I'll have to go look at the archives to see what changes Paul made after his
first flame out. One thing different about mine vs. Paul's, is he had
external pumps and I have internal. I'm still sceptical of this fuel heating
theory, but I'll have to put a temp sensor in my sump tank to prove anything
one way or the other. My sump tank is steel and exposed on the bottom of the
fuselage inside the naca inlet. I touch it after flight and it's stone cold.
With all the hours I have on it, I would say it's well proven by now.

BTW, I've mentioned this on other lists. When doing first flights and flight
testing of canard aircraft, especially with auto conversions, I think one
should choose an airport to fly out of with multiple, crossing, very long
runways. Have plans on what you will do if your engine quits soon after
takeoff from any runway you will use. You can't expect to just hop in an
experimental plane of this nature and fly it off a short runway as if it
were a certified plane that has been well proven. You have to expect or
assume something can go wrong at any time, even the worst possible time.

Back to luring... :)


Jim S. wrote:

That gives us two data points. Yours and Paul's first flame out. It's
entirely possible that Paul did NOT have vapor lock, and never did fix his
problem. Also possible that there's something else about your system that
makes it different enough from his to not manifest the problem. I don't
know. All I can do is the best I can with the data and experience I've
got ... Jim S.

Jim S. wrote:

There are several down sides to returning fuel to the sump (aggrivated quite
a bit as the size of the sump decreases).

Perry Mick wrote:

Don't know where this comes from? My sump is only 1 gallon and contains two
fuel pumps. Never had an issue with fuel return to the sump in 520 hours now.
I had a minor problem at one time with sump vent placement. Had a potential
major problem once when I had the sump vent temporarily plugged - BIG NO-NO!