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Re: [GMCnet] Fuel Pump Poll [message #239417 is a reply to message #239370] Mon, 10 February 2014 13:16 Go to previous messageGo to previous message
jhbridges is currently offline  jhbridges   United States
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma:
Senior Member
I'll sit on the other side.  I've not had a problem with the fitted pump.  I note that mine, like most of the others I've ever seen, has a weep hole which will drain fuel in the event of a diaphragm failure.  I find that feeding the thing the fuel it was designed for keeps it going without  lot of histrionics, and keeps me - so far - from fixing symptoms.    My only concern is a fairly regular trip to San Antonio, on which no decent gas is available.  For thatr one, I drive out on good gas, load it with junk, and come home early in the day.  This in August, I've had no problems.  Comes the day no decent gas can be had, I will rethink my position and (probably) stick somebody's TBI system on it.  Having had good luck with Holley elsewhere, it would currently be the weapon of choice, but I'll ask around when I get to that point.
 
--johnny

From: Ken Henderson <hend4800@bellsouth.net>
To: gmclist <gmclist@temp.gmcnet.org>
Sent: Monday, February 10, 2014 8:00 AM
Subject: Re: [GMCnet] Fuel Pump Poll


Rob,

Fear of a ruptured mechanical diaphragm is only part of my refusal to pump
through one.

More important is the question of "why bother?".  The benefits from the
rear-mounted electric pump argue in favor of it alone vs a mechanical pump
pump alone; it then follows that in case of a failure, I'd rather have
electrical redundancy than the mechanical pump.

Then there's the question of "why through?".  It's trivially more difficult
to run the electrical pump in parallel with the mechanical pump (using
check valves), thus completely avoiding questions of pressure drop across
either of them as well as eliminating the diaphragm rupture question.

The real reason I originally installed the second pump, after deciding that
I would always have redundancy, was the abominable access to the Olds'
mechanical pump.  It was a real PITA to get to the darned thing.  The ease
of installation and maintenance of the electrical pump was child's play by
comparison, so when it came time to replace the mechanical, I resolved to
never fool with one again.

Finally, the elimination of the selector valve eliminated one more recently
failure-prone item, though mine went on to serve a new owner well.

So, while I was never paranoid about the hazard of diaphragm failure, I
just find it illogical to retain one.

JMHO,

Ken H.



On Mon, Feb 10, 2014 at 12:22 AM, Robert Mueller wrote:

> Ken,
>
> Naturally I respect your point of view, however, I'll bet JimB has
> installed lots of these little pumps which put out 1 to 4.75 psi
> and to date I haven't heard anyone noting their crankcase got pumped full
> of gas. GeneF noted that he was aware of two engines that
> got trashed when the owner moved the mechanical fuel pump with a leaking
> diaphragm from a failed engine to the new engine.
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Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
 
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