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Re: Replacement fuel pump

To: mgs@Autox.Team.Net
Subject: Re: Replacement fuel pump
From: "Roger Garnett" <rwg1@cornell.edu>
Date: Thu, 15 May 1997 10:44:10 -0500
I said:
> > Hmm, unless you have added a pressure regulator as well, you are lucky.
> > SU's are rated for a 1.5-3.5 psi pump, anything more blows past the float
> > needles and floods over. .....

Barney Gaylord writes:

> I must have heard about 100 people make this same statement, but I'm
> beginning to think it's an old wives tale... I've never had an overflow 
>problem.

> has anyone actually experienced carburetor overflow caused by these pressures
> and not attributable to worn float valves or dirt? 

Yes, I have. Both with new gross jets (real bad) and with new needle valves 
(not as bad). It happened when I fitted an AC pump I has around when I put 
a 1275 in my Sprite, and the old engine had had a mechanical pump. I've also 
read numerous similar reports on these lists over the last 10 years. No "wives 
tales", just physics. 

Your saving may be that your pump is rated >> 3.8-5.7 psi << and not 4-7, like
many for the US market.

The SU floats just aren't rated for that much pressure- it's even listed in the
manuals. You *may* get away with it, or may not- it surely depends on many 
conditions, including float used, vibration, altitude, petrol, and more. 
proper pressure pump or adding a regulator is fairly guarrenteed to work. 

 ________________________________________________________________________
 Roger Garnett  (Roger-Garnett@cornell.edu)  http://www.wayward.team.net/
                  "The Wayward Sports Car Centre"
      "All donations of stray, orphaned, odd, neglected, etc.
       sports cars and bits in need of a good home accepted."
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