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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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