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wing root filters

Rv8bill

Member
Curious to know how many folks are installing the performance flow filters in the RV8 wing roots. My wings are not yet installed but it looks like the fuel line coming out of the wing shares a common centerline with the same line going into the fuselage. Does this present a problem when locating the filter in the wing root? How much space is there to work with when installing the filters here? Looking for some insight. Thanks in advance for the input.
 
Wing root filters

I installed a wing root fuel filter on each wing. I used Earl's racing filters with a stainless steel filter. The only downside is you will need to have the fuel level below the filter when you disassemble them for cleaning. I sump my tanks at annual, so I do it at the same time. They have worked great for me. I am carbureted, so I do not need the really fine fuel filters that an injection system requires. It keeps the fuel filter cleaning mess out of the cockpit and is very easy to access. I would do it again if I built another RV.
 
One filter

Have an EFII filter in the fuselage after the fuel valve and before the EFII boost pump.

Very very tight in the wing root of the 8.

Don
 
Always an option to put one filter on each wing tank line. My caution is to take all possible steps to eliminate 90 degree fittings in your install.

Carl
 
Search for Tom of TS Flightlines here. He provides a complete kit that mounts the filters on the side of the Fuse with a shut-off valve that is normally wired open, but can be closed for filter cleaning. Depending on where you are in your build, he can also provide all the plumbing downstream of the filters to the valve and the fuel pump and to the firewall.

Mine is on order.
 
I installed a wing root fuel filter on each wing. I used Earl's racing filters with a stainless steel filter. The only downside is you will need to have the fuel level below the filter when you disassemble them for cleaning. I sump my tanks at annual, so I do it at the same time. They have worked great for me. I am carbureted, so I do not need the really fine fuel filters that an injection system requires. It keeps the fuel filter cleaning mess out of the cockpit and is very easy to access. I would do it again if I built another RV.

I put Summit Racing 40 micron SS mesh filters in the root of both wings on my 7. Plan on doing the same on my 8 when I get that far. As long as you seal the vent and your cap seals properly, when you open the filter for inspection/cleaning only a few drops of fuel will leak even if the tank is full. I have been doing this for my inspections the last 4 years with no issues. Just remember to open the vent when you are done!
 
IL4 Filters are easier to fit

The filter supplied with Vans FI fuel pump is made by Flow Ezy. Before that pump assembly was redesigned, it used a Flow Ezy model IL6 fuel filter. I have no experience with the new pump, so do not know what filter is used now. That said, Flow Ezy makes a smaller filter, model IL4, which is much easier to install in the wing roots. It comes with 3/8" female NPT ports. This gives you flexibility to use whatever fittings your installation will require. They also come with Viton O-rings, so can handle unleaded fuels. These are available from Pegasus Auto Racing Supplies.

Pegasus part number is 3205

https://www.pegasusautoracing.com//productdetails.asp?RecID=3469

FYI, Pegasus is owned by RV-9 builder Chris Heitman. I have no relation to the company, just a satisfied customer.
 
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EFII fuel filters in each wing root

I installed an EFII FF-2 90-micron fuel filter in each wing root. I change them at each condition inspection. Access isn't bad, but spend some time thinking through the plumbing with maintenance in mind. Has worked well for 300+ hours.
 

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I installed an EFII FF-2 90-micron fuel filter in each wing root. I change them at each condition inspection. Access isn't bad, but spend some time thinking through the plumbing with maintenance in mind. Has worked well for 300+ hours.

Jeff,
Any idea of how many square inches of filter surface are inside each of those filters?
 
I just finished plumbing the fuel lines from the fuel control valve to the left tank. I applaud those who could fit another filter in between the wing root and the fuselage because there is hardly any room left to properly bend the fuel line with the minimum radius without crimping the aluminum tube. I tried not to use any AN elbow connection so my task of plumbing is a bit more challenged. I used Mikeyb suggestion of using AN union to connect the fuel lines between the tank and the control valve.
 
