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Doug Dotson
 
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Default Fuel transfer/polishing pump


"DSK" wrote in message
...
Doug Dotson wrote:

This helps alot, thanks! LaBomba suggested that just amking
the primary filter bigger would solve the problem. I was thinking
that this might be a easier solution, but it appears that a separate
polishing system does have advantages over just using a filter
that does not clog up so quickly.


There is a finite amount of filter-clogging gunk in your fuel system at

any given time,
the more of it gets in your filter, the less stays in the system (and

potentially ends up
in the injector pump & injectors). A filter element that does not clog up

as quickly is
either 1- bigger and can thus hold more gunk OR 2- is letting a lot of the

gunk pass
thru. QED


The filter on the engine seems to prevent ,ost remaining gunk from reaching
the injector pump and injectors. It must since it seems to be the one that
was clogging up most.

My intended strategy is to oly
fill one tank at a time, set the newly filled tank to polishing while
running the engine off of the other tank. Then when the engine
tank gets low, switch the engine to the polished tank, then
fill and polish the other tank. That way I always have clean
fuel ready and waiting (and plenty of it) and I don;t have to rush
to fill again.


Sounds good but it might take a while.


Take a while to what? Polish the tank?



I'm still in a quandry about Raycor style filters vs the paper towel
roll type. Perhaps RichH will chime in on this one since he is an
expert on filtration systems. Does Safeway carry 15 uM paper towels?


At Trawlersfest I had two lengthy discussions with paper towel filter

advocates. Their
theory is that the random oriented strands of the paper towel can trap any

size particle,
down to sub-micron, instead of acting like a sieve to pass through

anything below a given
size (they like to avoid mentioning that the "sieve" stops anything above

it's rated
size). However they never explained why the filters don't clog up if they

are indeed
trapping particles, or why particles can't become dislodged and re-enter

the system.
Also, the paper towel systems they were advocating were all "bypass"

filters, ie on the
pressure regulator discharge rather than on the main loop, so they did not

filter more
than a small percentage of the fuel being pumped. This is due to the fact

that paper
towels can't withstand a very high differential pressure.


According to RichH, the rated size of a filter is based upon what size
particles
it can remove on a single pass. A polishing system recirculates and each
pass
through the filter removes more because a filter is much more than just a
fancy
sieve. I dunno.

Fresh Breezes- Doug King