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How To Build A Fuel System

The Key To Longevity And Maximum Power In High-Horsepower Applications Is Feeding The Thirsty Beast
February, 2009
By Henry De Los Santos
Photography by Henry De Los Santos
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Deciding how big a pump,... 
   
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Deciding how big a pump, what size lines, and which style of regulator to use can be confusing. BG Fuel Systems recommends choosing your pump based on the amount of horsepower you’re making, and then picking the right combination of parts to plumb that pump into your induction setup.
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The first order of business... 
   
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The first order of business was to swap out the AN-8 bulkhead fittings that came with our 12-gallon Summit fuel cell for the larger AN-10 fittings supplied with the BG fuel kit. First we removed the fuel door to enable us to reach in with the proper wrenches to loosen the fittings. Next we took out the foam pads in the cell and drilled additional holes for the -8 return lines.
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With the second AN-8 return... 
   
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With the second AN-8 return fitting in place, we proceeded to reinstall the cell foam after we thoroughly cleaned out the tank. The center AN fitting is for the ventilation tube, which is required by all NHRA-sanctioned tracks.
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We marked the spare-tire well... 
   
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We marked the spare-tire well for the dimensions of the fuel cell’s sump. NHRA safety regulations require a sheet of 0.024-inch steel or 0.032-inch aluminum covering the bottom and sides of the sump extending from the car. Our first idea was to cut a flap out of the factory floorpan and use that to cover the bottom of the sump, then fabricate the sides. Later, we decided it was easier to just cut the hole and weld in a separate cover to protect the sump.
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Once we were satisfied with... 
   
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Once we were satisfied with the fitting, we used a spare piece of metal to fabricate a custom cover for the sump. Here, Freiburger checks for fit after a couple trial bends. Then we tack-welded it in place.
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Next we assembled the BG 220HR... 
   
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Next we assembled the BG 220HR pumps to the massive BG 5000 filters. Starting with the AN-10 sump-to-filter supply line, we plumbed the motor side of the fuel system with an AN-8 supply-line kit from the pump to the front of the car. Ideally, the pump inlet will sit below the level of the sump outlet to gravity-feed the pump. We chose to mount the pumps behind the spare-tire well, and directly in front of the sump. We’re pretty pleased with the way the pumps tucked up out of sight with just enough room to route the supply lines cleanly out of the cell. In order to get the pump feeds to face the correct way, we had to reverse the bracket mount on the driver-side pump.
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To route both the motor and... 
   
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To route both the motor and nitrous AN-8 lines clear of the suspension and other obstructions, we used Adel clamps (arrow A) supplied with the BG 220HR kit and a few extra ones that we bought at a local hardware store. We used many existing holes and drilled a few new ones. We also fashioned tie-downs from zip ties (arrow B) that hold the braided lines together yet keep them from rubbing against each other, which will eventually fray the braided covers. Fuel flows directly into the carburetor bowl inlet via a braided fuel rail. After flowing through the rail, the fuel hits the bypass regulator and excess pressure is bled back to the tank through the return line. This keeps the fuel pressure in the system at the preset level, which we set at 71/2 psi. On the nitrous side, fuel will be pumped directly from the tank to the nitrous system’s fuel enrichment solenoid, with the excess returned to the tank. This setup minimizes the risk of a drop in fuel pressure when the system is activated.
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We used the fuel pump wiring... 
   
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We used the fuel pump wiring harness that came in the BG kit to power the pumps, which includes a fusible link connecting the pump’s hot wire directly to the battery. This prevents any fire hazards should the wire become too hot. Make sure you have solid grounds. CC

One of the most critical parts of a street/strip machine is its fuel delivery system, yet it’s frequently overlooked or underbuilt in favor of shinier, sexier parts, either because of lack knowledge or the can’t-see-it-so-I-don’t-need-it mentality. Whatever it is, the key to longevity and maximum power in high-horsepower applications is feeding the thirsty beast. Whenever you create a lot of pressure in the cylinder chambers, more fuel is required to supply the combustion.

Too little fuel can cause a lean condition, possibly leading to serious internal damage, and definitely compromising power. With reputable fuel-system companies like Barry Grant Fuel Systems (BG Systems), there is no reason to be lost in the feeding game. The folks at BG offer superior pumps individually, and better yet, have what we consider the most complete turnkey fuel systems available for applications ranging from mild street cars to full race cars. The complete kits make it easy and economical to get your fuel system put together properly the first time.

On our ’86 Mustang, we decided to install a BG 220HR pump and fuel system to feed the motor side of the junkyard 302 we’re bolting into it. Since we made 406 hp on the motor, this 220 gph pump is ideal for supplying the engine’s fuel requirement and maintaining streetability. The 220HR uses a bypass-style fuel regulator (see the Regulators sidebar) with a return line to reduce the burden on the electric pump and allow it to run continuously on the street without overheating. On the nitrous side of the equation, we have to feed an additional 250 bottle-fed horsepower without a hiccup. At that power level, we’re wary of running a single fuel system for both the engine and nitrous with this big a bottle hit, even though we know some racers who do it successfully. But for safety’s sake, we insisted on two systems. Originally, our intent was to run a second 220HR pump to the nitrous system and connect both to a single return line to the 12-gallon cell we ordered from Summit Racing Equipment. After speaking with Mike Knowles at BG, we decided that the fuel volume would be too great for a single return line and could result in abnormally high line pressures. As a result, we ended up with two complete, independent fuel systems and return lines to handle the fuel needs of both the motor and nitrous unit.

Check out the schematic for the plumbing details. It’s a bit of overkill, but it meets the unique needs of a streetable nitrous car making big horsepower. Once all the components arrived in a single box from BG, installing it was pretty simple.

BG Fuel Systems
Rte. 1, P.O. Box 1900
Dahlonega
GA  30533
(706) 864-8544
Summit Racing Equipment
Akron
OH
800/230-3030

www.summitracing.com

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