Hi Mark,
I looked into installing the same kind of system early
on, but did not. I came to the conclusion (that for me and my type of
flying) that this system added no safety factor for me that running both
pumps on take off and landing did not do.
If the "automatic" system failed to turn on
your second pump (sensor failure, wiring failure, relay failure, etc), you
could spend precious seconds figuring out what is wrong and hitting your
manual override - I presume it does have that. I would assume it also
has some means of letting you know that a pump has failed, warning light?
tone?
I always take off and land with both EFI high pressure
pumps (and boost pump) running. Once at cruise altitude I switch one
EFI and the boost pump off. If pump failure should happen in that
regime of flight, I have plenty of time to observe the decreasing fuel
pressure and/or stuttering engine and switch on the other pump.
Not knocking that set up ( if designed and implemented
well), but I have a dislike of having anything critical being automatically
done for me - I'd rather do it myself. I never like talking cars
either {:>)
Ed
----- Original Message -----
Sent: Tuesday, July 24, 2007 4:24
PM
Subject: [FlyRotary] Re: FUEL SYSTEM
PRESSURE
Dave,
You've got much more actual experience than I do, but I set my system
up like the Eggenfellner guys do. They use a pressure
sensor coupled to a relay to monitor the fuel
pressures. The relay automatically turns on the second efi
pump if the pressure drops below a certain limit (determined by
the pressure sensor). That way the engine won't falter, skip, run
lean, etc. due to low fuel pressures.
The good thing about an efi system such as you have described is the
fuel in the fuel rails is always cool. Hot starts should be a
non-issue.
Mark S.