Thread: Fuel Filter
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Old 09-16-2019, 05:45 PM
Scott Hersha Scott Hersha is offline
Join Date: Jan 2005
Location: Cincinnati, OH
Posts: 1,392
Default Fuel Filter

Need some advice on where to find an acceptable fuel filter(s) for my new to me RV4. I have an O-360-A1A with a Sensenich prop. I just bought this airplane, and I’m in the initial phases of ‘making it mine’. The airplane has two Phenix Industries inline fuel filters (Aircraft Spruce) mounted in the aft end of the center tunnel and angled upwards toward the fuel selector valve. These filters are fairly large - about 6” in length and maybe 1.5” in diameter, one for each fuel tank. I’m having unusual fuel flow readings from my GRT FF servo, and the fuel pressure also fluctuates some times. I think these rather large diameter fuel filters, mounted the way they are, are cavitating, allowing air to enter the system and collecting in these filters after drainback. Downstream of the filters is the fuel selector valve, electric fuel boost pump, Flo-Scan fuel flow transducer, engine driven fuel pump, and finally the carburetor. I would like to install a couple smaller inline filters in the cabin wells adjacent to the center tunnel, mounted horizontally, which would put them below the normal fuel level in the associated wing tank, one for each tank. I want to get something that is compatible with an aircraft O-360 installation and maybe has a bypass function in case of clogging. I would need a small cleanable filter with cylindrical stainless steel mesh filter that is no more than about 4-5 inches in length so they fit in the side compartments. Any advice, please let me know.

If anyone thinks there may be other issues, please let me know what to look for. I’ve checked all fuel line connections, thinking I’m sucking air from somewhere, but everything seems fine. These filters have not been in the airplane for long.

The airplane is almost 15 years old, has 285 hours on it since new, engine and airframe, and the previous (2nd) owner put 15 hours on it in the one month he owned it. I think he did the fuel filter(s) ‘upgrade’. It runs fine, but the fuel flow has me wondering what’s going on. I can find peak EGT, but the fuel flow might fluctuate from .5 gph (@170 KTS!!) to as much as 13 gph.. fuel pressure sometimes get weird too. Makes me think there’s air in there somewhere, but I might be wrong.

If you can recommend a fuel filter replacement, or anything else, please let me know.

RV6/2001 built/sold 2005
RV8 Fastback/2008 built/sold 2015
RV4/bought 2016/sold/2017
RV8/2018 built/Sold(sadly)
RV4/bought 2019 Flying
Cincinnati, OH/KHAO
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