Glad to hear your incident did nothing more than
re-arrange your seat
cushion.  I have never had a situation of impending
vapor lock (such as
caviation of the EFI pumps) that turning on the
boost pump did not resolve.
I do however, have my fuel pumps and header tank
shielded with a fiberglass
box covered with aluminum foil.  I also have an NACA
duct funneling outside
air to the box.  So I think your plans would
certainly help the situation.
Plus, you may have a bit more heat under you cowl
what with the
turbocharger.  Other than my header pipe which do a
90 deg bend and out from
the cowl - nothing much of a heat producer, also I
do have louvers on both
sides as well as a rather large opening on the
bottom.

Hi Ed;
    Fortunately our airport is very ideal for flight
testing, with 3
separate, long runways and a relatively low amount
of traffic. I try to do
my flights when there is little traffic and I always
maintain gliding
distance to a runway. One of the benefits of the
turbocharger and the
constant speed IVO prop is that I can reach circuit
height before I reach
the end of the runway, allowing me to maintain
gliding distance to at least
one of the 6 runways at all times and I've practiced
this as well. I'm aware
of the "oh shit, this can't really be happening to
me" time lag that happens
before pilots take action, but I feel I was ready as
I run these scenarios
through my mind, before every flight, so it was an
automatic reaction to
quickly assess my options and take the best one.
While I'm pleased with the
way I handled it, I'm very angry with myself for not
recognizing the vapour
press situation developing sooner.
    As you may recall, we discussed your fuel system
off-line way back when
I was still developing mine and I felt that a larger
header tank located aft
of the firewall would reduce or eliminate the vapour
issues while adding the
benefit of a useable reserve. As I've just
demonstrated, this is not the
case. I wasn't aware that your system is shielded,
so this reaffirms my
decision to do this as well. The turbo certainly
adds to the heat creating
problems, which is ironic in that it also allows me
to quickly climb to a
safe altitude in case of problems, which it is
adding to... hmmmnn... it's a
vicious circle.
    I had earlier considered adding louvers to the
side as you have, but a
post from someone indicating that louvers are
considered to be very high in
drag, held off my decision to proceed, but I'm again
considering this. Does
anybody know of a source for an off-the-shelf
louver?

  I had considered a fuel line cooler (which they do
make), but unless you
are funneling cool outside air to it (and no inside
hot air) then it could
make the problem worst by picking up more heat from
the hotter under the
cowl air.  In any case, I have not tried a fuel line
cooler, but would think
that provided with cooling air, its couldn't hurt.

    I think that by ducting cool air through a fuel
cooler at the inlet to
the shroud around the fuel components, it should
adequately cool the fuel
without significantly heating the cooling air
allowing plenty of cooling for
the pumps and filters. I just have to find a small
enough cooler to do the
job. I also use a gascolator on one of my fuel
lines, which I'm considering
removing. I have water drains on each tank and a
sump with a drain on my
header tank, so I've never seen a single drop of
water when draining my
gascolator.
    How large is your cooling duct to your shroud
over the fuel pumps? Where
do you have your inlet for this cooling air? I
originally considered ducting
from the rad inlets, but I don't want to be stealing
any of this cooling
air, so am considering a small NACA duct on the
side.
    Leon has sent me an off-line reply with a few
additional suggestions as
well. I'm considering replumbing the header tank
vent line (which is
normally closed), back to one of the wing tanks,
instead of to the vent line
header. This would allow the boost pump to
continually recirc cool fuel to
the header tank rather than just pressurizing it.
This would also allow me
to close this vent/recirc line when I do want to
pressurize the header tank.
    The reason that I originally opted to use a
header tank was it seemed at
first to be the simplest way to manage 6 fuel tanks
without the hassle of
returning to a single tank and transferring fuel as
others have done. I've
now found that it requires much more management than
anticipated and is
becoming much more complicated. If I was starting
over again, I would
certainly reconsider this idea.

Thanks for any & all input.
S. Todd Bartrim
Turbo 13B RV-9Endurance
C-FSTB
http://www3.telus.net/haywire/RV-9/C-FSTB.htm

   "Whatever you vividly imagine, Ardently desire,
Sincerely believe in,
Enthusiastically act upon, Must inevitably come to
pass".