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Re: Fuel delivery pressure

To: Rodney McDonald <rmcd@marspec.com>
Subject: Re: Fuel delivery pressure
From: Robert Allen <boballen@sky.net>
Date: Tue, 14 Jan 1997 16:03:02 +0000
Rodney McDonald wrote:
> 
>         Many thanks for your kind responses concerning the tire wear
> question. I've got one for my brother, also an LBC'er. He has an aftermarket
> fuel pump on his '76 'B that is delivering 7psi. Will this delivery pressure
> cause rich running? He has installed recently rebuilt SU HIF 4 carbs and has
> them leaned out all the way and it still runs rich. He has the SU fuel pump
> and intends to rebuild and install it. I'd like to convince him to do it
> before we set out for the New Orleans British Car Festival in March. Thanks
> in advance for all assistance rendered.
> 
>                                         Rodney McDonald '76 'B #393703
>                                         Spanish Fort, AL

Well, shoot. I was hoping to watch the list and not have to provide a
dissenting opinion. Oh well.

I think your 7PSI *rated* fuel pump will do fine as long as you don't
install the carb under the right rear tire. Find yourself a pressure
gauge (a combo vaccuum/pressure gauge from an auto parts store will be
okay). Measure the pressure at the pump. It should be close (cheap
gauge). Now check the fuel pressure at the inlet to the carbs. You will
notice something stole about half of it. Pumps don't maintain pressure
up hill and for long distances so by the time it gets up to the carb it
dribbles out at a useable rate.

If you're still nervous, buy Gross jets.

How do you know you're running rich? I thought them fancy single-carb
jobs would fill the charcoal cannister if the floats bobbed instead of
floated? What's your choke up to?

Bob Allen, shivering in KC, some private autos...

PS: What does Johnny Reb know about Spanish Forts? Or was that one of
them missonary strongholds right up until the Indians scalped them? Wait
a minute. I just looked it up on the map.  Right on the Gulf. I don't
have any sympathy for you.

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