Corvette Fuel Systems - Fueling The Fire

Flash back over three and a half decades. It was a gorgeous late spring day. Temperatures were in the mid to high eighties. The t-tops were off. The big block was running at full song. Seemingly in an instant, the gas pedal went spongy. The rat motor stumbled a wee bit, and then simply quit. We popped the hood in an effort to diagnose the problem. As it turned out the combination of a tight engine compartment, big compression (the factory LS6 was fitted with 12.25:1 pistons and converted to LS7 internal specifications) and big tube headers was simply too much for the fuel delivery system - big stock fuel pump and all. The fuel was percolating in the fuel bowls as well as in the fuel lines. The recurring dilemma was eventually overcome with almost every band-aid fix known to man. But it was never wholly resolved. Aside from boiling the fuel, there likely wasn't sufficient volume to satisfy a thirsty, big horsepower big block.

When it comes to fuel delivery systems, there's no question that big is pretty much the operative word. Proof is the honking fuel pump you'll typically find nestled beside the fuel cell in a NHRA Pro Stock racecar. The trouble is if you have a modified street-driven Corvette--fuel injected or carbureted--then you'll find yourself at a fuel delivery crossroad. You see, with a big cubic inch engine on board, or one with a serious power adder or two (blower, turbo, nitrous or even a combination of the three), there's a definite need for plenty of fuel. On the other hand, those big monster pumps that feed a Pro Stock drag car don't particularly like to run for extended periods of time such as in a street driven car. They weren't designed for that purpose. And heat becomes an issue (this is really critical if the pump configuration doesn't incorporate some form of return or by-pass system - deadheading pumps build heat in a big hurry). The foremost reason is there is nothing to cool the big electric motors used in these pumps.

So what electric pumps are designed for the purpose? You just have to take a look at a modern fuel injected Corvette for some insight. In those applications, the pumps are engineered so that the fuel runs through them. As a result, the fuel supply actually cools the pump as it operates. That means the pump in question can run pretty much wide open for as long as necessary (and as long as there is fuel in the tank).

Does this mean you're stuck with one of those little itsy-bitsy in-tank pumps that are found on most late model Corvettes? Not at all. Several companies offer big in-line fuel pumps that are engineered so that fuel runs through them (for extended operation). Case-in-point is the MagnaFuel 625 pump shown in the accompanying photos. This particular pump offers a number of features you should look for when shopping for a pump:

Aside from the continuous duty capability, this pump is self-priming. That means you don't have to fret about pump mounting. In fact, it is possible to install it vertically or horizontally (mount bracket included). Another bonus is the pump size. It's physically rather small, measuring just under 7.50-inches in length (not counting the fittings or the by-pass). Taking the mount bracket into consideration, the pump measures just under 3.75-inches in height while the body diameter is 3.00-inches.