Mailing List lml@lancaironline.net Message #56069
From: Frederick Moreno <frederickmoreno@bigpond.com>
Sender: <marv@lancaironline.net>
Subject: Vapor lock
Date: Tue, 24 Aug 2010 09:09:00 -0400
To: <lml@lancaironline.net>

I recall that my TR-182 would vapour lock the firewall-mounted electric fuel pump on hot days.  When testing it before a start, it would spin freely indicating no pumping taking place.  Being carburetted and also gravity feed, engine hot starts were not a problem.

 

For the problems described with the small fuel injected Lycomings, one might consider putting a container around the electric and engine driven fuel pumps and gascolator, and then directing some blast air from the high pressure side of the engine baffles to these locations via 5/8 inch or one inch SCAT tubing.  The cooling flow will keep these items cool during flight, and they will not heat soak as badly after a shutdown because they start out (immediately after engine shutdown) at lower temperature, and the cans surrounding them provide some insulation from radiant heat bouncing around under the engine after shutdown.

 

My IO-550 installation kit from Lancair came with a square aluminum can that  mounts over the engine driven fuel pump and floods the exterior of the pump with cool air conveyed via a small SCAT tube.  My electric fuel pump is in the passenger side foot well per LIV normal installation procedures.  Hot starts have never been a problem.

 

I hope this helps.  It should be a readily solvable problem.

 

Fred Moreno

Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster