Alan,

 

Just a couple more comments on the IV and ES fuel system.  The newer planes have 1/2" fuel lines and larger vent lines running from the NACA scoops in the wingtips.  Many of us have simplified the routing of our fuel system to eliminate most or all of the 90 degree fittings.  Also, we have relocated our boost pumps to the fuselage floor in the center at the firewall.  I have 1/2" Aeroquip hose running from a straight fitting on the wing all the way to a mandrel bend 90 degree fitting on the fuel selector, no sharp 90s at all.  I'm not sure when the kits started shipping with the Andair fuel selector as standard equipment, but I think it makes a difference too.  Bottom line, between the changes Lancair made (larger fuel lines and vents) and the builder changes many of us have incorporated, the vapor suppression problems are far less likely to occur.  Especially at IO-550 fuel flows.

 

A couple ES guys who live in very hot climates have experience vapor lock on climbout.  One aircraft had been in a hangar that had ambient temperatures exceeding 100 degrees for a couple days.  Another guy has had similar experiences flying out of a southern California desert airport.  Here in Colorado, we have cool night temperatures, even with hot summer days.  I tend to fly in the cool of the morning too.

 

I take off, change tanks, land, and never turn on the boost pump.  I've never used my low boost pump, but that would be the first thing I would do if I got any engine hesitation.

 

Mike Easley

Colorado Springs

Super ES