Re: Spica fuel pump/archive search

["Dean W. Cains" <dwc@xxxxxx>]

Hi Biba:

The restriction in the Spica pump fuel outlet does indeed slow down the 
rate of fuel flow through the pump, and in doing so, it raises the pressure 
before the orifice.  I haven't seen enough Spica pumps to know if they all 
had restrictors, and what the various sizes were.  Pat Braden once 
mentioned that a 1mm Solex carb jet was the size to use with a later Bosch 
fuel pump, and not having one of those, I drilled a brass plug.  The 
original orifice in my pump (a T255/1, on a '74 Spider) looked a tiny bit 
bigger, but also had some corrosion, which is why I replaced it.  A friend 
of mine used a air pump needle (like you'd use to inflate a basketball), 
which has an orifice about the same size, with his late-style Bosch pump on 
a '72 Spica GTV, and it works well, too.  I've seen three different types 
of fuel pumps installed as OEM on various Spica cars, and surely there must 
have been some differences in pressure and flow rate.  I've got two spare 
Spica pumps, a T255 and a T255/1, and both have similar (perhaps identical) 
restrictors.

Regards,

Dean


At 03:07 PM 5/18/2003, you wrote:

> In #502 Dean Cains makes a rather cryptic remark: "You might also have
> to play with the orifice in the fuel outlet on the Spica pump, and I
> found that a 1mm orifice works well on mine."
>
> *******
>
> Dean, you're making reference to the return line on / from the Spica
> injection pump? What is one trying to accomplish - slow down the fuel
> return to the (Master E2000) fuel pump? If so, why?
>
> Biba
> Irwindale, Ca USA
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