RE: Fuel Pressure

[Bob Harrison <ptag.dev@ukonline.co.uk>]

Hi!
If you have the electrical pump in series with the mechanical pump then it
constantly gets cooler fuel from the tank. The mechanical pump will pull
fuel through the electric pump even when the power to the electric pump is
switched off.
Regards
Bob Harrison  G-PTAG

-----Original Message-----
From: owner-europa@post.aviators.net
Subject: Re: Fuel Pressure


Message text written by Brian Rauchfuss - PCD
>My concern with this setup is that the electric pump side is very
vunerable to
vapor lock - while the pump is off there will be fuel sitting in the fuel
lines on the hot side of the firewall (since you merge the two lines after
the
mechanical pump) getting hotter and hotter.  After a while the line will be
filled with vapor.  Will this cause vapor lock?  Some of my reading on the
subject implies that it can.<

This should not be a problem for two reasons. Firstly there is only a very
short length of pipe from the firewall (electric side) to the point where
it joins the main supply pipe to the carburettors. This is covered in
firesleeve. The fuel further down the pipe in the tunnel should help to
conduct some heat away. Secondly there is a further bleedback point at this
join removing any remaining vapour.

Nigel Charles