You've heard it before: Horsepower is stupid-easy to make these days. But in order to make big-time power, you must have two things: air and fuel. The air part is easy—it's there for the taking. Fuel has to be delivered; the days of a simple mechanical fuel pump working like an old-time, hand-operated water pump on your grandfather's farm are long gone. Today, if you want to make 500 to 800—or even a 1,000 hp—you must have a fuel- delivery system that can deliver, especially if the engine is fuel injected. But this doesn't mean the system has to be complex or include a pump the size of Cleveland. Aeromotive has just released a new Stealth fuel-tank assembly for early Camaros that offers the best of both worlds—a system that can deliver enough fuel to satisfy the hungriest power-adder street motor yet is ridiculously simple in design and execution.
The heart of Aeromotive's new system is the company's new Stealth 340 pump. At first glance, it doesn't appear that this little turbine-style pump could possibly be stout enough to feed a normally aspirated, 1,000hp carbureted engine, but that's exactly what it can do. The peak horsepower levels change when we talk about EFI or supercharged EFI because of the higher fuel pressures, but this pump is still plenty impressive. Basically, as fuel-pressure demands increase (as with EFI), volume decreases slightly, but we're still talking about delivering sufficient fuel to feed an 850hp normally aspirated EFI engine and 700 hp if that EFI engine is boosted. When you consider this pump is barely 5 inches in length and 11⁄2 inches in diameter, that's an awful lot of performance from such a small package.
Beyond the pump, Aeromotive has developed a new fuel tank for older muscle cars, allowing the company to create a similar design for OE applications that has been called "pump on a stick." This involves a fuel pump attached directly to an assembly that drops into the tank through an access hole. The key to making any high-pressure pump perform properly in an EFI environment is ensuring there is sufficient fuel around the pickup at all times. This requires a baffling system that the Stealth tank incorporates into the area surrounding the pump that allows it to continue to deliver solid fuel pressure even when the tank is nearly empty. This is critical for fuel-injected engines because if the pump's inlet is exposed to air instead of fuel (due to sloshing), the fuel pressure immediately drops, and the engine experiences a lean surge. Under full load, this can create a dangerous lean condition that could cause severe engine damage. Carbureted engines avoid this situation since they employ a fuel reservoir in the float bowl that can accommodate temporary fluctuations in fuel pressure. EFI engines don't have that luxury. While there are numerous aftermarket solutions to this problem, the simplest is to incorporate a baffle or reservoir system around the fuel-pump pickup.
The Aeromotive system has incorporated all these features into a replacement, 18-gallon, steel fuel tank that offers a large, drop-in pump and reservoir system that still fits within the confines of the stock tank's envelope. The sending unit consists of the pump, the pickup, the reservoir, a -6 pressure outlet, a -6 return-line fitting, and a -6 vent-line opening. This is all nicely recessed into the top of the tank so that it still fits flush with the floor. Aeromotive's first application is for the ubiquitous 1967–1969 Camaro, but other applications for such models as the 1955–1957 Chevy, 1964–1968 Mustang, second-gen Camaro, and 1964–1967 Chevelle are now on their way.
1. Here is the Aeromotive tank installed in our 1967 Camaro. The powdercoated tank is the same depth as stock, which means it does not hang down like other aftermarket tanks. Capacity is 18 gallons.
2. This is the Aeromotive tank assembly complete with an external fuel filter, fittings, and a carbureted fuel log for our early Camaro. Aeromotive also includes a separate 90-ohm fuel-level sending unit that is compatible with stock fuel gauges.
3. This is a tight view of the pump assembly removed from the tank. Note the integrated filter on the inlet side and the flexible return with an attenuator (Aeromotive calls it a duck bill!) on the end to reduce fuel aeration as the fuel re-enters the tank.
4. This Aeromotive drawing shows how the pump assembly integrates with the tank's internal baffling. This is crucial for any EFI application.
5. Don't let the Stealth 340's small size fool you. At 45 psi of EFI fuel pressure, this pump can produce enough volume to easily feed 700-plus normally aspirated horsepower. At 45 psi, the pump pulls about 14 amps, and as pressure increases, the amperage draws up to around 18 amps at 90 psi. This is sufficient current draw to demand a high-quality relay and circuit breaker.