great length, Use a piece of firesleeve on the u shaped bend to keep the heat off of the bend, and make sure that bend is as smooth as possible, and at the greatest radius that you can muster for the application. One more thing. At a fly in a couple of years ago, I saw a failure of the fuel hose fitting in an application exactly like yours (and mine) that could have been a crash and burner. The outlet hose 45 degree fitting at the transducer had seperated from the transducer housing due to fracture of the housing itself. Looks like yours is different. Mine is an aluminum casting, (Dynon), and is apparently weak at that point. Constant rocking of the engine kept working the thing until it just broke. Your transducer appears to be a machined aluminum block, and may take more stress, but my advice is to double adel the fuel line to the engine mount close to the transducer fitting, thereby reducing the stress on that fitting. I will try to get a photo to you and show you how I did it. I know of others that have done it that way, and I believe Bill Reppuci also secured his on his featherweight 9 after we talked about it on the phone a couple of years ago.
To be honest, on my current 9 project I am going to try to stay away from the loop and transducer fitting issue altogether, just to simplify the plumbing, and try to mount the transducer in the tunnel. But that said, most installations I have seen use the exact same approach you are proposing, and it appears to work just fine.
Hope this helps,
Chris
 
Yep the red cube is also a Dynon supplied sensor. Seems it is luck or bad luck of the draw on which one you will get when you order. (You decide on which is better or worse)

The Red Cube is actually a EI sensor.

It is really beefy and there is no way it is going to break. One big chunk of anodized billet aluminum.

I am going to ensure all the fuel line hoses are using steel fittings. The ones shown in the pics are for mockup as supplied by Vans.
 
Install a pre-filter and dump the gascolator...

Brantel said:
Walt,

Thought about this... The problem with this is that for the carb setup, I would want to add a filter to the line before the transducer and to keep things simple, I ditched that idea.

I have talked to several people who have the "U". Some say it is no problem, and one said he did have a problem with vapor lock but he put a piece of firesleeve over that "U" and all was well.

Thanks for the input!
Click to expand...

Actually it is recommended that you have a filter ahead of the little facet pump as it's inlet is not much bigger than the transducer and also succeptable to inlet debris. I always ran a 74 micron flow ezy filter in the line after the selector which protected both. When I swithched from carb to FI I dumped the gascolator and just stuck with the in line filter. IMHO the gascolator never really served any purpose after I installed the pre-filter (which was after I already had the gasco installed).
 
another idea for you

Hi Brian - just a thought...I'm working on a similar setup to yours (but with Andair Gascolator).

I was planning on following the EI directions (for certified airplanes) and plumbing the flow sensor between the engine driven fuel pump and the carb. I think that will allow me not to have the "U" shaped piece.

Note that they show drawings for firewall mounting (pg 19) or even suspending it between 2 flexible lines :eek: (pg 20). I think with the right support that would be fine (after all, these instructions are part of the STC package and have been reviewed by the FAA :cool:).... I may go that route (don't flame me).

I do have a much smaller "U" thingy going on between my gascolator and my primer solenoid. It is actually more of a curly-Q and it is made of the small copper tubing and it < 2 inches in length. I didn't firesleeve it and I'm hoping my tech inspector will give it the thumbs-up.
 
After looking at many installations, as well as variations in manufacturers techniques for installing the fuel flow meter....

I finally settled on installing a filter in each fuel line before they go into the fuel tank selector; and then the flow meter in the cabin between the aux pump and firewall mounted gascolator. Mine is a 6A and is mounted along the left sidewall.

I had heard numerous comments on accuracy of the flow meter in this type of installation. Turns out that mine is more accurate than I expected.

This eliminates U bends at the firewall, possible flexible lines and fire sleeves; and deciding whether to use aluminum or stainless steel on the engine side of the firewall.

My particular flow meter instructions actually showed an RV install with the flow sensor after the aux pump as an option.

I'm leaving the gascolator, since this was installed prior to the fuel sender install, and it also has the top fitting to go to the primer solenoid.

L.Adamson --- RV6A (flying)
 
So assume I am going forward with my "U", whats the least expensive way to seal the ends of the firesleeve?

Also, what type/specs of stainless should I purchase for the "U"?
 
Last edited:
Brian,
I'm glad you're going forward with the installation as is. It will work just fine. I have made 4 installations where I've attached the fuel transducer directly to the gascolator and also supported it with it's own attaching angle to the firewall. This was contrary to flo scans recommendation for 6 inches of straight tube before and after the unit. 30 gal. fill ups are accurate to less than .5 gals. The only vapor locking problems I've experienced are, waiting for my poor formation mates that have fuel injection to hot start there planes.:rolleyes:
I just use safety wire to secure the ends of the firesleeve.
Best regards,
 
You must log in or register to reply here.
Back
Top