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Old 11-11-2010, 05:52 PM
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Sometimes I think we lose sight of reality when sizing some of these components. Let's look at basics. Engineers will tell us that most engines will use 1/2 lb. of fuel per hour for each horsepower they produce. So, if you are making....say....525 horsepower, then multiplying 525 times .5 tells us that the motor will use 262.5 lbs. of fuel at full bore, pedal to the metal top speed. Since we know that gasoline weighs about 6 lbs. per gallon, we can divide 262.5 by 6 and find that the motor will be using 43.75 gallons per hour. Now, this is at full bore, wide open. How long will you run the motor like this? Probably not more than a few seconds. But we'll use the wide open figures to size the pump anyway. Just to be on the safe side though, we will double the fuel requirement and say that this particular motor needs 87.5 gallons per hour (43.75 times 2). That is the max volume of fuel needed to operate the motor at its full rating of 525 horsepower forever.

Realizing that we do not need a pump that will pump more than 87.5 gallons per hour to operate our world beater, we would look at a pump that would deliver that volume of fuel and do it at a pressure that would not overpower the needle and seat in the float bowl. A Holley carburetor will tolerate 6 1/2 lbs. of fuel pressure, but will operate well with a safety margin at 5 1/2 to 6 1/2 psi. Here is the pump for your motor. It is all you need....If you can show me math that says differently, I will gladly listen....

These other fellows are correct about configuring the nitrous system. Consider the carburetor as one complete system. Consider the nitrous as another complete system and plumb accordingly.

P.S. Use -8 lines (1/2 inch) everywhere.
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