qtrmiledan
Well Known Member
Does anyone have any pics of wing root filter installs they can share? RV9 planning SDS install. Thanks in advance! qtrmiledan at cox dot net
For those needing/wanting a gascolator, thats pretty easy to do too.
Tom
Here is what I did on a -14. I am glad I did as getting to the tunnel is extremely difficult. The tank drain is the lowest point on the taildragger for water contamination and the gascolator for any debris. The Aerolab flush mounts are very nice and makes pulling and checking the screen a 2 minute job. No fairings to remove and no tools required.
Glenn,
Did you just mount the Aerolab unit on the wing / fuselage fairing? If so, is that strong enough? Looks very clean. I see you added a doubler to get the unit flush with the skin.
I got you. This is recommended by the SDS EFI fuel system manufacture, YOU...This is about an EFI install. Filters are preferred to Gascolators.
I got you. This is recommended by the SDS EFI fuel system manufacture, YOU...
I am still not 100% sure why you can not put one filter between selector and the dual fuel pump pack on the low pressure side (e.g., an Aerolab flush gascolator in cabin/cockpit floor b4 pumps aft of firewall)? The instructions just say a filter between tank and pumps. However you answered my question. Thank you very much. Cool system, great value, amazed at your ingenuity.
Each quick drain Andair GAS375 aluminum gascolators has a 49 cm2, 70 micron stainless steel woven mesh filter coated with PTFE. Suppose to prevent water to pass through the wire screen by keeping the water in droplet form. The 3/8” fuel line gascolators size are rated for a maximum fuel flow of 38 GPH, pressure tested to 100 PSI and designed to be installed on either side of the fuel pump. The screw on filter bowl is safety wired to a support bracket.
The gascolators are suspended and safety wired to the outside of the fuselage with 1/8 inch thickness aluminum angle. The flexible fuel lines in the wing root do not support or suspend the gascolators. There is no inference or potential inference with the aileron push rod or the tank vent, from any of the elements in the wing root.
An inline ball type shut off valve allows dry servicing of the gascolators during annual inspections. These valves are safety tied in the open position, after being serviced. The bottom wing root fairing cannot be installed with the ball valve in the shut-off position.
Why deviate from the proven VANS fuel system design?
After much deliberation, evaluating and weighing up the potential risks, we designed, installed and successfully tested the wing-root gascolators. The concept is not new or novel, but only one example of a RV14 with wing root gascolators is flying in Canada.
1. Transport Canada mandated a gascolator on all Canadian registered AVGAS aircraft. This regardless of the manufacturer (VANS) stating there is no need for one, nor the fact that this is a fuel injected engine.
Having said this, a gascolator is useful as a filter of sediment and water when flying to remote areas with questionable fuel supplies.
More recently (2020) TC allows “a serviceable fuel strainer and drains in the fuel tanks” as an acceptable alternative to the previously mandated gascolator.
2. The VANS supplied fuel system has an inline fuel filter mounted in the tunnel below the panel. At the annual maintenance inspection, you are supposed to open this tunnel, break the hard lines feeding the filter, (spilling the residual fuel into the tunnel and down to the main spar) to clean out the filter and then reassembling the hard lines. Due to the poor accessibility of the filter, I could not foresee that this is going to happen without some choice words.
3. With a central fuel filter down stream of the selector valve, there is no alternative fuel line supplying the engine in a situation where this single filter is clogged up by contaminated fuel.
4. In the wing root setup, the fuel from each tank is filtered before the selector valve. This gives you the option of switching tanks if one gascolator filter clogs up fully.
5. The wing root is an easily accessible location inches away from the wing tank sump that should be drained and inspected every time the fuel tank finger drains are sump.
6. The combined screen surface area of the two gascolators is 98 sq.cm, more than twice that of the single inline fuel filter (46.5sq.cm) in the VANS plans.
7. Trying to install a gascolator in the engine compartment in the RV 14 leads to two immediate problems.
a. The only possible and easily accessible position would be on forward Lt side of the fire wall. (There is no room on the right side, due to the oil cooler dumping hot air onto this position.)
b. Putting the gascolator on the Lt side as mentioned:
o adds 4 feet of fuel line between the firewall penetration and the engine mounted fuel pump.
o Apart from the added resistance and fuel flow loss, the proximity of the common exhaust pipe might induce fuel vapor lock despite heat sleeves or barriers to the gascolator.
o The cabin heat to the pilot, dumps hot air onto this position when the cabin heat source is closed.
60 hours, 1 annual and no down sides to report yet.
I did the exact same installation as described below for the same reasons on my RV7A which has been flying since 2015 (300+ hrs). No problems to report. I would do it again (for mechanical fuel injection or carburetor) .The Andair gascolators are mostly for it filtering properties.
Bevan
Mechanical fuel injection (Precision)