RV7A

My method. I change the filters each CI. 900 troublefree hours.
 

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My method. I change the filters each CI. 900 troublefree hours.

Why are your setups different from left to right? Most try to avoid that hard 90degree.. this may be better for flow..

I know you say 900 trouble free hours, but have you done the free flow tests and do you notice any difference from left to right sides?
 

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I was just at a RV10 client's place today in Savannah. He is doing his CI and has about 200 hours on the plane. Our root filter packages- Takes about 10 minutes, realistically to service the filters. LOL---takes longer to re-safety wire the shutoff valve open than it does to service the filters.

Tom
 
Why are your setups different from left to right? Most try to avoid that hard 90degree.. this may be better for flow..

I know you say 900 trouble free hours, but have you done the free flow tests and do you notice any difference from left to right sides?

Ummm, that is NOT a “hard 90*”. That is a hard 180*!
 
Curious to know how many folks are installing the performance flow filters in the RV8 wing roots. My wings are not yet installed but it looks like the fuel line coming out of the wing shares a common centerline with the same line going into the fuselage. Does this present a problem when locating the filter in the wing root? How much space is there to work with when installing the filters here? Looking for some insight. Thanks in advance for the input.

A word of caution to those adding fuel filters before the gascolator or lowest central drain point - be certain that the filter media flows water. If it is a media type that prevents water from "getting" to the engine, then you are asking for a fuel starvation engine out experience. Most marine-type (and some of the newer automotive-type) fuel filter elements are designed to prevent any water from reaching the engine (modern auto and marine fuel injection systems are water averse). The problem is: when it fills with water, NOTHING goes through. The upside though - you get to practice your glider spot landing technique ;)
 
A word of caution to those adding fuel filters before the gascolator or lowest central drain point - be certain that the filter media flows water. If it is a media type that prevents water from "getting" to the engine, then you are asking for a fuel starvation engine out experience. Most marine-type (and some of the newer automotive-type) fuel filter elements are designed to prevent any water from reaching the engine (modern auto and marine fuel injection systems are water averse). The problem is: when it fills with water, NOTHING goes through. The upside though - you get to practice your glider spot landing technique ;)

I would propose two things:
  1. Anyone who plans to place filters in the wing root should ABSOLUTELY NOT install a gascolator.
  2. Anyone not installing filters in the wing root should ABSOLUTELY NOT install a gascolator.
As for water in the gas. Would it be presumed that the operator would sump the tank drains? Is that not the lowest point in the tank, where the water would reside?
 
I would propose two things:
  1. Anyone who plans to place filters in the wing root should ABSOLUTELY NOT install a gascolator.
  2. Anyone not installing filters in the wing root should ABSOLUTELY NOT install a gascolator.
As for water in the gas. Would it be presumed that the operator would sump the tank drains? Is that not the lowest point in the tank, where the water would reside?

Not only that, It's the lowest point in the entire fuel system, and a must to sump it.
 
Not only that, It's the lowest point in the entire fuel system, and a must to sump it.

True, we should always sump, but even with sumping, there is a chance that a bubble of water could be trapped somewhere in the wing tank, or the water could be pretty well mixed in the agitated fuel. Not to mention the small problem of humans not always doing things consistently. Jeff is right - make sure that any fuel filters will flow water.

You'd probably prefer to have a bit of water flowing through the system and accept the reduced power for a few seconds over a total engine stoppage.
 
Hate to start a flame war but consider this: If block style fittings are so bad, then why is there a specified MilSpec for them, in this case a AN833-6J? Secondly, If block style is so bad then whey would Eaton Aeroquip, one of the largest Aerospace fluidline companies in the world use them as alot of their hose ends? Pics below. Sure does look like an adapted AN837 fitting to me, and measures that way too.

I'll bet that Aeroquip did alot of flow testing before settleing on this design for some of its hose ends.

Tom
 

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