Roger Bull a crit :
> The reason for this is that two pumps both running in parallel
> can produce more flow than the regulator can cope with, and the pressure can
> then rise above the limit for the carburettors. With the pumps in series,
> the volume of flow will be substantially the same with either one or both
> pumps running (the pumps being more or less fixed displacement type).
>
Roger,
Did you get this information through a reliable Rotax channel ?
I was under the impression that Rotax had followed one of the Pierburg
drawing, but failed to include check valves like is advisable in any
parallel setup. The peculiar new Rotax "series/parallel" setup seems a
variation on another Pierburg schematic.
Concerning the the flow with two pumps in parallel and regulator, the
measurements we took did not show the problem you are referring to.
Some info at
http://contrails.free.fr/engine_pierburg_en.php
FWIW,
Best regards,
--
Gilles
http://contrails.free.fr
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