**#1---Carburetors & Fuel Systems**
| 5/24/2010 |

Here are a few helpful formulas, calculations and tips to help you choose the proper parts for your engine.
1. When **choosing what size of a fuel pump you need **our friends at Holley offer this advice.
"Typically, at wide open throttle, full power, an engine requires 0.5 lbs of fuel per horsepower every hour. A gallon of gasoline weighs about 6lbs. Therefore an engine rated at 350 HP will require about 175 pounds (29 gallons) of fuel every hour.
(350HP x .5 lbs = 175 lbs of fuel
175 lbs/6lbs = 29 gallons per hour
29 GPH x 2 = 58gph pump required.
The reason you take the last number times 2 is that the fuel pumps sold by most manufacturers are rated a t afree flow rate and this formula, and your car, will be running at 6-7 psi or so.
2.** How do I tell what size of a carb I need?**
You take the engine cubic inch and multiply by the maxmum RPM and divide by 3456. If you have an automatic transmission you will need a vacuum secondary carb. if it is a standard transmission you can use something with mechanical secondaries. |