Frans,
Just to clarify. I have the original pump configuration, two pumps in
parallel. I have an Andair check valve in series with each pump. Several
years after I built my airplane the recommendation was to put the pumps in
series. I did quite a bit of research and I could not come up with a
compelling reason to change something that wasn't broken. With that said,
I doubt if the series pump configuration is contributing to your issue.
I have a single gascolator on the inlet side and nothing else. Like Kevin
I don't particularly care for a single point of failure, however it would
difficult to install a second gascolator now. If I were to do it over
again I would have a gascolator for each pump.
Regards, Paul
On Tue, Jul 31, 2012 at 4:27 PM, <klinefelter.kevin@gmail.com> wrote:
>
> I have an Andair mini gascolator followed by a Y splitting to Andair check
> valves before the pumps in parallel.
>
> I was chatting with Rob Seaton ( of Rotech in canada) at the Rotax display
> in Oshkosh. He recently purchased a 914 powered Europa to use as a test
> vehicle for the 912iS. We were talking about fuel system design, how the
> new 912iS has two electric pumps like the 914 except higher pressure for
> the fuel injection. He said he learned how too small a fuel line and/or
> tortured routing can cause "cavitation" at the pumps.
> I think that's the same thing, cavitation vs vapor lock? So maybe your
> fuel filter(s), on the suction side of the pump,are causing cavitation in
> the pump(s). Maybe due to the size (restriction of flow) of the filter,
> even if they are clean.
> I do not like the fact that I have a single point of failure in one
> gascolator. But if I redesign, I am going to go with less restriction,
> larger diameter tubing.
> Kevin
>
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