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Ed's opinion reflex mine.
Georges B.
-------Original Message-------
Date: 07/28/05 10:44:14
Subject: [FlyRotary] Re: fuel filter question
Kevin,
I suspect you are correct about the design flaw.
According to the data you provided - your fuel flow capacity with the two 1/8" holes and the 1/4" common passage is way below what I have with a standard 3/8" dia fuel line.
Your two 1/8" parallel flow holes only provide a total of 0.024544 square inches of flow area. The 1/4" common passage (tube??) only provides 0.049087 square inches. Whereas the standard 3/8" dia fuel line provides 0.110447 sq inch of flow are.
So if i understand your system, it appears to me it may limit flow to only from 22 - 44 % of what the standard 3/8" line gives you. Could be I simply did not understand your descriptions correctly - but that's the way it appears to me.
If correct then that could explain why your system will not support full throttle. Also may account for the lower than expected pressure for a facet pump - mine puts out 6 psi.
So from your previous description of your troubles, I think you are able to maintain 2200 rpm simply until your float bowl is sucked down to a steady state condition (that supportable by the rate of fuel flow through your simple - which appears to be restricted) then your engine rpm drops until it reaches the rpm that the sustainable fuel flow supports and NO MORE.
My 0.02 worth
Ed A
----- Original Message -----
Sent: Thursday, July 28, 2005 12:43 PM
Subject: [FlyRotary] fuel filter question
I suspect that my engine problems stem from a design flaw, rather than a blockage. I normally never run my engine full power, full rich, but have been while breaking in the new rings. even leaning the engine a few notches prevents my problem, so it never arose in the past. my auto fuel filters are on the "suck" side, between the tanks and the selector valve. they are small, glass see-thru mesh filters. I realize now that all the fuel passes thru a pair of like 1/8" holes from a common 1/4" passage. I also see that the facet pump, despite pumping 15+ gals / hr with no head pressure, will only produce 1.75 lbs pressure when attached to the carb and bypassing the manual pump.
my question - I was told not to use a fuel injection filter on a low pressure system like mine. I would like to keep the filters where they are rather than moving them to the engine compartment, since they filter stuff ahead of my flow meter and pumps. I like how they fit along the wing spar below my knees. I had problems with the replaceable filters shedding fibers into the carb, which is why I changed to the mesh filters. does anyone know what I should be using?
I plan to do more testing this weekend if my wife will let me drive her car("no, I'm not feeling sleepy :-)" to get to the airport.
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