Re: Mandatory Mod. 40

[Carl Pattinson <carl@photos.prestel.co.uk>]

Europa wrote:
> 
> >Let me guess. Mod 40 implements a return feed. Correct?
> >
> >Tony
> 
> Yup!  Details in post.
> 
> Roger
> 
Yet another mod to upset the customers.

First we had mod 32, now we have mod 40 ! Seems to me the engine
compartment (at least where fuel lines are) is getting too darned hot.
No doubt mod 4** will mean running on 100LL as it vaporises at a higher
temp. Coud it be we're treating the symptoms rather than the cause !

Now why am I getting so upset over this mod ? Because I am now 150
worse off 25 for the mod kit and 125 for the fuel computer im going to
have to trash (not to mention the hole in my new panel). Thanks Europa !

I dare say I am not the only one with a redundant fuel computer so how
to save the situation.

Is it possible the rate that the fuel bleeds back to the tank is
constant (say 5L per hour). If this was the case then it would be
possible to recallibrate the flowmeters to take this into account. With
the Benwick system this would be very easy as it is software controlled.
Unfortunately this idea would rely on the fuel presure being fairly
constant which I doubt is the case.

Another possibility is to have a mod 41 where there is a high point in
the fuel line near the engine which is connected to a bleed chamber.
This is like the float chamber in a carburettor but the fuel enters and
leaves the chamber below the water line (in this case fuel level). If
vapour enters the system it is vented out through the float needle
valve. Plumbers use such a device in central heating systems but
unfortunately due to plastic components these are not be fuel proof. I
would be a little surprised if the automotive industry has not used such
a device at some time. Any car enthusiasts our there ?

Better still does Europa have a solution. Your comments would be
appreciated Andy.

Carl Pattinson
Kit 49