Bubblehead

Bubblehead

Well Known Member
One of the draw backs of not building your own plane is you don't know what may have been done poorly or incorrectly. I bought a RV-8 in August and have been overjoyed with the RV-8 model and mostly satisfied with the particular -8 I bought. It flies really nice, is plenty fast although slightly slower than other 180 hp -8s, has acceptable radios and a nice panel layout. It's not too fancy but a good, solid, fun airplane.

However, there are a host of small things that need to be corrected. Some I've taken care of myself, some I've taken care of with the help of an A&P/IA, and some are on the schedule for this winter, which is arriving tonight! Oh, and some I'll just have to live with, like the lack of a Garmin 530W and glass panel!

Today's learning exercise has to do with the fuel system. I've looked at a lot of -8 websites and read a lot of posts here and the pictures always show a fuel filter. On the -8 it's mounted vertically on front of the left gear tower. A few days ago I took the front seat back out and crawled into the foot well to clean and inspect and low and behold, could not find a fuel filter!

The engine is an 180 hp IO-360. Are there other places that the filter could have been mounted? I took apart the fuel valve area and it is not there. I did not see it in the engine compartment when we did the condition inspection in October.

Here are two pictures, although they don't show the gear tower well. I looked long and hard at, in and around the gear tower and could not see a filter anywhere. Yes, you're going to see some dirt and debris in the pictures, but I've cleaned it up a lot already and have more to do.

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BTW, earlier I said it was "plenty fast." I lied. Nothing is ever plenty fast! I want it to go faster!
 
Bubblehead,

Some builders mount individual filters in the wing root area. Pull the wing intersection fairings and have a look there.

Guy
 
Wing root.


Possible he went without. A small spring loaded bypassing filter is located in the fuel inlet on the FI servo. If you have no other filter I would check that one every 50 hours or annual condition inspection whichever comes first.

If you do find another filter I would inspect the FI inlet filter every 100 hours or annual condition inspection whichever comes first.

There are a couple of new O rings required each time you check the FI inlet filter. Do not use the wrong kind or size.

Lots of info here:

http://www.precisionairmotive.com/servpubs.htm

They also have a CD ROM and sent it to me free.

On the cd it shows a guy tapping the filter on a piece of paper looking for crud. I did that and nothing came out. Then I took a small piece of clear tubing with an outside dia smaller than the inside dia of the filter. I stuck one end in a vacuum cleaner and taped it off to create a tiny vacuum hose. I then inserted into the filter and to my surprise was able to vacuum out a bunch of lint in a filter that looked clean. You inspect it by holding it up to the light, or sun and look for light through the weave. The the gas goes from the inside out. I told the guy at Precision about it and his exact reply was "What the hell?". Oh well guess I don't know anything. Just a stupid homebuilder nut in his eyes.
 
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Thanks to everyone posting on this. I had the root fairings off for the condition inspection in October and did not notice it then, but it may have been there. I will take another look over the holidays.

asav8tor - I'll snoop around at the precision site and get the info on the filter. Some of the other preventive maintenance, like landing gear bolts, was not well attended to so I'll bet the filter has not been cleaned in a while.

Thanks again.

John
 
Under the valve?

If it's a recently completed -8, check under the fuel valve itself.

I just put mine in about two weeks ago. That's where the plans show it, and that's where I put it.
 
Check the forward side of the left gear tower leg (if you haven't already). The builder may have mounted the filter vertically on this structure. The plans show the fuel filter mounted vertically on our F-802-L bulkhead. The 8A does not have gear towers, because our main gear are mounted to the F-804 area.
Charlie Kuss
 
Is there a gasolator & no fuel "filter"? A gasolator is a fuel filter. You "clean" it every time you drain the fuel on pre flight. During the condition inspection or "annual" you remove the bowl & screen (VERY carefully) and inspect for debris.
 
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There is definately no fuel filter in the fuel valve area, or on the front of the left gear tower. It does have a gascolator on the engine side of the firewall. I will check under the wing root fairings next.

I also contacted Precision Airmotive and talked to one of the sevice guys. He pointed me to the right documents to download from their website and is sending a CD along with the info on cleaning the filter in the FI system. He even gave me the phone number of the place to order replacement O-rings! Great service!

I appreciate everyones ideas.
 
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Bubblehead said:
There is definately no fuel filter in the fuel valve area, or on the front of the left gear tower. It does have a gascolator on the engine side of the firewall.
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Click to expand...

Ok, I don't think you mentioned that before. The gascolator IS the fuel filter. Most likely the only one. Nothing wrong with that. Some shy away from the old gascolator but they normally will provide 2 functions (1) water trap and (2) filter.

Can you attch a photo of your gascolator install?
 
Gascolator Picture

Here's a picture of the gascolator on my -8.

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I did disassemble it last month during the condition inspection and cleaned it thoroughly.

Is the gascolator enough, or should I have a filter too?
 
Bubblehead said:
Is the gascolator enough, or should I have a filter too?
Click to expand...
asav8tor said:
Ok, I don't think you mentioned that before. The gascolator IS the fuel filter. Most likely the only one. Nothing wrong with that. Some shy away from the old gascolator but they normally will provide 2 functions (1) water trap and (2) filter.

Can you attch a photo of your gascolator install?
Click to expand...
What he said.

The gascolator is the only filter I have on my -9 and the only thing many certified airplanes have.
 
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