[DeTomaso] Fuel Pumps

[JDeRyke at aol.com]

In a message dated 7/11/07 10:54:43 AM, charlesbuthala at yahoo.com writes:

<< Since I beefed up the engine with a large cam the calculations and the 
engine are telling me I need a larger fuel pump.  I called Carter, Holley, 
Edelbrock and found that no one makes a mechanical fuel pump larger then 80 GPH.  I 
need between 110 and 120 GPH. Any ideas.  The Summit tech help suggested an 
electronic pump that you put into the tank, at a mere $309, plus all the parts 
to hook it up and labor. >>

As mentioned earlier on the subject, school-of-hard-knocks experience by pro 
engine assemblers says with a totally stock Pantera fuel system, the fuel flow 
rate is adequate up to about 400 or so real horses. Then the limiting factor 
becomes not the pump but the inside diameter of the lines out of the tank to 
the pump, and from the pump to the carb (including the float bowl needles). If 
it's a pre-1973 Pantera, the fuel-out line goes thru a banjo fitting on top of 
the tank, that is definitely part of the flow restriction. For 450 and up 
horses actually being used for more than a second or so, a 1/2" mimimum ID steel 
supply line should be added to/from the pump. There are dependable mechanical 
pumps made by Carter available from NASCAR engine builders that work up to 
around 875 horses & 9800 rpms. You may need a second mortgage for one of these 
pumps. If you're using Aeroquip fittings, the desired size is dash-8 all the way 
from inside of the tank to the carb and many successful big-power builders 
use dash-10 sizes from pump to carb. Not doing this will certainly allow an 
occasional blast to high rpms with stock lines & fittings, but runs the risk of 
going lean at high rpms when the float bowls empty, which is usually awfully 
expensive & noisy.... 
Note also that the desirable line/fitting sizes above can be 'fudged' a 
little smaller with EFI, especially with an in-tank pump, since the pressures 
delivered are 8-10X higher and that compensates a bit for flow restrictions.  Good 
luck- J DeRyke<BR><BR><BR>**************************************<BR> Get a 
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