Budyou wrote:
>
> Gascolators do not prime well. I would check for an air leak.
Andairs are well made and pull a vacuum. The standard diaphragm pump
does not pull air well enough for some brands.
Budnow we begin to descend down the rabbit hole of the
testing and operational phase of a one-off, non-standard engine
installation...recall that my engine is MPEFI=99edmy two
(in parallel) fuel pumps are hi-pressure type and (apparently) do not
have the ability to =9Csuck=9D fuel on the input side..
> If it won't prime the engine with 2.5 gallons on the ground, will it
do it in the air?
An excellent questionfor which prudence requires an
answer =9Con the ground=9D.
>
> Ground Test war story: Ran the main dry, flipped to aux and it would
not self prime without more head pressure. Could not find a leak but
the gascolator was installed slightly above tank bottom level. With 10
gallons it would prime. It was a trigear. I know they have used
gascolators in a/c for ever, but they should be the lowest point in the
system. That is, the bowl outside, below the belly.
With my mono resting on the LG & tail wheel, I=99m
preparing a diagram with measured elevations of the various points in
the fuel system starting from the tank outlet to the hi-pressure fuel
pump outletsHowever, by eye, it is apparent that the high point
in the system is the selector-valve-main-tank-outlet(selector
valve having been installed as per manual). At this stage of the game, I
have concerns that if main tank runs dry to exhaustion and I move
selector to reserve, will fuel continue to flow?
>
> That is why I don't use them and won't install one. To easy to screw
up. Besides, water does not condense in the tanks and filters work as
well.
I=99ve been unaware of your thoughts on gascolators
I confess to have one solely because of the frequent mention of them on
this list and their apparent widespread use.
> Most experimental takeoff accidents are fuel and engine related.
I am indeed aware of that fact.
> Make them flawless then test for fuel exhaustion, on one side then
switch and hopefully keep running.
Exactly my intention...
>
> Clean your fuel lines before hooking to the engine. A common
assumption is the filter missed some dirt/ debris and the gascolators
just prior to the engine caught it. Flush and flush again.
And what do you recommend for a cleaning agent?
>
> My two cents.
Grossly undervaluedyour knowledge is priceless
Many thanks,
Fred
PS: A local A&P recommends adding a Facet pump to ensure that fuel gets
to my hi-pressure pumpsmy engine builder recommends bleeding
the lines just upstream of the hi-pressure pumpsfor the moment,
I=99m looking for simplicity and reliability.
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